Model Boat Mayhem

The Shipyard ( Dry Dock ): Builds & Questions => Submarines => Topic started by: Bob K on January 15, 2017, 08:16:57 pm

Title: Resurrecting the K Class
Post by: Bob K on January 15, 2017, 08:16:57 pm
Resurrecting the K Class

I got back into model making six years ago, after a break of some 40 years.  Quite a few successful builds since then, including an (ultimately) fully operational semi-submersible.  In the Spring I intend to start building a seven foot split-hull warship with training turrets, which will be a long project as most of it will be “scratch”.

In the mean time I keep looking at my first very unfinished project gathering dust, the first RC boat I tried building after returning to model making. 
Maybe it was a bridge too far at the time, but perhaps it may be possible to resurrect my incomplete K Class submarine.  At the time I ran into too many insurmountable snags, plus total inexperience ended up shelving it, literally.  Maybe now at least I might be able get it going as a surface runner, perhaps more even. . .

So, what have I got.  A 53 inch Dean’s fibreglass hull, a fairly complete Caswell dive module (mostly in parts) that fits the hull, various micro servos, and a Futaba F14 40MHz transmitter (40MHz necessary for underwater reception.)  Also various linkages, magnetic couplers, dive planes, rudder, fail safe unit, dog-bone couplings, and a sub 10 Viper ESC.

Required:  A suitable battery to fit the forward compartment, a compatible but small Rx (the large one I bought with the Tx is in use elsewhere), plus props and shafts etc. The magnetic couplings look like they go through the module end plate, which look to need some form of corrugated rubber boots to keep the water out.  Futaba or compatible Rx’s & crystals seem tough to find nowadays. 

Six years ago I really did try to figure out how it went together, and failed.  Hopefully the intervening years of advice and experience may make me in a better position now.  I learned a lot building HMS Polyphemus and ultimately getting its dive system working.

As I have got most of the parts required I might as well have another try. There will be quite a lot of questions though.
What do you think ?

Title: Re: Resurrecting the K Class
Post by: Shipmate60 on January 15, 2017, 08:30:30 pm
Go for it Bob.


Bob
Title: Re: Resurrecting the K Class
Post by: ballastanksian on January 15, 2017, 08:46:42 pm
Given the variety of builds you have completed in the intervening years, you are surely equipped materially and emotionally to complete her.

If I may make a suggestion: To prevent any rush to deadline errors or frustrations, perhaps split the project into a pre Agincourt session and a post Agincourt session. Ok, so neither project is work related and so your schedules can be flexible, but if things go slower than expected on the sub, you can get it to a point where the project has a pause point and then resume after you have 'Big Aggie' sailing.

Going straight back in and repairing Poly is an example of your willingness to go back and complete a project, some people would have shoved her in a cupboard forever  <:(
Title: Re: Resurrecting the K Class
Post by: unbuiltnautilus on January 15, 2017, 09:01:00 pm
I am onboard :-))


Get the module up and running first. That is a purely engineering project. Then the sub, purely modelling..pretty sure you can handle that bit :}
Title: Re: Resurrecting the K Class
Post by: tonyH on January 15, 2017, 10:08:07 pm
Another stunner Bob!

Are you following the same wish list as in 2011? I haven't looked through all 7 pages yet but from what I have seen you've definitely got the 'Poly' bug again and the skill to carry it through.

Good luck and have fun :-))
Title: Re: Resurrecting the K Class
Post by: Bob K on January 15, 2017, 11:02:21 pm
Tony:  I never really had a wish list back then, apart from the K9.  I went on to build various surface warships, but have always been drawn to the challenges of unusual vessels.  Yes, not having let the Poly defeat me will be a boost.

unbuiltnautilus:  First a lot of planning to work out the best way/s of approaching this one. Both the module and model are very much interdependent.

ballastanksian:  Thanks for the vote of confidence.  I owe so much to fellow Mayhemer's and those I have met in my travels.  I have around a couple of months before "Big Aggie" hits the slipway (love your nickname), but after that there will be many pauses waiting for bits or waiting for epoxy etc to harden.

Thanks Bob: (Shipmate60)
Title: Re: Resurrecting the K Class
Post by: roadrunner440 on January 16, 2017, 01:52:10 am
oh looking forward to this..very interested...I have a caswell wtc to for my vII sub u820..2 inch dual contra rotating moters.actualy I have 2 wtc's.the 2nd I am preparing for installing a 2nd mtronics 10 esc and a action electronics p82 moter.rudder mixer and will see if I have room for the adf2 along with the lipogard and low pressure blower...im using 2 6v 1300mha 2c lipo's in series... would be interested to see your end cap/moter room..is it a 3.5inch wtc? and does it have the gas system or the the newer sas/snort system.. all mine are gas..i prefer it..cant wait to see
Title: Re: Resurrecting the K Class
Post by: jaymac on January 16, 2017, 05:30:55 am
Big article on the K class in January Marine Modelling Albeit a static  version
Jay
Title: Re: Resurrecting the K Class
Post by: Klunk on January 16, 2017, 06:23:38 am
HI Bob. Looking forward to this one. Will give any advice needed and lots if encouragement.
Title: Re: Resurrecting the K Class
Post by: tonyH on January 16, 2017, 09:45:19 am
Sorry Bob, I meant the K9 functions, e.g the disappearing funnels etc. ok2
Title: Re: Resurrecting the K Class
Post by: Bob K on January 16, 2017, 11:15:59 am
Resurrecting the K Class

Some photos needed here.  What threw me back then was the detail instructions were for a similar “Seaview” module, unfortunately looking very little like what I had in front of me.  What I have is a 2,5 inch O/Dia clear tube, 27,75 inches long, divided into three compartments. Forward is the dry battery compartment, aft is the dry motor compartment, with the floodable dive compartment in the middle.  The later has a compressed gas chamber and what looks like a float switch.  Similar to, but unlike Roadrunners photo’s.

I will start with details of the “motor” compartment.  Two small motors, a tray for four micro servos, horizontal drive outlets with dog-bone brass sockets, an aerial wire, and four holes for servo operated rods. Please excuse me if I itemise my lack of understanding on this compartment.

(http://i1143.photobucket.com/albums/n626/bobkiralfy/K%20Class/K%2016-1-17%20a_zps3xbyos6t.jpg) (http://s1143.photobucket.com/user/bobkiralfy/media/K%20Class/K%2016-1-17%20a_zps3xbyos6t.jpg.html)

(http://i1143.photobucket.com/albums/n626/bobkiralfy/K%20Class/K%2016-1-17%20b_zpsct2lziaf.jpg) (http://s1143.photobucket.com/user/bobkiralfy/media/K%20Class/K%2016-1-17%20b_zpsct2lziaf.jpg.html)

I do get the general principles of how this should work, it is just the practicalities of doing so.


Oh dear, I hear you say.  A bit like an electronic Rubic’s Cube, and yes TonyH I am daft enough to hanker for retracting funnels too.. 

Title: Re: Resurrecting the K Class
Post by: Subculture on January 16, 2017, 11:50:14 am


Depends on how many functions you want to operate, it's not obligatory to fill all the spaces. Servos can be fixed in with whatever you like, tape, drill holes for fixing screws etc.

Welcome to model submarines!

No. Rods should already be sealed with o-ring glands in the endcap.

No, don't do that, separate channels. Rear vanes should be controlled with a leveller, use the front planes for depth control.

They just click together, not sure what issues you have with that bit.

Corona do a very nice 8-channel synthesized RX on 40mhz from Hobbyking. They work well and are inexpensive.

Tandem control of motors will almost certainly help with turning. Action stuff is too big for many subs IMO. Just fit a second viper, or get a pair of microgyros esc's and use a v-tail mixer.
Common issue with subs. In reality doesn't cause much of an issue

Yes. But the joints must be soldered, and ensure the aerial length remains the original length.

Silicone rubber works well for silent and effective joints, especially when angled. Cheap too.

Position of cylinder is known on a sub, it needs to be positioned so that the centre of the ballast tank aligns with the centre of gravity. I reckon bang in between the two funnels is a good place to start.

Yep.
Title: Re: Resurrecting the K Class
Post by: Bob K on January 16, 2017, 02:09:56 pm
Awesome Subculture, that makes things a lot clearer.  Thank you.

I shall fit all 4 servos, especially as there are four holes for rods in the endplate. I may use d/sided tape as no possibility to use fixing screws. 
I do not have a leveller (yet).  I guess it can be used to operate the rear planes servo direct.
I will check on that Corona Rx from Hobbyking, hopefully can get an Tx matching crystal for it.
Proportional motor control would be nice, but heck it really is tight for space in there.
Aerial wire is into a stud thru the endcap, so I will use a soldered tag inside.
Dive module positioning:  Sounds obvious when you explain it.  Ta
I will leave that tiny snorkel pump for the mo'.  I need to better understand how it hooks up.

One step at a time.  SO glad to have the advice of a sub expert.  Appreciated.
Title: Re: Resurrecting the K Class
Post by: Subculture on January 16, 2017, 02:20:33 pm
Some levellers work autonomously e.g without a receiver input, others require one. Get a micro gyros one, best on the market and also the least expensive.

Corona receiver is synthesised, so it will bind to any frequency on your TX, crystals not required.
Title: Re: Resurrecting the K Class
Post by: Bob K on January 16, 2017, 03:02:24 pm
Corona receiver on order from Hobbyking.  Micro Gyros leveller a bit hard to find on Google.
Title: Re: Resurrecting the K Class
Post by: Subculture on January 16, 2017, 03:08:52 pm
Website not active. Better to speak to Mike directly. 0141 416 2001
Title: Re: Resurrecting the K Class
Post by: HMS Invisible on January 16, 2017, 03:17:05 pm
I do a pitch control in the AST3 but the failsafe you have should be a combined failsafe & leveller unit. I say, persevere until you encounter problems.
By the way, Fleet or Webra receivers & crystals are Futaba compatible.
Title: Re: Resurrecting the K Class
Post by: Bob K on January 16, 2017, 04:35:16 pm
I believe you are right.  It is an ADF2 "Angle Driver with integrated Failsafe (Gen 2)".  I assume that moves the rear dive planes according to its 3 axis sensor.  2 Servo leads "pitch" and "ballast", plus pins for same designations.  I assume that if signal is lost the "ballast" connector will initiate a blow ballast command as if received from the transmitter.  If I have that right - damned clever for such a tiny unit.

The "mini pump controller" is a minute PCB with a servo lead and a pair of wires.  The PCB is to be soldered direct to the pump terminals.  If it is a snorkel based system then one of the pump outlets must be plumbed into a thin vertical tube through the hull, the other should connect into the ballast chamber.  How the pipes connect from the pump will need more research.

Slowly getting there . . . .
Title: Re: Resurrecting the K Class
Post by: Subculture on January 16, 2017, 05:00:23 pm
In that case you don't need another leveller, use the one you have. A few points worth remembering when constructing the boat.

Try and make anything above the waterline as thin as possible, this reduces displacement. Thin metal and fibreglass sheet. g10 epoxy glass sheet can be purchased 10 thou thick, can be cut with scissors, yet extremely strong. Thin aluminium and steel sheet from drinks cans, slice open and flatten out.

Keep anything heavy as low in the hull as feasible.
Title: Re: Resurrecting the K Class
Post by: roadrunner440 on January 17, 2017, 01:42:40 am
nice wtc...subculture is absolutely right on all points....he or I can help out..(im not at his level  but am putting u20&u821's moter rooms back together.820's for the 2nd time due to having swsnbn's 25lb savanna cat depthcharging the whole sub&wtc off the high shelf and having to strip down&send in to have the moter shaft seals replaced...if you like I can take some better picks of the control rod setup on my s/d... also I have made a new pic/drawing of how the lipogard and adf2 are installed....as a side note the adf2 comes set to the highest sensativty..it can cause servo twitching at full power for the esc.. I am not using a dedicated failsafe as the lipogard being installed on the vent/blow servo will inhibit diveing when the batts get to low..the lipogard is run to the f/s port on the adf2 and the lead from adf2 f/s side will go to your reciver channel you want the vent/blow servo on...the angle side is easy stern planes servo to adf2 angle pins,lead from adf2 angle side to reciver channel you want stern planes on..hope that helps some



oh and don't solder the reciver lead to the stud for the antenna...just wrap it around the stud and tighten the nut..add washers if you like....the most important thing I can tell you is plan and build with the idea of being able to take it apart for service..for instance I used 2mm banna jacks soldered to the lead that comes from the forward batt room..with the male/female ends set up so b+ can never go to ground because the neg lead coming from the batt room is a male as well as the b+coming from the esc..plug them together after slideing a little heat shring over the wire plug in and shrink.now the batt/engine room leads are covered and serviceable with no cutting of the wires and having to replace/splice...
Title: Re: Resurrecting the K Class
Post by: roadrunner440 on January 17, 2017, 04:38:43 am
hopefully this will help
Title: Re: Resurrecting the K Class
Post by: Bob K on January 17, 2017, 10:57:29 am
Resurrecting the K Class

Strange how many versions of this dive module there are, all very different.  Sorry, that diagram was too small to see.  Anyway, this time a different approach.  Instead of trying to follow build ‘instructions’ on something completely different I am re-reading the published PDF’s to try to pick up on the logic of how it works, then adapting that to a working plan to construct a similar intent with what I have in front of me.

One unfortunate issue.  One of the big O rings has split (6 years old).  I will need to replicate it.   Special material?

Back to the understanding curve.  Photo below shows a micro servo linked through to the ballast chamber.  From what I can see it is the only connection through, having an arm with linkage it appears to be for both releasing stored gas and letting water in.  I am taking it that the servo lead goes to the Rx channel for combined ‘up’ and ‘down’ ballasting commands.  ie:  Stick up releases compressed gas, down lets water in.
No apparent means of connecting snorkel pump tube as yet.

(http://i1143.photobucket.com/albums/n626/bobkiralfy/K%20Class/K%2017-1-17_zpsd2fit9yz.jpg) (http://s1143.photobucket.com/user/bobkiralfy/media/K%20Class/K%2017-1-17_zpsd2fit9yz.jpg.html)

We have established that rear dive planes are automatic, via the ADF2 and one of the rear mounted servos.  Front dive planes are therefore manual, through another rear mounted servo.  Rudder uses manual Rx channel operation through 3rd rear mounted servo. Motors operated by Rx channel via ESC as in a regular boat.  Is my logic OK so far?

If so it is just the snorkel pump connections and operation to be established.  I will avoid using a Lipo, keeping it simple, and safe.

All 4 servos have to be fitted as 4 push rod holes in rear bulkhead.  Looks like I will have to use adhesive pads, and cut part of their mounting lugs off.
I may dedicate the remaining 4th rear mounted servo to lowering the funnels, at some stage. 
Title: Re: Resurrecting the K Class
Post by: essex2visuvesi on January 17, 2017, 01:38:20 pm
Good quality lipos, properly charged and maintained are as safe as any other battery type.
I wouldn't write them off as they come in all sorts of shapes and sizes and you would get the best runtimes for the space available.
Title: Re: Resurrecting the K Class
Post by: Subculture on January 17, 2017, 02:02:35 pm
O-rings are usually nitrile, you can also use silicone o-rings which tend to last longer as they not affected by exposure to the air. They are more fussy about what you use to grease them with however.  Being of American origin the o rings will be an imperial size.
Title: Re: Resurrecting the K Class
Post by: Bob K on January 17, 2017, 02:38:17 pm
Thank you Subculture.  Mike of microgyros had just emailed me a UK source of O rings, Simpley Bearings. I have ordered 5 Nitrile ones, extremely close to the measured size, and allowing for imperial dimensions.  If as you say they can be affected by exposure to air then 6 years in a box on the shelf is probably the reason one failed.
Glad you mentioned "greasing" them.  I had wondered, and if so what with.

I am currently mounting the four servos.  More later.  Mike also told me that Hiltec type servos rotate clockwise, Futaba style anticlockwise, in case I need to change one to get the rods and arms re-sorted.
Title: Re: Resurrecting the K Class
Post by: HMS Invisible on January 17, 2017, 02:51:22 pm

I hit reply on an ancient email about servo rotation. You should have said here what o-ring do you needed with a Vernier caliper measurement of the average slot diameter, tube inner diameter or the o-ring cross section in mm. The red 419 piece kit covers your size in 3.50 mm

Title: Re: Resurrecting the K Class
Post by: Subculture on January 17, 2017, 03:05:53 pm
You can use either silicone grease or petroleum grease e.g. Vaseline withNitrile. Silicone rubber you need to be careful with, silicone grease is a no no with those, ptfe grease is safe, and some people use Vaseline. You don't need to ladle it on, but just a wipe of it helps make it easy to pop the caps on and off.
Title: Re: Resurrecting the K Class
Post by: Bob K on January 18, 2017, 02:45:21 pm
Resurrecting the K Class

All your help is greatly appreciated.  :-)) 
Maybe not rocket science, but it is a black art if you have not built one before.

Moving forwards, after trying every permutation it appears the only way these servos will mount is by self adhesive pads on their sides and with part of the lugs cut off.  This leaves the underside of the tray for the ESC, the only place it will fit.  Self adhesive pads again. 

I should mention that instructions online used a single motor 3.5” diameter Ohio or a smaller Seaview dive unit.  Both radically different, and both with only 3 servo’s.  Both used lots of additional cable ties.

Back to my two motor / 4 servo tray.  It appears I can mount the ADF2 alongside the starboard servos but not quite enough room for the mini pump against the port side ones.  No room left for the Rx either, so I had to make up an additional thin aluminium tray for the other side of the front end plate.  S/adhesive pads at this stage.  At least there will be motor-grounded metal between the Rx and ESC.  Rx on the underside of this new tray, mini pump on the top.

(http://i1143.photobucket.com/albums/n626/bobkiralfy/K%20Class/k%2018-1-17_zpspfftt9pp.jpg) (http://s1143.photobucket.com/user/bobkiralfy/media/K%20Class/k%2018-1-17_zpspfftt9pp.jpg.html)

Sad I cannot use proportional mixing for the motors.  With a scale rudder this will replicate the real K’s “turning circle of a battle cruiser”.

Snag:  The lead for the ballast servo is far too short, with the connector way up inside the tube.  The Ohio version suggests using medical hemostats, so I have ordered two pairs of locking ones. 

Battery weight will need to be a guess.  International freight rules precluded shipping the one it was designed for from States. 

But, it is now all starting to look possible.

Title: Re: Resurrecting the K Class
Post by: ballastanksian on January 18, 2017, 04:08:42 pm
Hi Bob, while I was reading all the bits about fitting out your drive and control suite, I was thinking of the funnels and how to raise/lower them.

Seeing that they hinge fore and aft rather than telescope like the ones Warrior had, makes for more of a challenge.

An idea I had based on using a strong waterproof servo and a bit of brass for the mechanical bits is illustrated below.

The plate the funnels are mounted on and the swing arms would be of brass of sufficient strength to resist the springs used to return the funnels to the raised position. These should be silver soldered together for maximum strength. The hinge parts and the part of the the upper deck in which the funnels sit could be brass, though the latter could be of GRP plate to reduce weight.

The servo with gear wheel drives the wheel which pulls linkages to pull the levers thus opening the funnels tilting them over. The springs then help return the funnels to the raised position and keep the tightly shut for asthetic purposes. Using a waterproof servo and brass means you would have a system that will not rust and can be built without the added consideration of making electrical equipment watertight except for one lead to the servo from your control box. If the linkages are offset like in the image then the openings can be detailed with the boiler tops or suchlike.

Title: Re: Resurrecting the K Class
Post by: Bob K on January 18, 2017, 05:23:03 pm
Hi.  Thanks for taking the time to do that detailed suggestion.  I have to say that Subculture has already warned me about keeping superstructure absolutely minimum in weight, plus right from 2011 almost everyone tries putting me off the funnels idea - saying I should concentrate on getting the submarine working instead.

However, you know me by now I am sure. Some submariners like pop up periscopes. I'd like to see it submerge with funnels retracted - if at all possible - and after I have it sailing properly. 

The retract mechanism in practice is more like a forked arm that lifts, rotates, then lowers.  See animated .GIF below

(http://i1143.photobucket.com/albums/n626/bobkiralfy/K%20Class/retract%20animation_zpsgqmfwa6f.gif) (http://s1143.photobucket.com/user/bobkiralfy/media/K%20Class/retract%20animation_zpsgqmfwa6f.gif.html)

I found a sequence of still shots then built it up on my Gif Animator.

I'd be happy to see it running on the surface, absolutely delighted to have it dive and resurface.  This is very much an extra . . .
Title: Re: Resurrecting the K Class
Post by: Bob K on January 18, 2017, 07:27:44 pm
Resurrecting the K Class

Just had a thought.  I may be way off track here but look at the two brass tubes going through the WTC bulkhead that are coupled with a grey flexible tube in the photo below.  Nothing in the paperwork to say what this is for. 
Also, on the paperwork with the small ballast pump there is a lot about how to fit and solder the small PCB to the motor terminals, but nothing on how to connect the pump to the boat.  No other holes in ballast chamber either.

(http://i1143.photobucket.com/albums/n626/bobkiralfy/K%20Class/k%2018-1-17_zpspfftt9pp.jpg) (http://s1143.photobucket.com/user/bobkiralfy/media/K%20Class/k%2018-1-17_zpspfftt9pp.jpg.html)

Maybe I could connect the inlet side of the pump to one of these brass tubes, then connect the outer end to my external snorkel (rear radio mast). If that is correct then with the outlet side of the pump connecting through the other bulkhead tube it just leaves somehow getting that tube back inside the ballast chamber.
Only option I can think of is to stick the outlet tube through one of the 1,0 inch vent holes in the bottom of the ballast chamber from the outside and hold it in with some sticky tape. 

It would mean pulling off the tubes every time I took the dive module out of the hull.  Can’t see any other way of plumbing it in.  Does that sound right ?

If the radio mast goes under it will fill with water, rendering the snort system inoperative.
Title: Re: Resurrecting the K Class
Post by: ballastanksian on January 18, 2017, 07:38:15 pm
Oh I see. Yes, it looks more complicated with lots of exposed mechanism that would add weight by necessity. I think that concentrating on the internals is fundementally important to the success of the project.

Title: Re: Resurrecting the K Class
Post by: Subculture on January 18, 2017, 07:45:55 pm
Worth looking at materials like carbon fibre for control rods and linkages, it saves a lot of weight, and is stiffer than brass. Remember when it comes to items above the waterline, it's both weight and displacement that matters. Weight affects stability, displacement affects the size of your ballast tank.
Title: Re: Resurrecting the K Class
Post by: salmon on January 19, 2017, 01:58:26 am
The brass tubes are connected to the pump. The intake line grabs air from the surface, the output goes to the ballast tank and pushes the water out.
Title: Re: Resurrecting the K Class
Post by: Albion on January 19, 2017, 05:41:44 am
Pump connection, run tubes from your pump connections to the brass tubes currently fitted with the u hose. U hose is for shipping so you don't flood the WTC if you forget to plumb in the pump!!!


i put a hose on my snort line with a small bore brass tube on the end. This fits inside the brass tube on my main mast. When i fit the top hull i insert the small tube up inside the mast, which is high enough to breach the water. When removing the hull top section it simply pulls out. no need to keep pulling the tube off. (see poor photo)


See photos of my ongoing M1, gives a rough idea of how the cylinder fits into the hull. Also my drive shafts which are modified bone joints with square telescoping brass tube, with small pen spring inside. These can be slipped into place once the cylinder is in the hull.


Cylinder as shown is actually for the Foxtrot and has three motors, im building a new end cap which has two motors , with shafts near the bottom of the end cap and give better alignment with the drive shafts. i have 2 independant ESC, m tronic Nano (see photo). These are used in combination with Kevin Mc's throttle jockey. This allows throttle steering of the motors. its a similar size package to the APC you have. Slight left rudder - the port motor stops, full left rudder - the port motor reverses. - i'm yet to have this in the water.


Whilst the M1 doesn't have as much superstructure as the K its still fairly large for the hull arrangement. Its taken me a while to get a balance between ballast and buoyant foam.


I need to get the revised end cap working (still shoe horning all these parts into a small space), and then re check my trim with that arrangement and the final details on including the gun.


Good luck




Title: Re: Resurrecting the K Class
Post by: Bob K on January 19, 2017, 10:03:30 am
Resurrecting the K Class

That was extremely interesting and useful Albion, especially on the pump plumbing.
Supplied was a bag of loose fittings, without any explanation (see photo). 
Obvious are the 4 servo pushrods and 3 (?) magnetic couplers, but the rest ? 

(http://i1143.photobucket.com/albums/n626/bobkiralfy/K%20Class/K%2019-1-17_zpsdy9rwtso.jpg) (http://s1143.photobucket.com/user/bobkiralfy/media/K%20Class/K%2019-1-17_zpsdy9rwtso.jpg.html)

However one fitting is like the one you have connected your external pipes to.  I am taking it that I need to drill a hole through the top of the Lexan type tube and glue this over it, being careful not to block the hole. Hopefully Ciano will be OK as epoxy might spread and block the hole.
Title: Re: Resurrecting the K Class
Post by: Subculture on January 19, 2017, 10:36:57 am
You can get some very dinky esc from China for very little cash. I can't vouch for quality, they'll probably be fine, but I guess for under a fiver you take a chance.

http://www.ebay.co.uk/itm/RC-10A-ESC-Brushed-Reverse-Speed-Controller-2KHz-5V-1A-PPM-Boat-Without-Brake-/262155482821?hash=item3d09af36c5:g:hCQAAOSwMgdX1hdm
Title: Re: Resurrecting the K Class
Post by: salmon on January 19, 2017, 06:50:14 pm
Trying to attach images....


I labeled your image with what the parts are. The piece that goes on top of the ballast tank has two paths built into it. One goes to intake and one goes to the hole (that you line up on ballast tank) so it can get the output of your pump. These are on my Gato so there may be some differences. I have 4 or 5 Sub-Drivers in use.


The CliK-Ons or Klik-Ons or whatever the magnets are called are good for most connectors, you just have to make sure your planes and rudder move easily. If not you can make modifications to make them stronger. I included some pictures of a magnet connector I designed to work with the air or ballast pump for quick connects. This same design is used for some planes that are more resistant.


The strain relief gets attached to the bulkhead and the switch wire runs through it to prevent yanking it out when separating it from the battery. I had to make my own (I lost the original).
Title: Re: Resurrecting the K Class
Post by: Bob K on January 20, 2017, 11:23:09 am
Resurrecting the K Class

Many thanks Albion.  From confused to information overload.  Having seen several Engel piston type dive units this is very different, and I am trying to plan ahead to avoid dumb mistakes that I may regret later. 

I believe I may have to operate my servo arms inwards as there is insufficient space as in the illustration, but guidance to which rod guides go where was a boon.  I will fit the air pipework as detailed, leaving plenty of slack to get the motors sub assembly out without disconnecting the pipes.   I do not have metal O ring inserts for the pushrods, just holes which I assume have O rings in them. Very tight fit.

The priority is to get it working, so I will leave some improvements for later development.  a)  Use an NiMh battery to avoid LiPo / LiPo Guard complexities.  b)  Use the single ESC supplied until I can find & test dual ESC / mixer units that will fit.  c)  Whilst building superstructure in very thin Plasticard to allow for later addition of working funnels.

Should I fit an Engel type magnetic on/off switch to reduce number of end cap removals lakeside?  No switch supplied other than on the ESC, although Albion shows a switch on his end cap.

While waiting for the Corona Rx and Hemostats to arrive I need to build a lined ply box as a test tank.  The hull is too long for the bath.
Title: Re: Resurrecting the K Class
Post by: salmon on January 20, 2017, 02:13:27 pm
I use Kevin McLeod's magnet switch of KMC Designs. He is out of Canada and . It is nice and small and very reliable. I will look up his information and post it or if you visit my link, he checks there or at subcommittee.com. Sub-driver website has a retail section under a new owner, but someone who is very knowledgeable of our hobby and a great person to deal with.
Also, I have a build you can look at. https://forum.sub-driver.com/forum/builder-competitions/1743-newbie-no-more-building-the-revell-1-72-gato?1652-Newbie-no-more-Building-the-Revell-1-72-Gato= (https://forum.sub-driver.com/forum/builder-competitions/1743-newbie-no-more-building-the-revell-1-72-gato?1652-Newbie-no-more-Building-the-Revell-1-72-Gato=)
It was my first sub, but it goes through building the WTC. Including testing the wtc for leaks. Maybe it will help you on this build.
Title: Re: Resurrecting the K Class
Post by: Bob K on January 20, 2017, 07:43:53 pm
Very interesting build link Salmon, particularly on the motor compartment.  I now recall a snag we had when I bought the WTC.  The motor section is designed for a 72MHz Sombra Labs SL8.  That frequency is not permitted in Britain, and 40MHz Rx's will not fit in that tight space.  Hence my now having to redesign so much from scratch.
Title: Re: Resurrecting the K Class
Post by: Subculture on January 20, 2017, 07:47:37 pm
The corona should be a reasonable match of the sombra rx. Difficult to get an 8 channel rx much smaller with standard size plugs.
Title: Re: Resurrecting the K Class
Post by: roadrunner440 on January 21, 2017, 08:00:07 pm
I just put the motermachienraum back together after a moter shaft seal repair...your driver is like mine in set up only bigger with 2 more pushrod ports..i have some suggestions..

1 I found the reciver had to go on top.otherwise when the room was pushed in the servo wire connecters hit the vent/blow servo and made it unable to fit in... the 1st time I used zipties..to hold everthing down/secure..this time I used gm engine sealant I can give the pn# and a gm dealer near you will have it ..it has good holding strength and is easy to clean/scrape off... I started with my reciver and added 1 component at a time as I waited 24 hrs for the gms to cure 1st...

2nd   i drilled holes in the sheet metal for ease of instaltion and routeing for lpb/air pump/snort system(what ever you prefer to call it...) and other componants as well.this made things easyer for me..

3rd    wherever possible I mounted the adf2 and lipo gard to have empty pockets behind it to stuff the excess servo leads into for neatness

4th I ran the lpb pipeing next to my stern&bow plane rods..neither the 1st time or this time do they case any interfearance....

5th I used 2mm banana jacks to run the power&ground to the machienraum assy..they cant be mixed up and I put a slice of heat shrink over ithe wire put the 2 ends together and shrink over the connection..note I already have sleeved the jack ends so there is no bare metal to chaff/ground out against the sheetmetal bulkhead supports..

as to the sugestions I have drooling over your wtc this is what I would see if can be done

1 the rear 2 servo's would be stepped higher than the forward pair..the rear servo's would have the control arm/horns inbord and go to the 2 pushrod exits that are higher and inbetween your lpb/snort/pass through pipe ends..

2 the forward pair of servo's would have the horns outboard to go to the remaing pushrod ports

the area under the servo tray is where I plan to mount my 2 mtronic's viper 10's for u821's motermachinenraum..I am going to attempt to fit a action p82 moter/mixer into the space along with the lipogard and adf2 and another snort pump..yours should be big enough to mount cased esc's as I can fit 2 cased ones in theory there on my smaller one..

I hope this helps sort out the puzzle a little better.i know my 1st time around was a project in frustration for a time...so that's normal..hopfuly these give you some idea's..and while I am not at albacore or subculture's level I am a beginner as well..i have yet to do final submerged trim due to a few misshaps along the way...I think as we gain experience we tend to forget the beginning stages and take for granted how daunting it is the 1st time and so some advise from other more experienced operators is lost in translation..i find pictures to be my best teacher in some things..regards shane
Title: Re: Resurrecting the K Class
Post by: Bob K on January 24, 2017, 12:58:56 pm
Resurrecting the K Class

I have spent many hours of head scratching figuring out how to assemble this without cutting up the hardware, but . . .
It is not the manufacturers problem that I am obliged to use 40 MHz in the UK. However, the most compact 40 MHz Rx is far too large to fit in there. My only option was to do some Dremel reconstruction to widen and deepen the recess in the resin block.  The top edge of the Rx no longer fouls the tube, and the servos now virtually sandwich it.  By almost straightening out the 90 degree “Z” step in the alloy mount the servos are lowered by about 3 mm which now gives just enough clearance between the ends of the shortened servo arms and the tube wall.

Original mounting block & tray
(http://i1143.photobucket.com/albums/n626/bobkiralfy/K%20Class/K%2016-1-17%20a_zps3xbyos6t.jpg) (http://s1143.photobucket.com/user/bobkiralfy/media/K%20Class/K%2016-1-17%20a_zps3xbyos6t.jpg.html)

After reworking the cast block for larger 40 MHz Receiver
(http://i1143.photobucket.com/albums/n626/bobkiralfy/K%20Class/k%2024-1-17%20a_zpsl9voazha.jpg) (http://s1143.photobucket.com/user/bobkiralfy/media/K%20Class/k%2024-1-17%20a_zpsl9voazha.jpg.html)

40 MHz Corona Rx and servos just fit.
(http://i1143.photobucket.com/albums/n626/bobkiralfy/K%20Class/K%2024-1-17%20b_zpsivnjckau.jpg) (http://s1143.photobucket.com/user/bobkiralfy/media/K%20Class/K%2024-1-17%20b_zpsivnjckau.jpg.html)

The snort pump will go on my new bracket in front of the circular plate, and the ESC under it.  With a tiny rudder and props only 25 mm apart twin ESC’s with mixer would enable a more practical turning circle.  Can two 1A Action P82’s handle type 280 motors though?

More components now on order.  The special waterproof 2A on/off switch with boot, which I have now ordered from the USA.  I also need a 7.1V battery, and am advised that 1800 mAH should be sufficient.  2 mm ID silicone tubing for the air pump.
More 1/6 inch brass rod bought as even with the servos are in their designed position two pushrods are too short to reach the forward pair.

So, plan made.  Dry fit everything to ensure it fits.  I will need to polish the rods and make them easier to slide, form the rods to shape, then fit them.  I intend to connect up the electrics, to make sure it all works, before setting the servos in hot glue.
Title: Re: Resurrecting the K Class
Post by: roadrunner440 on January 25, 2017, 03:34:29 am
while I don't claim to be an expert ..I know the moters in my 2 inch s/d are for sure 280's ..yours must be bigger..most all the s/d'si have seen are equipped with mtronic's micro viper 10's... nautalus drydock carrys caseless micro viper 10 esc's...I will be getting 2 for the other moter room for my other s/d to go with the p82 mixer I got from action electronic's.... I don't think the action p82 1a's can handle those moters as they will pull over 1 amp current underload...I am using 2  7.4 lipo 1300mha's in parallel for 2600 mha total that's the biggest I could find so far...and that's was what was recommended by caswell when I bought it..so only 1800 mha seems to be a very small gas tank.. for full answers to your question's I recommend joining the subdriver's fourum at http://forum.sub-driver.com/forum.php...david merriman is an active member and since he made your wtc you could get it from the horses mouth so to speak..im on there as well.. good luck and keep going..you will sort it out..
Title: Re: Resurrecting the K Class
Post by: Albion on January 25, 2017, 04:30:29 am
Here's my revised module. The small Mtronics mico viper "caseless" ESC are attached to the drive motors and wrapped in Black heat shrink, you can set the set buttons sticking out.

Next to the receiver you can see the Throttle jockey , which is the prop mixer. its tiny
Title: Re: Resurrecting the K Class
Post by: Bob K on January 25, 2017, 08:55:28 am
Resurrecting the K Class

Thank you for the info guys.  It seems there are a large number of very different variants of these systems, so I am establishing generic build principles rather than specifics on the version I have. 
Nautilus Drydocks is an interesting site, but I could not see caseless Mtroniks ESC’s on there, nor on the Mtroniks web site. I will keep searching.

I did see reference to “280” motors on the smaller dive modules, but you are probably correct in that mine are not these and it might be highly risky to try P68A one amp ESCs for them.  At present I will stick with the single ESC supplied until I can be sure. 

On battery advice, I can get a single 7.4V  3300 mAh 35C pack, which looks the largest I can cram into the battery compartment.  Weighs 175 gm.  I am dubious about LiPo’s, especially about wiring them in parallel.

For now I will concentrate on the servo pushrods, which will need work to get them to slide in the seals, and to form the bends required to attach them to the servo arms. 
Title: Re: Resurrecting the K Class
Post by: Subculture on January 25, 2017, 01:01:11 pm
Think about how long you will want to operate your boat for. I rarely see modellers operate their boats for more than an hour or so. So generally you can get away with a smaller pack than you think.
Title: Re: Resurrecting the K Class
Post by: Bob K on January 25, 2017, 01:39:30 pm
Subculture:  All my other boats are surface vessels, which I run for around two hours or more.  However, I am new to LiPo's and will probably keep pulling it out every 15 minutes to check the voltage.  I would imagine weight will be more critical than capacity, but do not know what battery/s would have been supplied if they could be shipped from America.  The other unknown is what motors these are, and their full load current.
Title: Re: Resurrecting the K Class
Post by: HMS Invisible on January 25, 2017, 02:01:47 pm

...I am new to LiPo's and will probably keep pulling it out every 15 minutes to check the voltage...
No you won't. You'd use a mini led bar graph instead.
Title: Re: Resurrecting the K Class
Post by: Subculture on January 25, 2017, 02:50:44 pm
A lipo monitor is available that will blow your tank when the battery cut off is reached. It's esclusive to submarines, so not particularly cheap. An alternative would be to use one of the dirt cheap lipo monitos designed for model aeroplanes which sound a buzzer when the cut-off point is reached. Remove the buzzer and have the output trigger a strobing LED, which will give you a visual clue it's time to come in.

Those motors should be fairly modest in terms of current use, especially as they'll be driving fairly small props. Lipos can deliver much more punch than other battery tech, so I don't think you need concern yourself on motor draw. However easy enough to measure once everything is set-up.
Title: Re: Resurrecting the K Class
Post by: Bob K on January 25, 2017, 05:00:36 pm
I don't want to get ahead of my step by step game plan, but I do have a "LiPo Guard" which is supposed to blow ballast on low voltage, plus a "ADF2" electronic spirit level to control the rear dive planes.  Not gone into how they wire up yet.  (Trying to avoid an all-at-once overload). 
The 3300 mAh LiPo should give enough run time then.  I made up a foam-board model to check it fits.

I am currently working on internal servo linkages.  After that I will be positioning the dive module in the hull, with centre of ballast chamber coincident with boat C of G.
After that, planning how to make up the external linkages, using magnetic couplers.

One step at a time.    Bear with me please  %%
Title: Re: Resurrecting the K Class
Post by: Subculture on January 25, 2017, 05:13:56 pm
No problem with the battery then.
Title: Re: Resurrecting the K Class
Post by: C-3PO on January 25, 2017, 05:55:51 pm
Bob,

Whilst the Arduino is not the answer to everthing - it would certainly make an elegant and cheap solution for the Lipo cutoff voltage guard.

The basic Arduino's have 6 Analogue to Digital converters onboard - they can measure 0v -5v - so it's likely a resistor (voltage divider) will be required.

The Arduino can monitor the voltage or 6 if you wish- once the cutoff voltage is reached you can have it blow the tanks, sound an alarm , flash an LED or all 3 at once

Might be worth contacting JohnRedEarth or tscenecal ( Mayhem handles) as Arduino's and Subs are right up their street.

Googling "Arduino Lipo voltage cutoff monitor" or the like would shed some light of the subject

C-3PO

Title: Re: Resurrecting the K Class
Post by: salmon on January 25, 2017, 06:24:34 pm
When you are packing 10 pounds or Kilos into a 5 pound or Kilos space, the addition of arduino added complexity. True Arduino can do a lot for subs and are being used, but right now Bob is working through the basics of getting a sub to work. Both electronic pieces are great and will keep his sub running level (ADF2) and battery safe (LiPo Guard). I use those as well as MicroGyros products.


Bob, your doing good. Take it one step at a time and remember when it gets frustrating the goal is to finish it.
Title: Re: Resurrecting the K Class
Post by: Bob K on January 25, 2017, 06:46:52 pm
C-3PO:  If I was building HMS X-1, like Nick's (raflaunches) Dad Steve then your turret rotation programme could have been very useful.   I will be putting the Arduino turret system into the 7 foot HMS Agincourt.

Salmon:  Quite right.  I have more than enough complexity with the items I already have to shoehorn in there.

My HMS Polyphemus project was an experience that I believe now makes this one possible, a semi-submersible that took ages to get working, and sank twice, but succeeded in the end.  Knowing that a positive outcome is achievable with enough tenacity gives you a lot of confidence. 

Beware, HMS K9 will eventually be visiting a lake near you  :-))

Title: Re: Resurrecting the K Class
Post by: Davy1 on January 26, 2017, 10:41:49 am
I think that Bob is doing exactly the right thing in his circumstances i.e get something simple  together and working.

After that you can add complexity. If you are going that way and wish to add Lipos etc. I would suggest going the 433/458 MHz receiver route (developed by Tim Senecal) Lots of advantages for submarines including sending you Lipo voltage (and current draw, compass direction, depth etc) Small and cheap equipment too even with an extra Arduino for telemetry.

I haven't used 40Mhz for about 3 years now. Lipo monitors/ shut offs etc. are also a thing of the past.

But yes Bob, get it together and get it working on 40MHz first.

David
Title: Re: Resurrecting the K Class
Post by: roadrunner440 on January 27, 2017, 04:36:34 am
stay with the lipogard..sorry for the poor quality of the picture..my daughter suggested I do it in pain and save it.please be gentile I did the best I could for the 1st time and a 13yrd artist is a brutal critcic hahahah {-) the lipo gard need no set up  when low voltage it locks out the vent/ blow servo preventing you from diveing..when added to the fail safe side of the adf2 the failsafe will trigger the blow signal to the gas tank if submerged.(I don't know this for fact but I am guessing it knows submerged or not by the activity of the angle driver..if your on the surface the boat will be mostly level,no angle driver activity...submerged.pitch will be changing so it over rides stern servo to keep the model level so active signal).the stern plane servo goes directly to adf2 angle side then the adf2 to your stern plane and vent blow servo channels.this is how I did mine for reference..you will have to set up the angle driver for zerobubble ..and senseitivaty..isolate the adf2 from vibration as much as possible.and you will have to turn down the sensitivity..i had to go to lowest setting as the vibration of full millatary power on the moters can cause the servo's to twitch and the esc to stutter..(don't ask me how I know this) hope this is better than the drawing..
Title: Re: Resurrecting the K Class
Post by: Bob K on January 27, 2017, 07:07:04 am
I am extremely grateful for your efforts in producing this circuit diagram roadrunner440.   I am nowhere near the wiring up stage yet, but have saved your illustration in my "K" photo album.  It does explain a lot.  Thank you.
There are numerous "odd" flying lead ends on some of the units. 

My first LiPo has arrived.  It fits, just!.  I know everyone will assure me it will not need an underground bunker to charge it, but I am nervous of these things.  I spent most of yesterday polishing and working in servo pushrods through their seals.  More later on that 3D wire puzzle, but going well so far.
Title: Re: Resurrecting the K Class - Servo rods
Post by: Bob K on January 27, 2017, 02:33:11 pm
HMS K9.  Servo rods

Only 2 of the four servo rods were long enough, so I had to remake the other two from 1/16 inch brass rod.  Initially the rods were very tight in the seals so I started by carefully polishing those with a fine abrasive pad.  I need to strike a careful balance between just free enough for the servos to slide in them, but not too much so the seals could leak.  Once a reasonable slide had been achieved, working them further using Vaselene eased the action a little more.  This took most of Thursday and part of today.

Next was shaping the rods to the servos, having carefully looked at the various photos kindly posted.  None is quite like my set up, so I am using general principles.  The rods must move as axially straight through the seals as possible, not foul each other or the Rx, and allow full angle of movement on the arms.  It is like trying to solve a 3D wire puzzle.  Two big motor capacitor solder blobs were in direct line of the outer rods and had to be routed around.  Still needs a little tweaking.

(http://i1143.photobucket.com/albums/n626/bobkiralfy/K%20Class/servo-arms_zps6vizfzok.jpg) (http://s1143.photobucket.com/user/bobkiralfy/media/K%20Class/servo-arms_zps6vizfzok.jpg.html)

I am buying a 4 channel servo tester so that I can check out the operation of these, without having to wait until the rest of the electrics are commissioned. 

This compartment contains most of the major challenges, and will be very tight for space once everything is fitted in and wired. 

I am making some progress though . . . . . .

Title: Re: Resurrecting the K Class - Lipo
Post by: Bob K on January 27, 2017, 03:20:25 pm
HMS K9  - Lipo

Quick update.  Photo showing the 3300 mAh LiPo battery in forward compartment, which just fits as you can see.
I made up a foam board model before ordering just to check.


(http://i1143.photobucket.com/albums/n626/bobkiralfy/K%20Class/lipo_zpscxhltlr8.jpg) (http://s1143.photobucket.com/user/bobkiralfy/media/K%20Class/lipo_zpscxhltlr8.jpg.html)


PS:  Yes, my Avatar has changed, to the unofficial ships badge of HMS K9.  The motto scroll says "CANINE", and the name "GARM" is the huge dog that guarded the gates of hell in Norse mythology.  All puns, the commander had a sense of humour  {-)
Title: Re: Resurrecting the K Class
Post by: roadrunner440 on January 27, 2017, 05:49:31 pm
yay progress..as to the batt I recommend you get another and series them I can post a pic fo how I did it,,as to a good balenceing charger I recommend the thunder tiger .it will put up the model # when I get home. it works on ac/&dc comes with a power supply cord(most lipo chargers don't it also does sla /lipond lion/NiCad/nmhi batts as well it will relace all your other chargers..and reasonable cost mine was 110$ usd..I am overly paranoid about lipo's as well..don't use if dropped. I charge mine out side in the yard in a brown planter pot at a low c rate.and have never had a problem with any of the 3 sets of paired batterys I have ...I did however buy a parallel balenceing bord adapter  to use with my thundertiger ac/dc tp610...because the charger only has 1 balanceing port..but the bord was like 12$usd on ebay....keep plugging.after what I saw with the polymus boat you got this... :-))
Title: Re: Resurrecting the K Class. Servos testing
Post by: Bob K on January 28, 2017, 07:09:20 pm
HMS K9.  More progress

I have an all-types programmable charger, suitable for LiPo’s, a SKY RC e6650.  At this point I will keep to a single LiPo.  No point in complicating things.  Apart from new identical SLA’s I am dubious of parallel battery connection with the risk of one battery back charging the other.  I have one boat with twin NiMh’s, and use an Action P103 which has dual 20A Schottky diodes and heat-sink to prevent this. 
With LiPo’s?  No way !

Anyway, the little servo tester arrived.  Cost under a Fiver.  I can test each servo separately or in groups with only a 4.8V Rx battery plugged in.  No point in starting on major wiring until I can prove the servos can work the push rods OK.  With push rods operation checked out I can now hot glue the servos in place.

Planning ahead to position the dive module in the hull.  Loose fitted all the internals in the tube, and marked the C/L of the ballast chamber.  Tube volume 8.98 Litres and weight 1.10 Kilos.  The 53 inch hull is only 727 gm and will be free flooding. 
To say the module is a close fit is an understatement.  It virtually rests on the hull bottom with the hull top a close clearance. Very little fore/aft adjustment possible either, allowing for coupling the drive dogs to the props.  I intend copying the sprung loaded sliding square tube idea previously posted by Albion.

So, getting the C/L of the ballast chamber in line with the overall C of G will be near impossible in practice.  I foresee a lot of trial and error with pink foam and lead.  Too long for the bath, I will have to build a lined box for water tests.  Hopefully this can later convert to a transport box.

Title: Re: Resurrecting the K Class
Post by: jaymac on January 30, 2017, 04:13:26 pm
For those not aware yesterday was the centenary of the Tragedy of HMS K-13
sinking yards of the shore  on a test dive in the Gareloch 32 killed 48 saved
A service was held at the Navy's Faslane Base


https://www.google.co.uk/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=sinking+of+K-13in+1917
Title: Re: Resurrecting the K Class
Post by: Bob K on January 30, 2017, 05:06:08 pm
A sad anniversary indeed.  The class were so much larger faster and more complicated than any previous submarines that they suffered numerous catastrophes, collisions, and sinkings.  Having steam engines and funnels was perhaps amongst the least of their technical problems.  Designed to operate with the fleet as if a group of destroyers was asking for trouble, especially at night.  Their maximum safe diving depth was less than half their 338 feet length.
Read the fascinating book "K Boats" by Don Everitt.

I am building HMS K9, which at least survived to be scrapped in 1926.
Title: Re: Resurrecting the K Class
Post by: Subculture on January 30, 2017, 07:33:54 pm
Can we see some pictures of how far out the cylinder position is going to be. This is a crucial element in how your boat will look and perform on and under the water. It's not the same as making a boat, even one with a variable displacement, they are much more forgiving.
Title: Re: Resurrecting the K Class
Post by: Bob K on January 30, 2017, 10:01:22 pm
Fair comment Andy.  I will take some pictures tomorrow and add dimensions.  The WTC tube has 3 compartments.  Battery section 6 inches, ballast 12 inches long, and motor volume about 9.5 inches.  Most of the weight is in the rear compartment.  So with almost everything in the dive module it's C of G is four inches aft of the C / L of the ballast chamber.  Quite a lot.

If I add more weight to the battery compartment so C of G & C/L are the same point would that aid positioning the WTC in the hull ?   
Title: Re: Resurrecting the K Class
Post by: Albion on January 31, 2017, 04:42:24 am
The cylinder in M1 is as low in the hull as it can go, the front and rear of the cylinder are just clear of the hull, with just enough clearance under the mid section to fit some lead sheets. My first cylinder mounts had the module higher and more central radially, but that really doesnt work
Title: Re: Resurrecting the K Class
Post by: Subculture on January 31, 2017, 08:01:16 am
Don't worry about the weight balance of the cylinder, just concern yourself with the position of the central ballast tank.
Title: Re: Resurrecting the K Class - Dimensions
Post by: Bob K on January 31, 2017, 10:12:55 am
HMS K9.  Dimensions

Albion:  Not sure how similar the K and M class hulls are.  M1 was 45 feet shorter and a couple of feet narrower.  However, getting a 2,5 inch dive module in there leaves little latitude for moving the WTC around.

First picture shows my dive module, with inner lengths of compartments. The centre of the ballast chamber is 12 inches from the front.   I have loose fitted almost all the components, and the centre of mass is almost 4 inches rearward of that.

(http://i1143.photobucket.com/albums/n626/bobkiralfy/K%20Class/dimensions%201_zpsygpjsp5k.jpg) (http://s1143.photobucket.com/user/bobkiralfy/media/K%20Class/dimensions%201_zpsygpjsp5k.jpg.html)

With the tube laying in the hull it is a close fit inside.  There is about 3 inches fore / aft movement possible between the forward hull narrowing and before prop shaft exits become impractically close to the rear.  Maybe up to half an inch of vertical movement under the hull top.  Moving the tube back and forth within its limits make less than an inch difference to the overall C of G balance point.  Hull mass is only 727 gm.

(http://i1143.photobucket.com/albums/n626/bobkiralfy/K%20Class/dimensions%202_zpsuv9wv1x0.jpg) (http://s1143.photobucket.com/user/bobkiralfy/media/K%20Class/dimensions%202_zpsuv9wv1x0.jpg.html)

I hope this explains it a bit better.  It does not seem possible to get the C of G coincident with the centre of the ballast chamber without getting the rear of the dive module well aft of the prop shaft outlets, where the hull is far too narrow to for it anyway.
Title: Re: Resurrecting the K Class
Post by: Subculture on January 31, 2017, 02:16:13 pm
With the current arrangement you will have to either accept a very unscale like waterline with the bow up in the air and the stern squatting down in the water, or the c.o.g is going to have to be moved further forward than is desirable. A far forward c.o.g will make the boat more forgiving, but it will make the boat tend to weathercock more when turning, and will make it less agile.

There are alternative solutions, but they would involve radical alteration of your present dive module, which I can quite understand you would be reluctant to do.

The chap that owns Mountfleet models scratchbuilt a K-class in a larger scale. You may wish to get in touch with him via his website contact and pick his brain on the handling.
Title: Re: Resurrecting the K Class
Post by: Bob K on January 31, 2017, 03:11:51 pm
Woops, looks like I have problems then.  I am unsure what battery (and therefore weight) was intended for the forward compartment.  (LiPo's could not be shipped from the States.)  Maybe a lot heavier than the 3300 mAh I am using?  Why else was the ballast chamber centred so far forward?

Silly question (please excuse me) but with just a 150 gm bag of lead shot low in the point of the bows I CAN get the combined hull and dive module to balance longitudinally right under the centre of the ballast chamber, with just enough room to connect prop shafts. 

I understand that not only should it be on a level keel on the surface (with empty ballast tank) but should remain on a level keel when submerged.  Catch 22 to achieve ?

Would my extra 150 gm in the bow still balance it with a half full ballast tank, provided the o/a ballast centre remains over the C of G ?
Title: Re: Resurrecting the K Class
Post by: Subculture on January 31, 2017, 03:39:41 pm
I don't disagree you can get the boat trimmed. What you're not taking into account is that there are three main sets of forces acting on a sub which affect the way it handles (affects boats too, but the affects are a little more benign, at least at low speed).

You have gravity pushing down and buoyancy pushing up, these are static forces, and with the two aligned on your boat surfaced and submerged, it should maintain an even keel no matter where along the keel those two forces align.

The third force is pressure acting on the hull as it moves through the water. A dynamic force that dictates heavily how the boat will handle. Ideally on most subs the centre of pressure will be acting a bit forward of the longitudinal centre of the boat. If it's aft of centre the boat will be unstable and skittish, further forward and it will be more stable, too far forward and it'll be too stable.

BTW. Not  sure what you used to calculate the volume of the cylinder, but no way is it 8.98 litres. I calculated 2.2 litres.
Title: Re: Resurrecting the K Class - bulkheads
Post by: Bob K on February 03, 2017, 09:24:21 pm
HMS K9.  Bulkheads

OK.  Dive module positioning is defined by Hobson’s Choice.  The ballast chamber being so far forward in the tube, plus the unknown weight of the battery that it was designed for.  150 gm of lead low in the bow the only way to avoid having the tube almost hanging out the back of the hull, but at least the centre of the ballast chamber matches the overall C of G, and allows prop shafts to be fitted, albeit very short ones. 
I really do not expect a K Boat to steer well, the real ones didn’t, and had volatile pitch control.  It is after all a long thin spindle with a tiny rudder and planes.

Taking advice I will try to mount the tube as close up under the upper hull as possible, but no higher than the surfaced waterline.  Three supporting bulkheads, the centre one being positioned for the dive module alignment spigot hole. A Velcro strap will go around the centre of the tube.  The supporting bulkheads are taking time to shape. “U” shaped cutouts for the tube will be added, plus holes to allow water flow and reduce weight.

(http://i1143.photobucket.com/albums/n626/bobkiralfy/K%20Class/K%203-2-17_zpsxc4p9niq.jpg) (http://s1143.photobucket.com/user/bobkiralfy/media/K%20Class/K%203-2-17_zpsxc4p9niq.jpg.html)

Positioning the “U” cutouts will be critical, there is not a lot of clearance.
Title: Re: Resurrecting the K Class - Bulkheads part 2
Post by: Bob K on February 14, 2017, 02:08:19 pm
HMS K9.  Bulkheads Part 2

Sorry for the delay.  Forming those bulkheads took a lot longer than I thought.  Loads of intricate internal measurements and calculations as the hull shape precluded use of profile tools. The aim being to get the top edge of the dive module about 5 mm above the intended waterline.  However, it is still very close to the bottom GRP hull.

I also had to allow for the lower hull needing to be pulled in a little at the top, to line up with the upper hull edges.  This involved making a fourth bulkhead.  Each bulkhead had to be fitted and epoxied as a separate operation, with the dive module in place to ensure an accurate fit, with localised hull width clamping.

(http://i1143.photobucket.com/albums/n626/bobkiralfy/K%20Class/4%20bukheads_zpsoh0duggy.jpg) (http://s1143.photobucket.com/user/bobkiralfy/media/K%20Class/4%20bukheads_zpsoh0duggy.jpg.html)

Next up will be constructing the 60 inch long test tank, which will later double as a transit case. 

PS:  The special 2A switches with boots, (manufacturers part numbers were quoted in the SubDriver data,) duly ordered from the USA - finally arrived.   From Thailand !!!
Title: Re: Resurrecting the K Class - Test Tank
Post by: Bob K on February 20, 2017, 04:28:59 pm
HMS K9.  Test Tank

The hull for HMS K9 is too long for the bath !

The dual purpose test tank was fabricated from 5.5mm plywood, sixty inches long, seven inches wide, and eight and a half inches deep.  Corners will be reinforced with wood mouldings, pined and glued.  It will be temporarily lined with pond liner for ballasting and buoyancy tests. 

After commissioning the plywood tank will be converted into a transit case for the submarine, to protect the vulnerable planes, rudder, props, upper-works and masts.  All it will need is to replace the waterproof liner with shaped foam hull supports and end protectors.  The height of the box will be sufficient to guard the two radio masts, one of which will double as a snorkel for the low pressure air pump. 

(http://i1143.photobucket.com/albums/n626/bobkiralfy/K%20Class/case_zpshnj9oguw.jpg) (http://s1143.photobucket.com/user/bobkiralfy/media/K%20Class/case_zpshnj9oguw.jpg.html)

Fuse ?

There is no mention anywhere in the info about fitting a fuse.  Strange, as a LiPo battery has the potential to deliver extreme current for short periods.  I intend to fit a two bladed 15A car type fuse and holder in the battery compartment.

Title: Re: Resurrecting the K Class
Post by: Subculture on February 20, 2017, 05:35:10 pm
Is the coffin shape a bit of dark humour?
Title: Re: Resurrecting the K Class
Post by: Bob K on February 20, 2017, 07:21:59 pm
Is the coffin shape a bit of dark humour?

Not at all Subculture.  The case is tapered at one end to fit diagonally in my small car. 

The "short" end fits more easily in the corner of the rear seat behind me.  The width allows plenty of clearance for the delicate dive planes when lowered into the shaped foam cradle for transit.  Three inches each at front and rear for bow and stern protectors.  The 53 inch hull, at 1/96, indicates how large these submarines really were.  The model will be longer than many modern warships at the same scale.

(http://i1143.photobucket.com/albums/n626/bobkiralfy/K%20Class/K3%20Vickersjpg%20small_zps5prenyuo.jpg) (http://s1143.photobucket.com/user/bobkiralfy/media/K%20Class/K3%20Vickersjpg%20small_zps5prenyuo.jpg.html)
HMS K3 under way

(http://i1143.photobucket.com/albums/n626/bobkiralfy/K%20Class/KatGosport.jpg) (http://s1143.photobucket.com/user/bobkiralfy/media/K%20Class/KatGosport.jpg.html)
HMS K3 model at Gosport
Title: Re: Resurrecting the K Class
Post by: raflaunches on February 24, 2017, 07:58:33 pm
Hiya Bob


Excellent work on the resurrection, I've just bought two 1/350 scale models kits of the two types of K class sub- as built and the swan bow, they are produced by Mikr Mir and after starting to build the original type it goes together well so I've got some inspiration not only from yourself but a completed model (albeit smaller). :-))
Title: Re: Resurrecting the K Class
Post by: Bob K on February 24, 2017, 08:42:36 pm
Thank you Nick.  As you know I have a penchant for unusual warships.  Glad your 1/350 scale K Boats are going together well.  I prefer the original version myself.  The bulbous swan bows may have been a more seaworthy improvement but somehow made them look visually odd.  My build is going to be a long one as almost everything so far seems like a specialist 'black art', virtually a 'scratch'.  I have spent 4 days trying to contact Prop Shop to try to source the unusual four bladed propellers, which will define the positioning of the special sliding prop shafts. 

The 'coffer' (not coffin) is nearly completed. Just needs finishing and some pond liner.  The wet testing will be complicated by all accounts.  With the dive module in place I can start planning all the internal linkages, for which I have acquired a small pillar drill.  Brass bushes with silver soldered arms, and grub screws. 

I am trying to avoid thinking about building the detailed superstructure at this stage, the part I will enjoy most.

PS:  Good luck with completing the train ferry deck planking before going back to the Med'.  Can't wait to see your Dad's inter-funnel girder completed.
Title: Re: Resurrecting the K Class
Post by: ballastanksian on February 24, 2017, 08:50:14 pm
They have moved the rebuilt bevel gear exhibit that used to live in the Submarine. A sub stripped its drive gear and the engineer aboard had to rebuild the teeth using a drill, lengths of rod and hand files to shape the rods to match the teeth all while trying not to be discovered by the enemy in WW2.

They were a hard bunch Submariners  :-))

Look on the bright side Bob, you are learning so much about this project it will soon match Poly in the challenge stakes.
Title: Re: Resurrecting the K Class - Props & Shafts
Post by: Bob K on February 27, 2017, 04:16:08 pm
HMS K9.  Prop & Shafts

Moving on from the Coffer (not coffin), the next fiddly bits are the prop shafts.  These are designed for dog-bone couplings and imperial size shafts.  Of necessity space is very tight due to having to fit the dive module as far aft as possible, and also results in the shafts being slightly angled to the motor couplings. 

The outer shafts go through the hull, aimed to line up with the motor couplings then shortened to around 120 mm.  “A” frames to be fitted at the rear.  Rather than use a 1/8” dia shaft I am using 3 mm (for M3 shafts) with a thin coat of paint on the inside of the 1/8 coupling. Only 0,2 mm difference, but . . .

I was so impressed by Albion’s sliding telescopic square-tube shafts with internal springs, and am trying to replicate these.  Dog-bones cut in half, the ends fitted with screws into the outermost square tubes.  The slightly larger sliding tubes have stainless springs that maintain compression on the dog-bones, whilst allowing latitude for dive module removal.  The entire shaft system is in the flooded part of the hull so will need to be cleaned and lubed regularly.

Getting suitable props took some time.  After almost a week of calls and emails to Prop Shop I still had no response.  The nearest non-custom I could find were Raboesch 4 bladed type “D”.  Unfortunately Dean’s were out of stock, but I was able to order them from Cornwall Model Boats.  … but a week lost !

(http://i1143.photobucket.com/albums/n626/bobkiralfy/K%20Class/K4%203_zpswpl6md5j.jpg) (http://s1143.photobucket.com/user/bobkiralfy/media/K%20Class/K4%203_zpswpl6md5j.jpg.html)

While the props are on their way I thought I should start work on the hull perforations.  Plenty around the keel, plus a series of rectangular ones along the hull.  Not much visible on top apart from superstructure, so I need to ensure that there are enough elsewhere to prevent air being trapped especially at the bow and stern. 
Title: Re: Resurrecting the K Class - Venting the hull
Post by: Bob K on February 28, 2017, 03:06:45 pm
HMS K9.  Venting the hull

Very little information online as to how the free flooding volumes were vented, apart from rectangular openings along the sides of the hull and rows of small holes almost on the waterline of the bows.  Lots of tank vent caps, but I need holes to avoid trapping air inside.  So, I am putting some in where needed.  A long line of slots in the keel (I know, these are the drop keels) and patterns of small holes atop the bow and stern ends. 
The removable upper section of the hull will rely on venting through the superstructure.

(  Not sure how clear the small holes will appear on this photo of the 1.35 m long hull  )

(http://i1143.photobucket.com/albums/n626/bobkiralfy/K%20Class/hull-holes-2_zpscerc2izp.jpg) (http://s1143.photobucket.com/user/bobkiralfy/media/K%20Class/hull-holes-2_zpscerc2izp.jpg.html)

Below are the style of propellers I have ordered.  Not too dissimilar from the photo in my last post.

(http://i1143.photobucket.com/albums/n626/bobkiralfy/K%20Class/Raboesch%20D_zpsdcjkfrz0.jpg) (http://s1143.photobucket.com/user/bobkiralfy/media/K%20Class/Raboesch%20D_zpsdcjkfrz0.jpg.html)

When the props and shafts arrive I can start building the sprung-telescopic drive system. 
Title: Re: Resurrecting the K Class - Hull halves joining
Post by: Bob K on March 03, 2017, 04:45:18 pm
HMS K9.  Hull halves joining

Waiting for prop shafts so started on joining the two halves of the GRP hull parts.  To start with there was quite a bit of mismatch on the joint edges, which is to be expected.  Started by linishing the edges using a large sheet of emery on a flat board.  Then fine-dressed the joint edges with a long fine file to gradually reduce high spots.  Eventually got a reasonably good joint line. 

(http://i1143.photobucket.com/albums/n626/bobkiralfy/K%20Class/hull-join-1_zpstouvbe3r.jpg) (http://s1143.photobucket.com/user/bobkiralfy/media/K%20Class/hull-join-1_zpstouvbe3r.jpg.html)

A 2mm thick strip of styrene on the inside edge for the hull bottom front, with a 1 mm alloy bracket epoxied under the leading edge of the hull top to provide a location support.  An alloy strip under the rear edge of the hull lip for a fixing point. Lastly two layers of litho strips along the inner horizontal edges to  complete the hull location supports.

(http://i1143.photobucket.com/albums/n626/bobkiralfy/K%20Class/hull-join-2_zpsjbkiygdz.jpg) (http://s1143.photobucket.com/user/bobkiralfy/media/K%20Class/hull-join-2_zpsjbkiygdz.jpg.html)

Well, whilst I was doing that the prop shafts have arrived. 
Now I can get onto the sliding telescopic tube shaft adaptors.  More on that soon . . .

Title: Re: Resurrecting the K Class
Post by: mountfleet on March 03, 2017, 08:44:45 pm
Hi bob, I always thought k's had 3 blade props.
Adam
Title: Re: Resurrecting the K Class
Post by: Bob K on March 03, 2017, 10:14:27 pm
Hi bob, I always thought k's had 3 blade props.
Adam

Hi Adam.   See photo in Reply #82 below, 28 February
Title: Re: Resurrecting the K Class
Post by: Subculture on March 04, 2017, 05:30:28 pm
Adam is correct, they are three blade props. Look at 2:20 on this dive of the wreck of K17.

https://www.youtube.com/watch?v=7nFUYhxB3T8
Title: Re: Resurrecting the K Class
Post by: Bob K on March 04, 2017, 06:50:04 pm
K4 definitely had four bladed props, of the round blade style as in the photo below, rather than the more pointed type in that video clip of K17.  They were produced in seven separate shipyards.  K17 was the last built before resdesigning them as monitors and an seaplane carrier.  K18, 19 & 20 became M1 to M3 and were not steam powered.

I am sticking with the clear photo of HMS K4's 4 bladed prop, taken when she ran aground on Walney Island in 1917, which also matches the plans I have.
Title: Re: Resurrecting the K Class
Post by: Subculture on March 04, 2017, 07:02:02 pm
But looking at the pictures, the props look more like three blade to me.

I can only see a pair of blades in the picture, but if four blade then the two blades pictured would be at ninety degrees to one another, but they're not. They look more like 120 degrees to me.
Title: Re: Resurrecting the K Class
Post by: Bob K on March 04, 2017, 07:16:03 pm
Looks quite clear to me.  You can see the 'rounded' blades, at 90 degrees radially.

(http://i1143.photobucket.com/albums/n626/bobkiralfy/K%20Class/K4%203_zpswpl6md5j.jpg) (http://s1143.photobucket.com/user/bobkiralfy/media/K%20Class/K4%203_zpswpl6md5j.jpg.html)

Title: Re: Resurrecting the K Class
Post by: raflaunches on March 04, 2017, 07:49:12 pm
Hi Bob


Unfortunately it looks like you fell into the same trap as me, this picture from K-Boats should clear things up.


(http://i63.tinypic.com/mcvym9.jpg)

(https://i.imgbox.com/jrHtezVH.jpg) (http://imgbox.com/jrHtezVH)
Title: Re: Resurrecting the K Class
Post by: Subculture on March 04, 2017, 08:03:06 pm
The red is a 90 degree angle. nowhere near the middle of the second blade.

Title: Re: Resurrecting the K Class
Post by: Bob K on March 04, 2017, 08:32:05 pm
You can't argue with photographic evidence.  If there were only 3 blades those two would be at 120 degree, and they clearly are not.  You can also see part of the third blade with the bottom of the rudder slightly overlapping it.
You can't see the 4th blade as it is underwater.    No - don't try to say it is an optical illusion as it is 180 degrees from the port-most blade, and at least part of the blade would be visible even if it were a triple .

We can clearly see three of the blades, two of which are at 180 degrees.
Title: Re: Resurrecting the K Class
Post by: raflaunches on March 04, 2017, 08:40:43 pm
Just to throw some more confusion it looks like K26 had at one point have four bladed propellers judging by a drawing in Paul Akermann's book Encyclopaedia of British Submarines 1901-1955.


I've had a quick swim through the technical bits in both books I've mentioned and it doesn't confirm the propeller design but it does go in to some detail about engine and shaft layout and designs but never mentions the props other than that there were two of them!
Title: Re: Resurrecting the K Class
Post by: Subculture on March 04, 2017, 09:52:33 pm
Can't see any third blade in that picture, just two.

Here's the same image with a line also at 120 degrees, that to me looks broadly in line with centre of the blade.

Title: Re: Resurrecting the K Class
Post by: Bob K on March 04, 2017, 10:29:01 pm
Nick, you are right in that all the technical data goes on about everything in the propulsion system except the number of blades.  As you know I have been researching these on and off for six years and I must have just about everything published on them.  At the time built, and designing for maximum speed, four blades were also used for many surface ships.  I am currently re-trawling the "K Boats" book for the umpteenth time.

Personally I am satisfied with my decision based on the evidence I have.
Title: Re: Resurrecting the K Class
Post by: Colin Bishop on March 05, 2017, 03:55:09 pm
The Micro Mir kit shows 4 bladed props on K4: http://www.britmodeller.com/forums/index.php?/topic/234986377-british-k-class-submarine-mikro-mir-1350-scale/

Also the photo here taken from the bow shows the 4 bladed prop very clearly: https://forums.spacebattles.com/threads/k-for-katastrophe-the-odyssey-of-k-class-submarines-in-the-royal-navy.366780/

The photo taken from the stern is distorted, probably due to the lens being used which makes the prop look disproportionately large.

Colin
Title: Re: Resurrecting the K Class
Post by: Mortimer on March 05, 2017, 04:48:42 pm
I don't know if this helps or if it complicates things but the propulsion specs in the general characteristics box here show three blades:

https://en.wikipedia.org/wiki/British_K-class_submarine

 and the instructions for the 1/350th model show three blades:

http://www.modelwarships.com/reviews/ships/hms/k-class/350-cs/k-class-05.jpg
Title: Re: Resurrecting the K Class
Post by: Martin (Admin) on March 05, 2017, 04:49:50 pm

OK, we'll leave the three, four propeller question at that,  it's Bob's interpretation and decision after all.

Not unheard of for ship makers to use different types of props after test, trails and refits.

   ..... moving on!   :-))
Title: Re: Resurrecting the K Class
Post by: Subculture on March 05, 2017, 05:51:31 pm
Has my post has been deleted. If so on what grounds?
Title: Re: Resurrecting the K Class
Post by: Martin (Admin) on March 05, 2017, 06:18:33 pm
 
Third Repeat post 
Title: Re: Resurrecting the K Class
Post by: derekwarner on March 06, 2017, 12:31:05 am
Morning Subculture :o...I must admit of not knowing that Willie of the Shakesphere wrote or penned that phrase {-)

We think of manganese and Naval Red brasses as brittle, however such a propeller casting that has been machined would have surprisingly high impact resistance and fracture or shear strength properties

My only constructive thought is that with some 2000 tons of mass possibly pivoting on the propeller blades when the vessel came to rest is that one if not more of the blades became grossly distorted %)

This may have distorted the propeller blade geometry as depicted in the image of the beached submarine

Derek
Title: Re: Resurrecting the K Class
Post by: Ian K on March 06, 2017, 06:48:40 pm
Hi,

Just to add my view on the prop issue......

The K boat pictured is fitted with 3 blade screws, don't confuse the mud/sand bar she has settled in as a 4th blade.
Subculture is correct, with his 120 vs 90 degree line image.

But, some K boats were fitted with 4 blade screws, so what ever layout Bob has decided to depict will be fine in the end  ok2

Good work up to now Bob, keep on plugging away!

Ian
Title: Re: Resurrecting the K Class
Post by: Colin Bishop on March 06, 2017, 07:27:45 pm
Sorry Ian, but if you look at the image in the link I posted it quite clearly says K4 on the conning tower and there is an unmistakeable 4 bladed prop hanging off the port shaft! I have copied the image below.

Most Ks were 3 bladers I think but K4 when she went aground had 4 bladers.

Colin
Title: Re: Resurrecting the K Class
Post by: Ian K on March 06, 2017, 08:26:37 pm
Hi Colin,

Nothing to apologise for!

I was basing my observation purely on the image Bob posted and the blade center angle comments from Subculture.

A friend of mine, scratch built a K boat at 1/48th scale many years ago. From builders drawings, It featured all the working gubbins such as retractable funnels, guns and vent shutters etc. It was a big beast!

I wish I could find the old 35mm film prints I took of it, when he exhibited at the Blackpool Tower show, in the circus ring pool back in the old days.

Ian
Title: Re: Resurrecting the K Class
Post by: Subculture on March 06, 2017, 09:06:44 pm
I would say you need to look more closely at that picture Colin. It hasn't modified my point of view in the least. The second blade is partially submerged in the water, in the same position as the shot taken from astern. When you offer up a 90 degree angle to it, the centre of the second blade is not inline.

I'm not going to waste my time posting up more pictures to support my opinion, as they just get deleted.
Title: Re: Resurrecting the K Class
Post by: Martin (Admin) on March 06, 2017, 09:26:00 pm


Tell you what Bob, put a three blader on one side and a four on the other!   ok2
Title: Re: Resurrecting the K Class
Post by: Bob K on March 06, 2017, 09:41:22 pm
Thanks Martin    {-)  {-)  {-)

People are welcome to their opinion, but stating it once is more than sufficient.

In my view, and it is my build, the rounded four blade propeller is totally different to the more pointed three blade of the wreck of K17.   The photo is not at right angles to the keel so superimposing lines can only be subjective.

(http://i1143.photobucket.com/albums/n626/bobkiralfy/K%20Class/4%20blades_zpseyi3kfsb.jpg) (http://s1143.photobucket.com/user/bobkiralfy/media/K%20Class/4%20blades_zpseyi3kfsb.jpg.html)

We can agree to differ, but in my view it is clearly a four bladed propeller.

Can we please move on.  I am making some good progress on installing the telescopic shafts.
 
Title: Re: Resurrecting the K Class
Post by: unbuiltnautilus on March 06, 2017, 10:08:40 pm
I have had a similar issue with the SS Ohio build. I am in opposition to ALL other models built of the wartime conversion to Ohio, and any sketches showing the bridge details, and I guarantee you I am right. We know our specific model better than anybody else ( unless they have built one also! ), and are sure of all the details...but should be open to all alternatives, just in case some new evidence comes to light. I have about eight photos of Ohio as converted..the odd image has started to surface thanks to the Imperial War Museums Archive becoming available on line, but nothing helping me find two rogue 20mm Oerlikons..


Good luck with the build, stick to your guns but always keep an open mind :-))
Title: Re: Resurrecting the K Class
Post by: Dr.Schmidt on March 07, 2017, 08:47:39 am
The nice thing about props is, that they usually come with a threaded hole, which makes them exchangeable, e.g. from 3 to 4 or the other way around.......just as a hint. 
Title: Re: Resurrecting the K Class
Post by: Ian K on March 07, 2017, 05:56:46 pm
Hi,

Just a technical blurb link to the K class boats.......

http://www.histarmar.com.ar/InfGral/SubmarinosK/(1915%20-%201931)%20K%20&%20K26%20Class.htm

It may help, if you have not got this info.

Ian

Edit:
(https://i.imgbox.com/UvXuK14S.jpg) (http://imgbox.com/UvXuK14S)
Title: Re: Resurrecting the K Class - Shafts
Post by: Bob K on March 08, 2017, 04:15:24 pm
HMS K9.  Shafts

I am trying to replicate the square telescopic prop shaft couplers ingeniously used by ‘Albion’, although with less space to play with.  Cut the nylon dog-bone couplers in half, cut square flats so they fit in the square brass tubes, then drill and tap for size 0 x 6.4mm stainless s/tap screws.  I sourced just the right sized stainless springs from inside Biro’s.  One square shaft slides over the other making 50 mm from dog-bone pin to pin with the spring compressed 30%. 

The purpose of this is to ensure a pressured ‘rattle free’ connection, yet allowing enough latitude to remove the dive module. 

(http://i1143.photobucket.com/albums/n626/bobkiralfy/K%20Class/couplers-1_zps3aaahckc.jpg) (http://s1143.photobucket.com/user/bobkiralfy/media/K%20Class/couplers-1_zps3aaahckc.jpg.html)

Next I can start to install the fixed prop shafts in the lower hull.  There is a slight angle, and I have used the coupler shafts to equalise the angle, half on each dog-bone.  The shafts pass through the hull at a very shallow angle so long slots were needed.  A temporary jig was made to adjust/set the positions of the shafts.   The shafts and tubes can then be shortened to the correct length. 

(http://i1143.photobucket.com/albums/n626/bobkiralfy/K%20Class/couplers-2_zpsxmpzxthu.jpg) (http://s1143.photobucket.com/user/bobkiralfy/media/K%20Class/couplers-2_zpsxmpzxthu.jpg.html)
Using jig to finalise positions of shafts before setting in hull.

Quite a bit more work to do before finalising shaft positions, but you can see my method.
Slots need lengthening even more, but am starting to get alignments nearer to ideal.  Prop shafts in surface warships are a whole lot easier.   O0


PS:  Generic information on a class built across seven shipyards is useful, but not definitive of specific ships.  Although based on Vickers drawings each yard utilised their own techniques and parts.
Title: Re: Resurrecting the K Class
Post by: derekwarner on March 08, 2017, 10:46:28 pm
Bob...being a Plan view, this hull space appears to be a free flooding water compartment when the K Class is submerged?...... would the compartment also be water filled/partially filled when the submarine was on the surface? ........Derek
Title: Re: Resurrecting the K Class
Post by: Bob K on March 09, 2017, 07:49:29 am
Derek:  All shaft components outside the sealed dive module are at the bottom of the hull and would therefore be under water even when surfaced.  I appreciate the need for waterproof grease and very frequent maintenance under these conditions.  I have seen a similar system used so it should work.

I am determined to complete this vessel and get it on the water.  Minimum goal is to have it surface running, but static diving if I can get it properly balanced and ballasted. 
Title: Re: Resurrecting the K Class
Post by: Albion on March 09, 2017, 08:52:07 am
The compressible drive shafts idea should be credited to David Merriman of Sub Driver fame, i just used square section brass to avoid the need for drive pins.




See attached recreation of the infamous photo, looks nothing like the real thing :(
Title: Re: Resurrecting the K Class
Post by: Davy1 on March 09, 2017, 09:24:53 am
Hi Bob,

I wouldn't worry too much about maintenance (greasing etc) of your prop shafts.

By their nature model subs spend far more time out of water than in it. Make things so that water drains out and they can dry.

David

Title: Re: Resurrecting the K Class
Post by: Bob K on March 09, 2017, 09:43:14 am
David:  Good advice.  I have a big slot directly under that end of the dive module, in the keel.

Albion:  If it was David who first created this drive system, fair enough.  At least it shows I am using the intended methodology  :-))
However with so many joints it is proving to be hard to get everything to line up properly

It beats me why people cannot clearly see the propeller blades in that photo, they are quite distinct.  When I have my drive shafts and rudder installed I will post a photo for comparison. 

I will not build the rudder and rudder support 'keel' until I have the shafts set, then the shaft supports last.
My shafts look a bit oversize externally, but that can't be helped.
Title: Re: Resurrecting the K Class - Shafts
Post by: Bob K on March 13, 2017, 02:53:09 pm
HMS K9.  Shafts

It took quite a bit of fiddling, and keep lengthening the slots to eventually become 90 mm long, such was the shallow angle through the GRP hull. 
I had to make a jig under the stern to position the shaft ends, and use some temporary Plastruct “U” channel forward to equalise the dog-bone joint angles as much as possible.  To avoid having the spring end floats to contend with as well I temporarily replaced the internal springs with plastic rod.
The parallel motors are on 25 mm pitch, and the shaft ends at 38 mm pitch.

(http://i1143.photobucket.com/albums/n626/bobkiralfy/K%20Class/shafts-jig-1_zpsqmvfrkrg.jpg) (http://s1143.photobucket.com/user/bobkiralfy/media/K%20Class/shafts-jig-1_zpsqmvfrkrg.jpg.html)

Now I can secure the shaft outers in the hull with f/glass resin and matting.  The outer exit profile will need pre-shaping with Milliput before matting in.  It will not be possible to recreate the original exposed shaft arrangement due to the position of the dive module and sprung telescopic connectors leaving almost all the shaft outers outside the hull.

When this part is completed I will make up the rudder and skeg keel extension.  The rudder is almost at the end of the slender ‘duck tail’ stern. 
As I can’t fit an appropriate mixer I am tempted to make the rudder oversize to improve its natural poor turning circle. 

Title: Re: Resurrecting the K Class - Progress & Milliput
Post by: Bob K on March 18, 2017, 11:08:46 am
Progress

Please appreciate that this submarine is not a “kit”.  I am fitting a dive module into a unique GRP hull, so just about everything apart from the module and GRP mouldings will be virtually scratch.  On top of which my experience in submarines is limited.
There are two subs at our club, a thunder tiger and an OTW Upholder Class.  The later is very impressive and I am grateful to its owner for helping me understand how it goes together.  Having an SLA battery in the flooded bow seems a neat idea.  On Sunday he showed me how the numerous linkages worked, something I need to design / machine / silver solder next.
BTW: OTW do a massive French Surcouf submarine cruiser, and an X craft.  Both over fifteen hundred quid, but very nicely engineered.

Milliput problems

Having secured the prop shafts in place with f/glass matting and car body filler inside.  All I had to do was create a smooth exterior contour.  Normally Milliput is just the job.  Can be worked with the fingers, smoothed with water, and can be sanded in about three hours. I have used it on many occasions before.
However !    Despite buying a new pack, and carefully kneading equal parts until even colour, after four days it was still rubbery and impossible to sand. 
I can only assume it had been on the shelf too long.  It happens.
So, picked out most of the Milliput with a screwdriver and rebuilt the external curves with Z-Poxy resin and fine matting.

Finally, I am now building the shaft end supports with soldered brass tubes. 
Title: Re: Resurrecting the K Class
Post by: ballastanksian on March 18, 2017, 05:06:32 pm
Sounds like a dodgy batch to me Bob. I have bought a couple of packs from model shops before now that perhaps did not get much passing trade for epoxy putties.
I found that while they did go off, the dark (I use the grey/yellow variety) part had a resiny skin on it and was quite hard, while the yellow part was very slimy and, as a result, did not want to mix with the other part even if that was warmed to soften.

I expect through our hobby carreers, we will all buy one pack of dodgy putty and it will always cause much grief.

Title: Re: Resurrecting the K Class
Post by: Bob K on March 18, 2017, 06:26:45 pm
It did feel a little dry and a bit harder to knead.  There is no sell-by date, so as you say it depends how much of it they sell over time.  The only loss was a week of build progress. 

Now I am working on how to construct the various control linkages, for rudder and two sets of dive planes. 
The rudder is in a really awkward corner at the tip of the duck tail stern.  Difficult to access.
I have bought a small pillar drill and a hand vice for it.  I am looking for brass bar of various diameters that I can drill through for rods, and use grub screws to secure.  Actuator arms will need to be silver soldered.
Control planes need to be in thin brass with soldered-in rods.  I will be making the rudder oversized as there is not enough space to fit twin ESC's and a mixer.  I still expect the turning circle to be substantial.
Title: Re: Resurrecting the K Class
Post by: ballastanksian on March 19, 2017, 10:15:53 pm
Given the difficulty of access and the inherrent need to get it right and well set up so as to be almost maintenance free, I would try and mark the rudder mechanism so that at a certain point the rudder will be in a certain position so that if needed you would be confident that poking the right tools in the right places would allow you to remove it should damage occur beyond that which you designed redundancy for in the system. A bit like marking the timing pulleys on an engine when removing the head to repair an overhead cam etc.

Repeated testing of systems both in and out of the water will reduce the need for repair or modification of course as you well know from your efforts on Poly.

Re Putty, I am not sure where you are best going to for fresh Milliput as places like Hobbycarft may hold stocks for as long as a small model shop if the local clientel are unaware of said product. I would hope that most model shops/online stores have enough modellers who know about it to keep the stock and thus the freshness turning over.
Title: Re: Resurrecting the K Class
Post by: mountfleet on March 26, 2017, 09:11:26 pm
Hi bob,
 I had independent motors on my big K to start with, expecting a huge turning circle but I was pleasantly suppressed. I think it was a better than the original rudder angle.
 I'll get some photos of how I did the funnels, but a word of warning, on the bench great but after a couple of dips the gremlins start.
 Also the mould for your K class is now with me.
 Adam
Title: Re: Resurrecting the K Class
Post by: Bob K on March 26, 2017, 10:25:01 pm
Thank you Adam.  Interesting about the motors and turning circle.  I was worried about that.
Anything you have on how you did the funnels would be most helpful.  I am aware that such immersed linkages will need a lot of maintenance.  Where I bought my hill mouldings, they no longer list them.  So, Mountfleet now have the mould !

ballastanksian:  I am waiting for the brass bars I ordered to arrive before starting on the linkages.  Space inside for the rudder actuator is tight, but I believe there is enough space -  Just.  Using grub screws will help access.
On the Milliput.  I have since bought a pack of 'standard' from the same model shop as the 'white'.  It worked fine, solid as a stone after 3 hours.  I asked them to check their stock of 'white'.  Open the box and give the rolls a gentle squeeze should show any that might be iffy.  My new 'standard' was super soft when gently squeezed.
Title: Re: Resurrecting the K Class
Post by: ballastanksian on March 26, 2017, 11:39:48 pm
In a warm environment (normal warm, not tropical!) it should be like this, and easy thus to mix together with the fingers or a sculpting tool.

Like most resins, it will cure much quicker if put on a warm surface. If you have a very warm place then place the item with putty on a piece of wood first to absorb the worst of the heat. I used to put work in my car's dashboard on a hot day and it would cure in an hour.
Title: Re: Resurrecting the K Class
Post by: Bob K on March 27, 2017, 08:37:06 am
My workshop is indoors. It was stored at used at normal room temperature.  Fine for previous and subsequent batches, but that particular box came quite dry and harder to knead.  I put it down to shelf life prior to purchase.
Title: Re: Resurrecting the K Class
Post by: mountfleet on March 30, 2017, 06:40:58 pm
Waterproof servo to do the funnel fold mechanism. If you look at the top casing, I had to made two lockers to go over the mechanism.
Title: Re: Resurrecting the K Class
Post by: mountfleet on March 30, 2017, 06:44:15 pm

This shows the x deans K modelling and as far I have got against my big 1:48 K.
Title: Re: Resurrecting the K Class
Post by: mountfleet on March 30, 2017, 06:46:08 pm
For size 3148th subs K class, E class and C class. This just shows the size of the beast.
Title: Re: Resurrecting the K Class
Post by: ballastanksian on March 30, 2017, 08:46:05 pm
That is a clever mechanism gentleman of Mountfleet. She was a giant and must have compared favourably with WW2 subs sizewise?
Title: Re: Resurrecting the K Class
Post by: Bob K on March 30, 2017, 10:19:48 pm
That is a very neat mechanism "Mountfleet", both in design and application.  Not just the funnels but the funnel hatches too.
At 1/48 scale that is one big beast.  I thought mine was long at 1/96.  I would be very interested in knowing what dive system you have on board.  Mine (only 43 inches long) I had problems getting a system small enough in diameter to fit.
I believe the size of the K's were not surpassed until the later days of WW2.

My build is still waiting for some special brass bar stock for the control linkages.  Been waiting three weeks, from a UK stockist too - not China !!  I am now assured it will arrive by Tuesday.  In the mean time I have a set of three guns for her from J R Haynes.  Nice quality.  The bases for two of them are moulded plastic for lightness.
Title: Re: Resurrecting the K Class - Drills
Post by: Bob K on April 09, 2017, 01:40:49 pm
Drills

Well, the special brass bars finally arrived.  I can now move towards making up the various plane and rudder linkages.  One problem was having to interface with some (US) Imperial sizes.  A lot of Googling showed Metric small drills seem to be limited to 0.5 mm diameter differences.  Ideally I need 2.4 and 2.8 diameters.  Coming back from a fruitless trip to B&Q I dropped into my local hardware shop, who often stock things the big stores don’t.  They also stocked 1.0 to 3.0 in 0.5 increments. Then he took out the famous Zeus book and asked if I had considered Imperial sizes?

Doh !   No, I hadn’t thought of that.  I came away with two each of 3/32” and 7/64”.  Just what I needed.  I have since ordered a 13 piece set from 1/16 upwards in 1/64 increments.  That should cover future eventualities.

Rudder will be an expoxied-in bush with a grub-screwed bush and soldered actuator arm.  Each twin dive plane set will have expoxied-in sleeves plus a drilled sleeve with grub screw at each end and soldered arm.
Title: Re: Resurrecting the K Class
Post by: Rob47 on May 09, 2017, 07:50:35 pm

Done bit of googling and you tube seems most sources say twin 3 blade props 7ft 9ins in dia,


Bob
Title: Re: Resurrecting the K Class
Post by: Bob K on May 09, 2017, 09:34:49 pm
More than twenty were built across eight separate shipyards.  There were naturally many detail differences according to where and when they were built, plus later in-service refits.  The only photograph of an actual K class propeller is of HMS K4, built at Vickers in Barrow-in-Furness.
I am building HMS K9 which was also built at the same shipyard so it is reasonable to accept that K9 had similar propellers to K4.  Four bladed.

Progress (or lack of it.)
At present I am struggling a bit on constructing the dive plane mountings, not having a decent lathe, milling machine, or pillar drill.  The solution I am working on uses imperial sized rods and tubes, the brass section from a 10A terminal block, and some very careful soldering.  More later, but it is taking time and care to make it both solidly practical and also able to be disassembled for serving.
The rudder and servo mounting should be more straightforward.  After that will come setting up magnetic couplings for the various servo rods.
Title: Re: Resurrecting the K Class
Post by: Akira on May 10, 2017, 01:07:26 pm
Bob,
 Your build is wonderful. Hat's off to you for tackling such a challenging project.
Jonathan
Title: Re: Resurrecting the K Class - Dive planes
Post by: Bob K on May 12, 2017, 11:24:20 am
Dive Planes

A frustrating situation causes delays whilst I figure out ways around the dilemma.
I know how to achieve what I want with these control surface fittings, and even served a five year apprenticeship as a toolmaker, but not having access to a lathe, milling machine, or decent bench pillar drill negates everything I knew.  I am constrained to improvise a solution using basic hand tools. 

Two inch long 5/16” dia solid brass bars with grub screws would be far too heavy. 

So donning the Bagpuss Thinking Cap I eventually formed a solution I could produce with the tools I have.  For the present I am utilising the resin cast planes with 3/32 brass rods.  The rods on them are too short for my purpose, so I extended them with K&S 3/32 rod and a 1/8 O/D sleeve, both soldered.  A short section of the next size up K&S tube forms the hull bearing.

Now the natty bit.  Cutting up a small terminal block I have a brass block with two screws to clamp the extended rod. The other end of the block was drilled 2 mm deep to suit 5/32 tube, and soldered to the tube.
Hurrah for Carr’s 188 solder paint, less heating and solder only goes where you paint it.
Finally, a brass actuator arm soldered to the central tube.  Total weight including planes 11 gm, and dismountable for servicing by just undoing the screws

(http://i1143.photobucket.com/albums/n626/bobkiralfy/K%20Class/dive-planes-1_zpsm4omj8sc.jpg) (http://s1143.photobucket.com/user/bobkiralfy/media/K%20Class/dive-planes-1_zpsm4omj8sc.jpg.html)

The above was assembled into the hull, securing the bearings with epoxy.

(http://i1143.photobucket.com/albums/n626/bobkiralfy/K%20Class/dive-planes-2_zpsp9p8duu9.jpg) (http://s1143.photobucket.com/user/bobkiralfy/media/K%20Class/dive-planes-2_zpsp9p8duu9.jpg.html)

Very restricted space, so the soldering had to be accurate. 

Next is the pair of aft dive planes, in an even narrower section of hull.  I had to adapt the above method so the rods meet in the middle with half circle flats, using a single larger terminal block to clamp both rods together.  Brass actuator arm solder to end of terminal block.

Pictures of that later, plus the relatively more simple rudder mounting and arm.
Title: Re: Resurrecting the K Class
Post by: Akira on May 12, 2017, 12:13:33 pm
Dive planes: very nicely done. I used a  sililar system on my large Seawolf. I soldered K&S square telescoping tubing, it was sized to fit the ID of the round "bearing" tubing fixed to the hull, to the plane's round shaft. I did this with the two dive planes off the hull and aligned so that when fitted to the hull they aligned. Then added a bell crank and was set to go. Great to see other's solutions to problems.
Are your "water proof" servos that you are using to raise/lower your funnels in the free flood area or in H2O proof containers? I ask because so many such servos are really only H@O resistant and will not resist repeated submerging to depth. Might be something to consider.
Beatiful work.
Jonathan
Title: Re: Resurrecting the K Class
Post by: Bob K on May 12, 2017, 12:25:52 pm
Thank you Jonathan.  I was impressed by that "wet" servo controlled funnels system, but I have a servo inside the dive module for that, but have not yet thought too much on how to operate them.
However, everyone has been telling me not to bother and to concentrate on getting the sub to work instead. 
Diving with the funnels up will look as ludicrous as running on the surface with them retracted though . . .
Title: Re: Resurrecting the K Class
Post by: ballastanksian on May 12, 2017, 10:59:42 pm
How about using small floats linked to the funnels that move up as the sub dives folding down the funnels. Using the water vents would allow them to fold the funnels before the sub has fully dived so making it look good but without electrical components to get wet.

This is a spur of the moment idea and I may be talking gibberish!