Model Boat Mayhem

Please login or register.

Login with username, password and session length.
Pages: [1] 2   Go Down

Author Topic: Gry Maritha  (Read 7314 times)

wombat

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 642
  • The view from the shallow end of the gene pool
Gry Maritha
« on: July 29, 2007, 10:11:33 PM »

Welcome to the new build....

No piccies yet, but I'm sure there will be fairly soon.

The work so far is to cut out the portholes and freeing ports in the hull and mount the rudder supports and the propshafts and "A" frames. Some problems there which I will document.

The plan is to make this bells and whistles all through - bow thruster, stern thruster, working crane, working fire monitor (though squirting water, not foam), working deck cargo-hatch. I am also toying with making the side hatch open. Hmmm, counting up the servo channels....

Bow Thruster - 1
Stern Thruster - 1
Motors  - 2
Rudder  - 1
Hatches - 2 Relay
Crane  - 2 + 1 Relay
Monitor - 1 + 1 Relay
Lights - 1 Relay

Hmm so that is 9 proportional channels and 5 relay channels. Going to need a bigger RC set - what I am planning doing is doing a PIC based custom control system for the auxiliaries, possibly running on a 433MHz link, which would allow for some telemetry. Quite a big job then.

Wom
Logged
The prat in the hat - www.floatingwombat.me.uk - Have look & say Hi

slewis

  • Guest
Re: Gry Maritha
« Reply #1 on: July 29, 2007, 10:16:30 PM »

Hmmmmmm   you dont like it quick and easy then ?  :D :D :D
Logged

Tug-Kenny

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 7,671
  • Location: Newport. S Wales
Re: Gry Maritha
« Reply #2 on: July 29, 2007, 10:28:07 PM »


We'll be on the bank, cheering you on.

Never one to sit still, eh Tim !!.    Sounds interesting.


Cheers...Ken
Logged
Despite the high cost of living   .......... It remains popular

wombat

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 642
  • The view from the shallow end of the gene pool
Re: Gry Maritha
« Reply #3 on: July 29, 2007, 10:31:48 PM »

On recent performance, I better fit it with dive planes as well.

Biggest disappointment on the Highlander was it only took 5 months to build

This is a longer term project. I'm not expecting it to be hitting the water within the next 12 months. Got two other boats to play with and a speedboat in build.

Wom


Logged
The prat in the hat - www.floatingwombat.me.uk - Have look & say Hi

slewis

  • Guest
Re: Gry Maritha
« Reply #4 on: July 29, 2007, 10:35:32 PM »

I for one am looking forward to this build and make sure you chuck loads of pics up as you go !
Best of luck with it .

Shane
Logged

wombat

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 642
  • The view from the shallow end of the gene pool
Re: Gry Maritha
« Reply #5 on: August 04, 2007, 09:05:58 PM »

OK here are some piccies......

Need to get the web-site updated, but got mugged by the week!!.

OK, so now I have got the bow-thruster, stern thruster and the motor mounts in. There is loads of filler on the inside of the bow-thruster to stabilise the hull - otherwise it flexes when you are trying to sand everything in andcracks away - mutter mutter. The motor mounts took a bit of aligning to get the shafts aligned with the motor so the coupling is straight. Got it spot on with one, the other shifted while the epoxy dried and needs  shim of 0.5mm styrene on one side.

Most of the fairing in is done - just need to finish up and get ready for spray.

Wom

Logged
The prat in the hat - www.floatingwombat.me.uk - Have look & say Hi

Channel

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 141
    • Channel Images
Re: Gry Maritha
« Reply #6 on: August 05, 2007, 02:41:49 PM »

This is a very nice model, I built one a few years ago. I know the real ship very well hense my interest in the model.

Colour changed a bit in recent years, she now has cream deckhouses aft with large company logo on the outboard sides. For a number of years she had a light blue hull but its now back to mid blue. Crane cab now green too  :-\

Logged
Follow my blog - www.channelimages.com

wombat

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 642
  • The view from the shallow end of the gene pool
Re: Gry Maritha
« Reply #7 on: September 16, 2007, 09:33:20 PM »

A long time since I posted on this thread.....not too much has happened on the old tub - I have chopped out the door in the side ready for the opening mechanism. The bottom is painted and the rear decks are on the way to being installed. What I have focussed on though is the fit out of the running gear.

Here are the platforms for the main electrics - the distribution board is a prototype ACTion P92 (coming soon to all good leather jackets near you), hopefully to be replaced by a pukka one. The cabling is there for the motors, just got to settle onthe motor controllers......HMMMMMM, I'm thinking something that gives a certian amount of action.

The Bow and Stern thrusters will be run off a single custom controller so they operate locked together for either slew or traverse. I will set the controller up so it drops the 12V down to 7.2V to keep the thrusters happy. You can also see the reciever - not mounted, I am waiting for some Velcro so I can pop it out to change the crystal (Or I could just swap it for the Futaba in the Aziz)

Next stage is to get the decks in but not until the control gubbins are in.


Wom
Logged
The prat in the hat - www.floatingwombat.me.uk - Have look & say Hi

Voyager

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 820
Re: Gry Maritha
« Reply #8 on: September 16, 2007, 11:40:08 PM »

I wish i was that good with electronics ::) Envy aside, your model is lookin rather impressive i must say!
I'm gonna be keeping tabs on this one, with any luck i just might learn something...I'll start with something simple like changing a fuse first ;D

Keep up the good work ship mate!
Logged

Tug-Kenny

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 7,671
  • Location: Newport. S Wales
Re: Gry Maritha
« Reply #9 on: September 17, 2007, 11:24:05 AM »


Nice high freeboard on this model. I can see why it flexes when empty.

Looks like plenty of room for 'stuff' inside. Watching with interest Wom. Keep up the good work. It's so tidy. O0


Cheers...Ken


Logged
Despite the high cost of living   .......... It remains popular

BORIS

  • Guest
Re: Gry Maritha
« Reply #10 on: September 19, 2007, 09:30:38 PM »

Good choice of model there O0 i have made it myself but i only have the Bow Thruster ..and yes due to the angle of the Hull , it was a little awkward to  drill out the holes to fit etc..but you have done a decent job..i like your electrics ..you have much more cables etc than i do yet everything looks so neat..good luck with the rest of it and keep sending the pictures...ps "channel your model is diabolical!!! only joking I mean Great!! and yes you are right about the actuall boat being a Darker Blue..[i live in penzance] so if i could make it again [wombat] .i would use a darker colour blue.
Logged

Tug-Kenny

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 7,671
  • Location: Newport. S Wales
Re: Gry Maritha
« Reply #11 on: September 23, 2007, 09:04:09 PM »


I really like this model, and may well be buying it soon.     O0

Have done a bit of research and find there was a write up in Marine Modelling in April and June of 1995. The June edition is now out of print, so no point in getting just the April copy.  Does anyone have these 'Mags' and could possibly let me have , either the originals or perhaps photocopies. I will gladly pay my way.   :)

Perhaps Wom would be interested as well.


Cheers...Ken


Logged
Despite the high cost of living   .......... It remains popular

wombat

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 642
  • The view from the shallow end of the gene pool
Re: Gry Maritha
« Reply #12 on: October 06, 2007, 08:52:04 PM »

Lots of nice comments there  :embarrassed:

The thing about the Gry is that it is totally asymmetric. Though it is a bit slab sided - striking (read ugly) rather than elegant.  Progress continues to be slow, mainly because I have been spending time on the two black boxes on the sides of the equipment platform. SWMBO has been moaning I have spent too much time on them. Basically they are a pair of ACTion style ESCs. OK I admit it, more prototypes for FLJ - this time the P93 Multicontroller - they just need a few more tweaks to get them spot on. Also a quick sneaky-peak at what goes on inside.

The blank black box is placeholder - for the Bow/Stern thruster controller that I need to cook up. Basically two ESCs in a box controlled off a single channel. Toggling the stick to one end or another sets the thrusters to run either in the same direction or opposite directions - which give either traverse or rotate. Need to get this done before the decks go in, though I may take a break from electronics and get some of the building done.

The reciver is mounted up on its side on velcro because of cable length limitations on the servo cables - the velcro means I can lift it off the support to change the crystal, because when the decks are in accesss is limited - as it is, I will have to make a false base for the main hatch area so it can be lifted out to give access to the battery.

Building the model ahas thrown acouple of problems, I don't think the documentation is as good as the Aziz - for instance I have built my own deck reinforcements before finding the parts required on parge two of the plans - if they were mentioned in the manual I missed it.  Never mind eh!

Also got to start thinking about how to do the crane and hatch controls  - for the winching operations, I am thinking of doctored servos - so they become more like ESC/motor sets. Similar to the article in the mags this month, but without removing them from the case. Shouldn't be too hardto butcher the S3003s to do this. Couple of PICs and things to provide the limit switching and control. But that is yet to come.

Voyager - I spend too much of my life on electronics - though now I am more hands-off at work these days. Part of the reason for doing this design is that I want to keep my hand in.

Kenny - I think that the room inside is deceptive - there is a reasonable amount, but it is getting eaten up. Also the front superstructure is not removable (as far as I can tell, so it will be difficult to use that space.

Boris - I will be painting it in the darker blue colour - witohut the large lables on the side as that look more attactive to me - I would like to see the real ship, but Penzance is a bit of a trek for me. I will have ot do with photos - though I would like ot get my hands on a decent copy of the owners logo for the side. I do like tidy electrics - it does make fault finding so much easier. I think also that it helps the reliability - though I get through ty-raps and cable tie bases like they are going out of fashion. I am using Crimp pins and bootlace ferrules on this model because of the large number of screw terminals  - they really do make life easier and avoids thep roblem of leads pulling out. (Note to self - piut the ferrules onot the p92 connections)

Wom

Logged
The prat in the hat - www.floatingwombat.me.uk - Have look & say Hi

wombat

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 642
  • The view from the shallow end of the gene pool
Re: Gry Maritha
« Reply #13 on: December 16, 2007, 08:56:07 PM »

It is two an a half moths since my last confession.....

Not a lot of movement since then, or at least not a lot of visible movement. The main main change is that the hull electronics are completed - it has eveything to drive the boat through the water. Lots of ACTion stuff in there - all prototypes I'm afraid. The drive motors are driven using P93 ESCs - incidentally, these have been updated to support limit switching, ideal for winches on those thug-tugs. Nestling between them is a prototype of the Bow/Stern thruster controller - basically it is a dual esc whic will run as a dual ESC, an integrated ESC/Mixer or the mode I am using - which is for the thrusters. One stick is used to control the thruster speed, blipping the rudder when the thruster control is on neutral makes the thrusters drive in opposite directions (Spinning) or in the same direction (traverse).

The crane is built up and most of the detailing is done hough the paintork needs touching up a bit and a few details need to be painted in. I have the mechanism for spinning the crane and raising and lowering the jib. There is a stub on the drive motor which will be used for a potentiometer used to position the boom -  particularly for limit switching, though it will be used for parking the boom. The raise/lower is driven by a servo. The litle bit of wire you can seen hanging is for the hook cable - though whether I will actually use it is a bit moot at the moment - ideally it would have routed down the raise/lower control shaft but I didn't have any handy - it should be OK as long as the boom isn't allowed to swing too far.

Wom
Logged
The prat in the hat - www.floatingwombat.me.uk - Have look & say Hi

pops

  • Guest
Re: Gry Maritha
« Reply #14 on: December 18, 2007, 12:40:48 AM »

Very nice work wombat. I especially like the neatness inside the hull. It's hidden to most people and many overlook this area. I like that you have put a neatness priority in it. Great thread, look forward to seeing more of it.
Logged

bosun

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 379
  • Location: NEWPORT SOUTH WALES
    • bosunsmodelboats.com
Re: Gry Maritha
« Reply #15 on: December 18, 2007, 10:19:41 AM »

Hy Wombat,
I am really impressed with your build, its looking great...one question,,,, (maybe a bit of a daft one) on the pic number 2628, there is what looks like a screw on the end of the ariel wire, is there a specific reason for this ?, or am I mistaken.
Thanks
Bosun
Logged
bosunsmodelboats.com

wombat

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 642
  • The view from the shallow end of the gene pool
Re: Gry Maritha
« Reply #16 on: December 19, 2007, 10:27:27 PM »

Hi Guys,

Pops, I put great store by tidy wiring - it is more reliable, easier to fault-find and easier to modify than the rats-nests that you see all too often. Then again, my background is in things like HV systems and Evacuation systems (and a little bit of hazardous area work) so I have been trained in the right way to wire things up. Also the inside should look as good as possible - after all you have to look at it every time you take the top off the boat. I was toying with painting the inside, but then I had a lie down and felt better. Note to self: must sort socks by age, colour and size of hole.

Bosun,

the screw on the end of the aerial lead is for the external aerial - it pushes into a moulding mounted on the deck and the aerial wire screws into it. The mounting will be disguised as a bit of cargo, then when I am sailing I just screw on the aerial. Here are the details....

http://www.jperkinsdistribution.co.uk/detail.php?JPNO=5511775&activepage=1&Navmain=Marine&subcatname=Accessories%20marine

Wom
Logged
The prat in the hat - www.floatingwombat.me.uk - Have look & say Hi

Stavros

  • Guest
Re: Gry Maritha
« Reply #17 on: December 19, 2007, 10:53:19 PM »

Wombat I presume that the middle Black box is either a mixer or speed controller,dare I ask knowing your superior knowlage of electrics BUT wont you get interference having the receiver so close to it whatever it be!!!!

Stavros
Logged

wombat

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 642
  • The view from the shallow end of the gene pool
Re: Gry Maritha
« Reply #18 on: December 19, 2007, 11:33:37 PM »

Hi Stavros,

Right on both counts - it is actually 2 ESCs and a mixer in a box. And a good question...the effects of radiated emissions from the ESCs on the reciever will be relatively limited - the rise time of the FETs is around 150nS (equivalent to around 6.6MHz) so the main frequencies from the switching are well below the 40MHz. The big problem comes from the switcihng current spikes coming up the wiring into the reciever and upsetting the output logic. This is limited by separating the power wiring from the reciever wiring - these are bundled up and kept away from the power wiring - you can't see it clearly, but I will try to get some better pictures. Inside the ESCs I have resistors between the power ground and the reciever grounds to prevent ground loops, which are a real killer. All the power stars up at the P92 deistribution board so current pulses on one ESC cannot couple onto the others or onto the reciever.

All sounds a bit complicated but the principles I have used are basically:
1/.  Keep power and servo leads separate - if you are running for more than about 100mm, keep servo leads separate to prevent crosstalk
2/. Do not loop signals and power through multiple units, bring them to a common point - more wires but less interference
3/. Size the wires generously
4/. Run power and ground together rather than spearately - if you are really worried about noise twist them together though this can be overkill
5/. Suppress the motors well. I prefer 100nF to case, 220nF across motor terminals. Always use good quality disk ceramic capacitors with a 100V rating.

Wom
Logged
The prat in the hat - www.floatingwombat.me.uk - Have look & say Hi

kiteman1

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 177
  • Proud to be a part of the Model Boat Mayhem Forum.
Re: Gry Maritha
« Reply #19 on: December 20, 2007, 07:45:53 PM »

Hi Wombat

It's interesting to read about the effects of interference.  Would it make any difference if the power and radio wires were each wrapped in tinfoil and then run together down the length of the model?  Would this method cure any crosstalk?
Logged

wombat

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 642
  • The view from the shallow end of the gene pool
Re: Gry Maritha
« Reply #20 on: December 20, 2007, 08:38:19 PM »

Hi Kiteman,

Tinfoil would help to prevent crosstalk and interference, though you would have to make sure that the tinfoil is grounded at one end. Effectively this will screen any electric field interference. More effective yet is screen both sets of cables.

If it were me though, I would splash out on screened cable, particularly for the servo leads. The effort to get a good screen with tinfoil wrapping would be difficult. I would consider this to be a last ditch effort - you don't actually need that much space to get a reasonable reduction of interfeence. Down opposite sides of the hull would give a good separation. The interference reduces with the square of the separation - so if you double the space between the cables, you quarter the interferece.

Wom
Logged
The prat in the hat - www.floatingwombat.me.uk - Have look & say Hi

Stavros

  • Guest
Re: Gry Maritha
« Reply #21 on: December 20, 2007, 10:30:00 PM »

Thanks for that Wombat I knew there was a simple reason behind your logic

Stavros
Logged

wombat

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 642
  • The view from the shallow end of the gene pool
Re: Gry Maritha
« Reply #22 on: December 21, 2007, 03:28:35 PM »

Here is a close up of the Radio wiring - I am using the BEC on the P92 which is fed into the P94 mixer/ESC then out to the other ESCs and the rudder servo

Wom
Logged
The prat in the hat - www.floatingwombat.me.uk - Have look & say Hi

wombat

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 642
  • The view from the shallow end of the gene pool
Re: Gry Maritha
« Reply #23 on: April 08, 2008, 10:27:58 PM »

Hi All,

Well here are the latest updates. The foredeck is in - put the deck in level with the rear decks as I understood the instructions - this is also at the same height of the superstructure, but is about 3mm below the freeing ports. Probably wrong, but hey - don't think I can face changing it now.

I have ballasted it up so it sits level on the water - side to side and front to back. I will probably have to be back out with the level once the superstructure is in - I guess the crane will imbalance it. The electrics have been totally redone - all the motors are now protected by P95s with appropriatly graded fuses. The P94 is not debugged so all you people dying to get their sticky little maulers on them don't have long to wait - runs the thrusters a treat, but those graupner thrusters are really noisy. There is a little bit of a leak on them - maybe 5-10ml in two or three hours, nothing to worry about.

Next stage is to get the rear part of the deck in - will need to add in some spacers to get the right curve on the hull to match the superstructure. This needs to be painted up but it is complete.

The main hatch is done - a slight gap to fix, but not a big problem. The split in the hatches is not quite right - the inner ones lift off the rails at the extremes and there is a lock up if you open it too far. Will have to limit the travel.

Wom
Logged
The prat in the hat - www.floatingwombat.me.uk - Have look & say Hi

wombat

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 642
  • The view from the shallow end of the gene pool
Re: Gry Maritha
« Reply #24 on: April 09, 2008, 07:19:35 PM »

AAAAAAARRRRRRRRGGGGGGGGHHHHHHHHH

Never ever write messages at bed time!!!!!!

It should read

The P94 is NOW debugged

The software is ready and tested and good to go!!!!!!!!!

Wom
Logged
The prat in the hat - www.floatingwombat.me.uk - Have look & say Hi
Pages: [1] 2   Go Up