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[Waiting2Retire]

Hi All,


I have been lurking for a while enjoying everyone's builds.


I have a boat that I was given as a child in the 80's, which I very much enjoyed sailing as a youngster (it was probably longer than I was tall at the time!) that I have always cherished and held onto and now need to show some TLC to as its not been on the water for... 30 years? And while stored in the dry its collected its fair share of dust.


The poor railings were always a struggle when new, the side ones repeatedly knocked off by the straps from the cradle, but over time whatever the string was doped in had tightened causing more damage and the manoeuvring in/out of the loft and moving house added its share of damage.


Still resplendent with its 27Mhz gear and 6V Hectoperm motor it needs a refit of running gear with something much more modern, as well as attention to the woodwork and finish.


The first question, and purpose of what I think is my first post, is does anyone recognise the hull/design/plan it was built from? It was built by a Great Uncle early 80's, the construction is all wood (which its weigh confirms) and it looks like its plank not sheet that make up the sides. I believe it to be scratch construction... but have no firm details.


Size is 138cm long, 32cm beam at the widest and around 28cm from base of hull to top of cabin (excluding the mast). If you want that in old money it's 54" long, just over 12" in beam and just under 12" from base of hull to top of the cabin.


Pictures worth a thousand words, so hopefully two attached if I followed the guide right!

[dougal99]

Loks to be very similar to Vic Smeeds Lorraine. Plan available here https://www.sarikhobbies.com/product/lorraine-mm512/

[Circlip]

You have a PM W2R.   


  Regards  Ian.

[Waiting2Retire]

Thanks both that’s brilliant 


Looks to be exactly the plan the model was built from, only had a chance to do a quick search tonight but looks like it was printed in April ‘58 model maker so not a new design!


I know it’s not the most exciting model, and not the most practical due to its size! But really looking forward to cleaning it up, repainting and getting new running gear into it.


First step, check it’s still water tight, one thing with the design is the front sections are sealed so no easy way to confirm no leaks other than an extended test in water with before/after weighing maybe?

[JimG]

No need to replace the Hectoperm motor just because its old, they are good motors and will keep running for ever as long as they get an occasional lubrication to the bearings. New motor may be flashier but not always better. This model looks like a river cruiser so wouldn't be that fast in full size, making it plane with a higher powered motor will just look wrong. As long as the bearings in the prop shaft as good without excessive wear and leaking this will also do the job, just lubricate them and perhaps add an oiling tube if it doesn't have one already. For this sort of model a sealed lead acid battery (gel cell) will do, no need for NiMh or LiPo packs as you will not be looking to reduce the weight for speed. Only the radio gear is really needing replaced as while 27MHz is still useable it is a frequency band with a lot of other users, simple 2.4GHz sets are cheaply available and a replacement rudder servo and speed controller easily obtained, no need for expensive high powered ones.
Jim

[Waiting2Retire]

Hi Jim,


Thanks for the feedback, you are of course correct on all points, however it's not just a case of new and shiny as much as practicalities of using the model. I agree 100% it needs to motor around in a scale like fashion (tempted to build myself a Fairey later for more speed) but one issue is it never quite managed sensible performance back in the day. The model is pretty heavy even without the batteries fitted.


The original arrangement was twin 6V lead acid batteries, they were twin only to balance the weight is my recollection not as it needed two batteries, the original PCB wipe speed controller is mounted over the motor with the batteries in boxes either side as low as possible:

The motor is mounted under the speed controller, its marked 6v at 8A max so 48W by my calculation:



The boat was always very sluggish on the water, any sort of "motor cruising" required building up a head of steam - although its been 30 years since I last ran it so my memory may be clouded.


While I am rusty on the whole boating, I know enough that you can't talk propulsion without propellors, currently fitted is 3 blade prop that I think is around 42mm (probably imperial, inch and a half?):



And it seems quite deep as well:



So I always wondered if the prop was too large/heavy pitch for the motor's output, no idea what the RPM is but I have a optical tacho in my toolkit these days so I can measure that when I get a moment.


The drive coupling also needs a review/renew as it seems to be mechano based, and on one occasion lost drive and fortunately didn't become a permanent feature at Bushy Park on the central island (that was at least there in the 80's!).



The wire here on the prop shaft is earthed to the motor casing, there is no oiling tube, I seemed to recall grease/oil was done with a large syringe and the prop shaft removed, which is probably where young me messed up the coupling and had the free sail moment at Bushy.


I would like to add some and oiling tube so that's on the list of things to look into, not sure how that would happen with the prop shaft I already have fitted.


So all this combined gives the following:

• Always seemed underpowered
• Prop shaft needs oiler ideally and coupling reviewed
• The 6V SLA batteries degraded years ago, I removed them before boat was stored, and disposed of them a few years back as they were end of their life (have a decent charger, they could not be revived)
• I currently have a selection of 3S and 4S Lipo's from cars, planes and a tank on hand
• I need to fit a new speed controller anyway

Which is why I am thinking a new motor, I can get a suitable low Kv brushless and just buy a brushless ESC not a brushed one, I have no spare ESC at the moment so I have to buy one. Then I can use my 3S or 4S Lipo for power, probably I have to add ballast low down to compensate for the missing lead and get correct waterline and scale look.


I have been doing some reading last night as it happens, I think a 900Kv motor is going to provide plenty of torque and I can limit the throttle on the transmitter if it starts to look too fast.
I am not opposed to keeping the Hectoperm other than its underpowered, and to buy two new 6V SLA costs more than a new motor and mount - I have to buy an ESC either way.
Comments/experience on any of the above thinking more than welcome 
I have a transmitter used for other models, and should have spare receivers in stock, I might only have micro servo's but I will order up a full size rudder servo.


The original setup has all the radio gear in a box in the aft cabin, not sure I will retain that as it takes up a lot of room, you can see it through the windows (when I take out the yellow ones and put new clear ones in) and modern gear is a bit more robust and economical if the worst happens.



The servo's are so old they are actually made in Japan 


Lots to think about anyway...


Paul


(I don't know why when I leave one line, the forum makes two lines spacing, I also really hope once I do a few more posts I no longer have to give the kings inside leg measurement in future!)

[Circlip]

The 'Meccano' coupling is pin and disk drive and if you get the motor connection sorted is better than many of 'Todays' efforts. If the 'Bobs Board' (speed controller) eventually gives up the ghost you could replace if with a brush ESC type but as with everything, if it aint broke - - - . Had a similar prop on a Seaplane Tender, used to adjust the pitch, carefully, with a pair of pliers.


  Regards Ian.

[Waiting2Retire]

Hi Ian,


My original plan was just to use a brushed crawler ESC like a Hobbywing 1060, partly as I know they work well and partly as they are cheap, waterproof, have a cooling fan, and I have the programming card already.


I only started looking at the motor when I looked up how much those 6V sealed lead acid batteries are £30 each!
[size=78%]https://cpc.farnell.com/yuasa/np12-6/battery-lead-acid-6v-12ah/dp/BT02343?st=6v%20lead%20acid%20battery[/size]


Not sure I want to invest £60 in lead acid for a single use, when I can put in a new motor and use other batteries I have on hand.


I did have a thought after my large post earlier where I might have another 6V SLA battery in a big old torch, I will check that out later in case I can use it for testing at least. I also have a dual brushed ESC in a box for a tank project I can borrow to replace the Bobs Board - I have the packet/card header for that somewhere is their a market for "vintage"!


Paul

[barriew]

Check out Component shop. 6 volt SLAs for models from £5.95.


Barrie

[Waiting2Retire]

Check out Component shop. 6 volt SLAs for models from £5.95.

Barrie

Thanks Barrie, £13 for the 12AH 6V, £8.45 shipping is also not that bad for the weight!


I need to go rummage in the garage on lunch break to see if I can find the 6V SLA in something I think I have one in, then I can at least do a test with the motor (that it still runs, and RPM) before investing in SLA batteries to retain the existing running gear.

[chas]

In our club anyone who wants an sla battery goes to one of the shops selling house alarms. Good prices and no delivery charge. They're used for backup power in many alarms.

[roycv]

Hi what other batteries do you have?
If you have 6 cell NiMh batteries then use them.  If you have 2S lipo then use them.  The motor is not that fussy over an extra volt so it will not be a problem.

I use SLA's but only as weights for holding down wood being glued.  The SLA's may seem cheaper than the usual batteries but they are not.  The capacity of an SLA is measured differently as they are measured at a discharge rate over 20 hours.
So 6 volts and 12 Ah means you will get the full capacity of the battery if it discharged at a twentyth of stated capacity, which is  600mA.  0.6 amps x 20 = 12 (AH).

For a Nimh battery. which is measured at the 5 hour rate is 7,2 volts say 3000mAh, is 3000 divided by 5 = 600mAmps  so a 3 Ah battery and they cost about £15 and are lighter.  A quarter of the measured capacity of the SLA., but about the same energy capacity


With a Hectoperm motor using a Bob's board and that prop, it will need at least 3 amps and the battery will get hot as well.  If the battery gets hot this energy has come from the battery when it should be powering the motor.

Have a look at Nimh battery prices and see what you can afford.  In the past I have found that the max size packs are dearer than 2 cheaper packs that add up to the same capacity.  The larger the capacity of the drive battery the more efficiently it will run.

Cylindrical lead acid cells are measured at the 5 Ah rate and you can treat them as equivalent capacity to NiMh batteries.  Also unless you know better beware of buying what look like bargain Chinese  batteries, most have gone now but there still some being sold.  They often give a full spec  for them to impress you! 
However this also includes the weight of single cells, so if tempted note the weight and then check a reliable UK seller and see if the weights tie up with what is claimed.  The lower the weight the lower the capacity of the battery and this applies to all of them.

In the past, and this may not be for you, I have bought 2 new packs and run them in parallel charging them together and they have worked fine.  I know that there will be objections but have any objectors done it for themselves?

If you look at the new electric full size car technology there are lots of batteries running in parallel, so can't be all bad!  I have looked at a car replacement pack of LiFe cells and they seem to be connected directly to each other, no separate charging for each pack.  LiFe cells are each 3,6 volts.

Incidently if you have an old 27Mhtz transmitter with single battery insertion you will notice that modern AA cells are marginally bigger than the old batteries in use when the transmitter was new.  This may stop you from getting the security cover on

I still use these and 40 Mhtz sets and have recently found that you can fit 10 AAA batteries (800mAh) in a welded pack into the back of the old Tx's where the batteries are in a flat area.  You will need to solder wires into the Tx for + & - and a servo lead with a socket lead fitted to battery pack.  The higher voltage (12 volts) gives over 4 hours duration. 
Regards
Roy

[Circlip]

Wonder how many packs you can make from a Tesla with a broken dashboard? 


  Regards  Ian.

[Subculture]

For a Model S 3960 packs for 2s lithium.

That'll keep you running until teatime.

[Waiting2Retire]

Hi what other batteries do you have?
If you have 6 cell NiMh batteries then use them.  If you have 2S lipo then use them.  The motor is not that fussy over an extra volt so it will not be a problem.
...
Regards
Roy

Thanks Roy,


Especially for the tip on the Hectaperm being OK slightly over voltage, I have been thinking about how to regulate a 2S Lipo down to 6V for testing today, the 6v SLA I found was 2v and not responding to float charging - and any test water too far from my bench power supply! I will try a 2S pack at storage voltage and see what RPM I get as a baseline.


I have a couple for 2200mAh 3S, a 5000mAh 3S, some 3300mAh 4S (too much power!) and a couple of small <2000mAh 2S packs so I am leaning towards using 3S. These are all LiPo. I can run in parallel for double run time.


I have been doing some reading on prop speed (that's dark art it seems) and seems like with 10,000 RPM as a guide to max speed I need something brushless <900Kv on 3S and as its just a motor cruiser not a planning hull maybe 750Kv if I can find one.


Its a fair weight (plan to weigh it later, once I get through the DIY list for my superior...) so I am thinking a 3536 900Kv or something like that looks about right, I have been making a small list of what SLEC recommend and looking at what others on the forum are using. There is a 3548 790Kv as well that looks like it would have lots of torque but seems grossly overpower - although its 54" so don't want to do it twice and more power with the TX turned down is better than underpowered and replacing the motor twice. 2834 in 750Kv is the smallest option, 9,225RPM on 3S.


2824 750Kv (300w) gives 9,225 RPM on 3S
3536 900Kv (400w) gives 11,000 RPM on 3S
3548 790Kv (840w) gives 9,717 RPM on 3S


The first two would run on a 30A ESC, the big one would need a 60A ESC, but looking at the Hobbingwing car ESC (with fan rather than water cooling) the price difference is not that large between them.


Radio wise, I already have a 2.4Ghz TX so the 27Mhz gear can go to the museum...


If anyone has any suggestions/comparisons for similar sized hull and the motor options above I would welcome comment/opinion. Only thing ordered so far was a alloy motor mount to to see how it might replace the Hectaperm and need fixing.

[roycv]

Hi in general you can run a brushed motor at 50% above quoted voltage as long as you let the motor rev.With the prop yopu have my guess would be 1500 - 2000 rpm will give a good turn of speed.
Roy

[Circlip]

DON'T get rid of the Few barter, you may want to drive  a cheap Sub.


 Regards  Ian.

[Waiting2Retire]

Hi Ian - assume "Few Barter" = Futuba? 
I subscribe to the "the thing you throw away today is the thing you need tomorrow" mantra, so I was thinking of the museum in my garage loft when I said it can go to the museum 

[Waiting2Retire]

Hi in general you can run a brushed motor at 50% above quoted voltage as long as you let the motor rev.With the prop yopu have my guess would be 1500 - 2000 rpm will give a good turn of speed.
Roy

I will measure the no load RPM in a bit (now the blind is up  ), but if I only need 2000RPM on that prop then I need a really low Kv brushless and either a 2S pack or limit the throttle on the TX with 3S (advantage being less amps at the higher voltage - cheaper ESC).

[Circlip]

Yep, and with the lump of Red Rock in it, thanks to all the new Tech now leggy, there won't be a queue waiting for the peg.


  Regards  Ian.

[Waiting2Retire]

Ok time for some new calculations!


6v @1.08A - 2500 RPM
7v @1.02A - 3000 RPM


That's on the Hectoperm and I assume poor lubrication in the drive shaft (only ran for a few moments to get a reading), so a staggering 6.5W of power... I think I need to find something 500Kv and 2S only.


Without the SLA batteries she weights 10.3Kg/22.5lbs, the Vic Speed plans talk about 35lbs displacement, so 12.5lbs/5.7Kg lighter - not weighed a battery but they look about 2Kg online so 4Kg for the pair.

[roycv]

Hi my numbers are for in the water.  I had a similar size model and 2000 rpm on a 45mm prop used 30 Watts.  It was a light boat and planed on 30 Watts.  I made my own rev counter so readings were from that.

Oil should be used where necessary.
Regards
Roy

[Subculture]

Think I'd just pension off the Bob's board for a decent brushed ESC, new batteries and fit 2.4ghz receiver and leave it at that.

[Waiting2Retire]

Well my (very distant) recollection is that the Hectoperm was very underpowered which made for some tricky manoeuvring as you had limited ability to slow down once you finally wound up to a cruising speed.


If I need to buy a new ESC it can be either brushed or brushless, and a new brushless motor is cheaper than new lead acid batteries (I can re-use existing LiPo) so I am going that route.


I ordered a C2834 750Kv Surplus Outrunner, that's 300W so 19A max, but I am hoping the low Kv makes it torquey and I can limit the RPM with the TX. I wanted a Hobbywing ESC as I have the programming card already (1080 in a crawler) but they were coming out expensive so I went for a ZTW Shark 50A ESC as due to the incomprehensible discounts on Aliexpress it was £17 - good value if it works as advertised!

The smaller motor should also allow a cabin floor to be fitted which it doesn't have at the moment, and perhaps a nod to a few internal features like a wheel and a captain.

The superstructure looks like its made from 3mm (1/8") ply, I probably need to go look for threads on woods because I am wondering if modelling ply is superior to what is down the DIY store, not sure the cabin floor needs to be exotic as it will not really be seen... and I am sure the question has been asked repeatedly on the forum already!

[Waiting2Retire]

Right, bought a new rudder when at the local model shop in the week (yes there still is one!) and tried to fit it this morning, but it seems that the 40 year old one is imperial and the replacement is metric. I had hoped to retain the sleeve and just change the rudder and shaft.


It's interesting that the rudder is almost identical is size and shape, but the new rudder shaft is 4mm constant and is a tight fit into the existing brass tube in the hull. I measured the old shaft and its 3.6mm OD at the top but seems to tape to 3.2m OD near the rudder, its not clear if this is by design or its wear on the rudder shaft (seems unlikely the boat had enough use for that to be the case.


Now contemplating my options:

• Retain original shaft and repair the rudder (I bent it, then in panic checking the damage snapped the join) so as well as solder it would need a pin I think.
• Remove the original rudder sleeve tube and fit the modern plastic one.

I started on removing the original tube, removed some epoxy on the (imperial) nut and unwound it very slowly due to imperial socket not fitting over the exposed thread and having to use an adjustable spanner (no imperial spanners here).


The shaft is still firm, I am wondering if it's been glued into position, and now worried about causing damage trying to remove it. If it was metric I would lock two nuts on the thread and try to twist it a bit, but as it's imperial and I only have the one nut that's not going to work. Equally wary of using pliers and damaging the tube that then still can't be removed.


Going to sleep on the problem and look again in the morning...