I'm quite surprised to see a brushless motor specified for a scale boat. It's true that they have made massive advances in recent years, but I thought this was mainly for speed and power. As Ashley says, tell us the size of the model and you'll get some good opinions.

Chas

The model is 38 inches long which is quite large and the original boat had a speed of 25 knots so it will need a fair bit of power to push it along to give scale looking appearance which is why John Parker was emphatic that a brushless motor would get the most from it.

Should work fine with NiMH batteries though instead of the more expensive LiPos. John's model runs on 7.2v and performance looks good from the article photos.

Colin

Hello Peter,

Glad to hear that you are enjoying scratch-building from my plans.

You'll like the Picket Boat, it's a favourite of mine in operation and a straightforward build.

I first used a brushless motor in a scale boat many years ago, and never looked back. It's not just about power and speed, a low KV outrunner brushless motor will turn a large prop like the Picket Boat's very effectively without a gearbox. I've traded the harsh grinding of a gearbox for the turbine-like whine of a brushless motor and I think that alone is worthwhile, but it is the gain in efficiency that is most gratifying. I don't actually know how long the PB runs for on its two 7.2v NiMHs, because after two hours of zapping around I'm ready to go home! I estimate about 75-80% power provides scale top speed – it's always good to have a little extra in hand with a model. We are not unduly worried about weight with the round-bilge hull; I've tested the PB with the weight of an extra two batteries and it makes little difference to the performance.

You shouldn't have to spend a lot of money. Here in Australia not many hobby shops cater for boat models so I am more or less forced to buy on-line, and find that a brand-name brushless motor and ESC combination can be had for much the same price (or less) than a good brushed motor/ESC option (surplus specials excepted), certainly if you include the gearbox you'll likely need. Turnigy motors are OK, perhaps paired with an Mtronics or SJ controller if you don't trust the cheap Chinese ones.

That's my case for a brushless motor- but the main thing is, have fun.

Yabbie1 (John Parker)

Peter. A good point. I didn't know it until recently when I was purchasing such stuff for the next project, but you can get woven fibreglass cloth, as an alternative to chopped strand (the stuff you see in car shops) in very fine (like silk) up to quite thick grades.

​The big difference is that there is no binding agent in the woven stuff, so it looks and feels like cloth, and lays perfectly over hulls (for instance) even before being wetted with resin. It is the resin that melts the binding agent in chopped strand allowing it to become loose enough to get pushed about.

​You can also get (from specialist suppliers) slow cure resin, which takes up to 8 hours to go off, invaluable it seems to me as you can mix several batches to cover in one go and not waste so much. It also gets rid of the panic stations feeling after 5 mins when the stuff starts to go like jelly. This is what I will be using , and my hull will be of a decent size.

​The thickness of the mat is expressed as gsm….grams per sq metre. For a smaller vessel then some fine-ish stuff should be ok, several layers.

​I imagine it will leave a textured surface once covered in resin, but there again chopped strand will not be smooth either, and require a scraping of filler.

Ashley

Yes, my supplier is in Tullamarine, Victoria, Australia – not really handy unless you're planning a flying visit!

Although I used epoxy resin on the picket boat, my usual preference is general purpose polyester resin which is cheaper and quicker. The glass I use is cloth (not chopped strand mat), a satin weave of 85gsm which doesn't fray and drapes nicely. For the outside two layers of this should be fine. Sometimes I use a heavier first layer of about 185gsm followed by a second of the 85gsm if I want more protection e.g. for a tug. A final fill coat of resin optionally mixed with filler (e.g. micro balloons) fills any remaining weave and provides the thickness needed for sanding smooth without going through to the cloth. Speak to your suppliers, they should understand what is needed.

Something I forgot to mention about brushless motors – you don't have to solder up those fiddly suppression capacitors because they're not needed. That makes the installation less complicated in my book.

Yabbie1 (JP)

Hi Peter, the cloth and resin i use are from a company in Stoke on Trent, called Easycomposites, they have a web site of the same name, also a lot of how to do videos, they sec the resins and hardeners for the layup time etc, if you are close ish, they have a trade counter and are great for a chat to explain what you want to do

Regards

Mark

Paul

"Comprehensive"? Certainly – a huge exercise in data collection and presentation.

"Interesting"??? Didn't you hear the "thud" as my head slumped forward and hit the keyboard? Only for people who also bottle railway smoke, collect seaside pebbles or attempt to discuss the length of your intestines with total strangers. **LINK**

DM