John,

Those are very interesting results, and nicely presented! One question, though: did you re-ballast the boat for the brushless run, so that it would weigh the same and sit equally deep in the water for both the brushed and the brushless laps?

Mattias

Even long time stallholders are like the rest of us – they only see what the rest of the trade generally offers. The model trade has seen brushless motors as the greatest thing to shoot fast models along, and has concentrated every last bit of hype at telling the world that brushless motors make fast boats go even faster. And faster yet. That is where they see the money to be made.

They don't see funding early retirement coming from the scale model close control market, so almost nothing is published telling of any of the advantages of a brushless setup in that field. Most manufacturers see that there is a big market in high power to weight ratio power plants. Try finding an advert for brushless motors/controllers that doesn't concentrate on high performance to the exclusion of all else. And remember that the motor in the link had to be fitted with a different shaft.

Just love the graph caption.

A few articles on the use of brushless motors and there controllers and knowhow of how to guess what might be good n any given situation would be useful. Having said that, we are not far removed from the days when motors were sold with the description "suitable for boats x inches long". Amazingly, they usually were.

Just a reminder of John Parker's feature article on brushless motors on this website:

**LINK**

Colin

Edited By Colin Bishop, Website Editor on 30/10/2016 17:56:09

Just as an aside, I was fitting out a new model yesterday with a Turnigy 2830/11 1000kv brushless motor, a FUSION Hawk 30A speed controller, 2S LiPo pack and my customary Hitec radio. I have no "soft-start" programmed into the transmitter, yet I found that the motor can be made to turn very slowly indeed – right from startup. I didn't measure it but I suspect that at that speed the prop would barely move the model – if at all. The use of the programming card makes setting up these ESC/motor combinations very easy and you can obtain quite wide variations in performance.

I would still be inclined towards using brushed motors for displacement models but I wouldn't now dismiss brushless motors as intrinsically useless for such applications. As with most things, it's a question of matching all of the pieces of the system together to obtain the required result.

As for the model trade, I've been there, done it, got the tee-shirt etc. There is no reasonable living to be made from selling 'proper' R/C models. Chinese RTF plastic models with garish colour schemes and double-figure retail margins are where most of the turnover is, so don't expect specialist model boat knowledge or treatment from yer average local "model" shop. Unless you're very fortunate in where you shop you'll be disappointed.

Dave M

If the prop is turning THAT slow, there won't be enough wash over the rudder to effect a turn of any reasonable degree, for it to be of any use in a steering competition.

A reminder of Editor Paul Freshney's posts on his Lubeck model fitted with brushless motors:

**LINK**

He says that speed control is excellent right down to very low speeds and attributes the smooth running to the high quality speed controllers. Like DM he considers fitting cheapie controllers to be false economy.

Colin

Ashley

Not missile technology, dear boy. Just watching some folk operate their models will tell you that proportional control is wasted on them – they use the sticks like switches i.e. it's either all the way over or centred. The result will be a model which flits around the pond at an unrealistically high speed and turns like a bluebottle in flight!

I don't use reverse much but it's handy to stop the model quickly when something appears suddenly in front of it. A blast of reverse will also usually clear a weed-fouled prop and get your model out of a bed of reeds if you're unfortunate to venture there.

Like PF I use Fusion brushless speed controllers and find them very good indeed, especially with the programming card. I have also successfully used the V3 30A marine ESC from Component Shop and would recommend either type.

Dave M

The radio and servos don't take much current, but in a boat that is only running at low power anyway, that can be quite a percentage of the total. If not accounted for, it can skew the figures. Using a UBEC to supply the radio would have included the radio use in the overall power use figure. Probably the same overall answer, but with slightly different figures.