From Neil Winfield:

"Ok here's one for any of you. I have just orded a speed controller from Action and noticed on their diagram the wiring set up showing + and – wires. Now the thing is how on earth do you tell the differance on the motor when both terminals look the same? Oh it's a graupner motor."

The wiring diagram will NOT show the polarity of the connections between the ESC and the motor, simply because it changes as the motor goes from one direction to the other. We use Blue and Yellow for these two wires on our published coloured diagrams. See here for an example **LINK**
The simple rule for connecting the ESC to the motor is that, once done, if the motor runs in the opposite way to that which you require then just swap over the two connections to the motor brush terminals (or ESC output screw terminals, when fitted). The wires from the battery or distribution board to the ESC, however, ARE shown as Red and Black and ARE polarity-sensitive. Get these two the wrong way round and you'll be seeing the Magic Grey Smoke…………
Dave M

Edited By Colin Bishop, Website Editor on 05/10/2012 15:12:40

Edited By Colin Bishop, Website Editor on 05/10/2012 15:18:13

I have heard that this variety of speed controller DOES NOT have any grey smoke in it.

Ashley

Blast, do you know, I thought it was the grey smoke that made them work!! and if the grey smoke leaks and comes out…they stop working..

I shall have to think on this.

Ashley

Difficult to reply objectively when one is in commercial competition with these units. I can only speak of the feedback I've had from dozens of customers about them and from what I have read on the various Internet forums (fora?).

Comments are mainly thus:

They are vastly over-rated in terms of their continuous current capacity;
the quality of the components and manufacture is poor;
they frequently don't work at all, straight out of the packet, or they last for only a few seconds;
there is no chance of repair or refund if purchased from an overseas supplier (egf Hong Kong via E-Bay) and little chance even if you buy one with a UK distributors "badge" on it.
Their only real attraction is the price, but as we all know, the cheapest is rarely the best.

My answer to you directly, Paul – in the light of all I know and have read about them – is that I wouldn't touch that shiny "50A" one with a bargepole if I were you. It'll be lucky to carry more than about 15A before blowing up or just stopping working. If you want a single ESC for both motors then use either our P98 or an Electronize 30A job. Both are guaranteed, British-made from good quality components, and repairable if you do something daft.

Caveat emptor with alarm bells on it, dude.

Dave M

Edited By Dave Milbourn on 07/10/2012 15:22:03

Chaps. My very limited experience with higher current applications and ESC`s is….

Beyond a certain amperage, forced cooling becomes neccessary. A 25A ESC (for instance) will not actually run at 25A without getting warm, then hot, then hotter…and.

I believe certain makes of speed controller have heat sinks and can run reliably at higher amperages…but a certain make of encapsulated ones does not have this luxury…sorry..important feature and so would need doubling up for a twin or whatever motor application. However even the other make of ESC I think would probably need some sort of air throughput in the boat to keep at a reasonable temperature (?), or the inside will just be like an oven.

My current project has a motor on it drawing amps the like of which I am scared to measure for fear of bending the needle on my ammeter, and the 60A (yes!!) ESC is watercooled but appears to be coping well. I am currently running this combo on 8.4v, but the ESC will handle a 3 cell Lipo (so roughly 12v) At which point I recon I will have to save up to buy some thicker wires than I have at the moment if not solid rod. I was going to install lighting but the glow from the battery wires will probably be sufficient. Scary stuff, but not so unusual in the model aircraft world. When i see steam coming out of the water cooling outlet, I will begin to worry.

But…if I direct ir rearwards I might get some more thrust !!

A few new men on the pond are Lipo and brushless fiends and are using all sort of stuff I have never heard of. There do appear to be some good cheaper makes out there, but you have to know which ones !!! (not for marine use specifically I hasten to add).

Ashley. did they ever make a 30A Bobs board??