OK...
Pakirk, I think that they are the motors, but no gearbox. I thought direct drive was the answer. Going slightly off topic, will a gearbox not slow things down? or am I totally off the mark. I was thinking, with say 3:1, everytime the motor shaft revolves one turn, the propshaft will only turn 1/3rd, whereas direct drive, one motor shaft revolution equals one propshaft revolution?Are you running 3 x 12v nimh's? to get the 36v?
Stav, yep its a heavy lump, but a 55mm prop? Am I running the totally wrong prop at 40mm 2 blade "s" type prop. It had a 3 blade cheap plastic 50mm on it when I got it, and it was very slow, Hence I went to a small 2 blade (dont really understand the prop thing) but I remember turning up at 2006 Fireboat funday at Branston water park with my Dad's Fireboat, which had a 3 blade brass 45mm prop, and it immediatly attracted a whole host of people saying I needed a much smaller 2 blade "x" or "s" prop to make it move at any sort of speed!
Bradboat, 15 to 20 mins would be utopia for me! I tried a 12v 3300nimh, but it was slower, and no increase in run time, I think because I can go up to 19.2v with the graupner motor at 12v I was underpowering it
Malc and Martin, I dont really understyand the figures provided on the Graupner motors. I tried to get some info from the graupner boys at the Ellesmere Show, but just got more confused! I just thought, the 12v will take more power, although the revs are lower. I tried a very high revving Graupner 600 bb turbo ballraced 9.6v motor, but it was working too hard and kept overheating, draining the battery quickly.
So lets assume you guys with the knowledge, have my boat, 48" Huntsman, all ply, and quite heavy. Ignore the esc. You are entering a competition, and have to obtain the longest "flat out" runtime, so you are against the clock, and have to cover the greatest distance. You have to choose from a Graupner 12v 700bb turbo, the Johnson dark horse, any battery combo, any prop. What will you use, there is no practise or set up allowed, its just experience and gut feeling!
Off you go!! (maybe this should have been on the main forum?)
(many thanks!)