Hi
Very helpful article and discussion thread. However, I would still appreciate expert advice on a motor/speed controller/prop combination for my twin proped Amati Riva Acquarama model, still in it's early stages of contruction.
I used a Turnigy D3536-6 1250kv brushless outrunner with a 100amp HobbyKing reversible car speed controller on my 34" Vosper fire tender (maybe a bit of overkill with the ESC but I had started with a 45 amp unit and this was prone to cutting out – overheat protection?). With a 40mm twin bladed Graupner prop, this boat goes well.
I am temped to go for a similar set up for the Riva which is about the same length but maybe quite a bit heavier. It would look much like the kit in Bob's Slo-mo-2. I want the boat to plane well but not to leap out of the water. I have some concern over cooling as the engine room space will be more confined than in the Vosper – maybe a bit more like Slo-mo-2. The is no opportunity to introduce air ducts into the enclosed space.
I am aware that outrunners have a lower kv, eliminating the need for a gearbox. On the other hand, water cooling would be more difficult and the car ESC can not be water cooled.
I think I will have to use Lipo batteries as there would be no room for the 12v 10 cell 5000mah brick which I have in the Vosper. Finally, I would opt for M4 drive shafts.
Any thoughts or advice would be much appreciated.
Jeremy