A 385 motor intended for 15 volts running on about 6 or 7.2 or 7.4 volts controlled by an Mtronics Viper 15 is probably the answer. Prop shaft – M4, length to suit your layout. Coupler to suit motor shaft diameter at one end and prop shaft configuration at the other.

Whether you can actually install any of this depends on how the model was made, and whether it was ever intended as a working, floating model.

Eric. There is no actual right answer to outfitting your boat, as you are bound to get conflicting views on motor size and so on. It is not a science, more of an art, despite that some people do like to do calculations.

​We will wait for the pictures. That shaft sticking out looks to be a 2mm job, which we would all agree is too small.

​No one will deny a 4mm shaft would be the right size, it is the common diameter, and the red/black u/j type couplings are also widely used, although some prefer the rubber joined versions.

​Just going on the size of it, my preference would be an MFA 540/1 low power motor on 7.2v, but brushless are popular..something giving perhaps 8000 rpm on your chosen battery voltage.

​Ashley

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Eric. I had written a lengthy thesis on the outfitting of a boat, but will wait for the pictures.

​The ESC and receiver can go anywhere convenient for access, preferably not on the floor in case a drop of water gets in. Velcro sticky tabs are as good a way as any of securing the receiver. ESC could fit in a pocket somewhere…as it will be a low power one, it is not likely to get hot.

Picture of the installation in my MFA Seahawk. A sizeable hull, fibreglass so clear of frames and so on. ESC strapped to cross beam on left. receiver at bottom in plastic open box. Brushless motor, double  red plastic U/J coupling since replaced with an all steel version)

Ashley

Edited By ashley needham on 08/08/2017 20:05:27

Edited By ashley needham on 08/08/2017 20:08:17

In this case yes. Both the motor and ESC are water-cooled. The battery gets very warm when running this setup. I am afraid to put a wattmeter on it…..

However, nothing has melted yet.. The motor used to be in my big KM Ecranoplan, running 9.6V. In the Seahawk I am using 7.2 and a slightly smaller prop, so things are not quite so scary.

​Ashley