Boat project $20 dollar hull

 

 

For your 7 Year old i would go a number bigger with the boat, because the small ones are not easy to handle.

I would recommend something like the NTN 400. If it gets too slow some day you can easily upgrade the Motor (and ESC).  And you get the Hardware either here or at r2hobbies.

 

Best Regards Max

 

I would recommend a size from 450 to 600 mm with a 28 mm diameter 4200kv Inrunner at a 2s Lipo (4-5000 mAh) and a prop from 33 to 39mm with a pitch of 1.4 x diameter. That gives you a speed in the range from 45-60 kph.

My boat of that size pulls around 60 Amps when accelerating and 40 Amps at full speed in a straight line. Speed is close to 60 kph according to GPS, which is more than enough for a beginner.

 

For the prop shaft you can use either a 3.2 mm flex shaft or a 4 direct shaft. normally for a stepped hull the Propeller should be at a distance from the rear of the boat that equals  8-10 percent of the hull length and with a little gap between the propeller core and an theoretical line from the step to the rear. (i have to find a picture...)

 

 

Maybe you check a forum for rc raceboats.

 

I would recommend:

 

www.rc-raceboats.de (its a german forum  but it has an international section)

 

 

 

Best Regards

 

Max