Tow boogie project, help needed

Build, Repair & Mod
#1

Hi everyone
I’m a foil beginner, and I do want to expand my foiling time by building a tow boogie.

my idea is to make a twin-engine boogie, with two N5065 - 270KV - 1 820W motors that I have from an aborted e.skate project.
(270KV N5065 5065 Brushless Motor For DIY Electric Skateboard Scooter Multicopter Sale - Banggood USA)

The dual motors might make it steerable with a 2 channel radio, to make it come back to me, by using the left or right motor.
If possible a simple system like this one ( Electric Tow Boogie - #20 by jakebarnhill1) , one on the right and one on the left of the board. (maybe resizing it with Tinkercad ?)

Everything powered with a 2-6S 80A UBEC Brushless ESC, and 2 4S or 6S lipo, not sure.

I’ve been reading around the forum, but I don’t know how to attach a prop to the short staff of the motor, and where to find two counterrotating props suitable for this.

any hindsight appreciated, thanks guys
keep safe
Alex

#2

You probably need to print the props yourself, esun pla+ worked for me. Cut the shaft after the circlip and fix the props on the opposite side, directly to the bell. Not sure if two 5065 deliver enough power to get you on a foil. You also need 2 ESCs or a dual ESC. Maybe use just one 63xx outrunner and a servo controlled rudder to remote control the direction.

#3

thanks. I now realise that the props need to be on the opposite side of the motor, clever. no need for a shaft adaptator.
yes, a bigger and specialized motor would be the easiest, bust costly solution. I want to try with what i have lying around though.
do you think a prop could be just shrinked by a certain % to adapt it to those motors ?
i might try that.

#4

I believe that it is not possible to produce a quality propeller for the N5065 - 270KV motor on a conventional home 3D printer (FFF/FDM)! Plus, you can’t find a 3D file of a suitable propeller anywhere and this motor is not suitable for the project.

#5

I beleive it is, nevertheless, I think 2 motor is much better than 1, as the small boat/board struggles with torque. If you run 2 motors, run them opposite direction and this problem is gone.

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#6

There are loads of RC boat props that would work with those motors. Something in the 70mm range would probably be a good place to start.

#7

I do not think 2x 70mm props will be enough to get you on foil:
You will have cavitation before they can develop sufficient pull.
Depending on your weight I would assume you need a prop area equivalent to that of a 140mm diameter propeller at minimum which would be ~2x 100mm diameter.
Not sure if those motors will have enough torque to do the job.

Most working efoils I know even use a 150mm and bigger diameter prop which could be replace by 2x 106mm props…
Personally I use a 165mm diameter prop on my foil which would be equal to 2x 117mm…

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#8

It’s a starting to so that you don’t cook the motors… Once you’ve run it like that you can then look at whether the motors can handle bigger props.
At higher RPM’s there are cases of guys that have got enough speed to foil with single props in the 100mm diameter range. Obviously the smaller you go the less efficient it is and your technique needs to be much better for starting…

#9

wow guys, thank you !
you steered my project in a cool different direction.
i think i will try a dual motor RC boat setup on a boogie board. Motors on top of the board with shafts to increasingly bigger props. reducing drag by reducing things in the water.
it’s going to be quite inexpensive, I hope, and if it proves unsufficient, i will buy a bigger, more standard Efoil motor.
thanks again i will let you know how it turns out

#10

Curious how this concept went. Steering via 2 engines would be really cool! How’d it go??