Propulsion System - Motors, Gears, etc


I think i will turn it down on a lathe.
Will be easier then build some coupler which also will increase the total length.


Perhaps you should adjust trust angle of the motor in order to avoid excess lift. We use to do so with air plane to compensate thé blade torque and upward lift.


@NoWind I’m getting a very similar Chinese brand gearbox which looks similar to yours. Have a SSS 360kV motor which also has 10mm output shaft. My concern is how to couple the gearbox to motor to ensure shaft and gearbox centre are absolute centric.
Does the gearbox flange you have fit the SSS? Where did you get this from?


stumbled on this tonight, might be useful,. still waiting for more parts…got a lower unit from a johnson 5hp outboard yesterday, with a 9.5 inch x 6inch pitch propeller, might give it a test,


Hey @g.gregory8
Interresting with this transfer gear, never see this before!
Reisenauer itself talking about lasermelting the gear to the shaft for high output…
I have made such great expierences with Loctide 603 that i will try to glue it first… maybe it will not work that good as in my eboards because the shaft diameter is smaller … but i will check first

Yes @reisenauer got a fitting coupler for the SSS… You can only use 3 of 6 Mounting Holes of the SSS
It got a “fine tread” which will fit to the Gearbox :

Its the red part sitting on the SSS



Can you please provide the link of this Chinese gearbox? Thanks!


@Antonbit Here’s the link. Although being an unknown quality I wouldn’t recommend at this stage. I was miss informed at the start regarding input type and shaft sizes, although they have been helpful. Hopefully it works out, I haven’t received yet.


yep, it looks like an optimal way, I was a bit afraid of it, but @moggieuk pictures helped a lot, turning it down then, thanks


Hi David,
have you heard back from Alien Power about the 50-100 KV brushless inrunner yet?


I emailed Bruno a few days ago about it… this is what he said

Hi. Yes. The motors is been modified because were lack of power. Now it will be 9 poles instead of 6 and y winding configuration with 0.38mm copper. I guess we will have them in 2 weeks


No idea what it means. Sounds amazing though. 2 weeks? Better get my board cut!



Got specs directly from tpp power on a 58mm 100KV motor. (think alien power supply gets his motors from there?)

Can’t tell if it’s a good motor or not (we are not convinced yet), but there might be someone here that knows more about this stuff than us. Please let us hear your thoughts. Would be nice to go with no gearbox.


I can’t tell if thats an inrunner? looks almost like an outrunner…


We received those same images from TP motor and a price that is getting higher and higher due to all the requests. Torque seems too low? Better to have the multiple of torque from a reducer and a higher RPM?


we figured out the less KV we go the less max Amp we can load on it… so if you go below 250KV it gets a problem for max power output… Solution would be to go on higher Volts again… With present motors we came to solution about 100mm Prop is about the maximum for direct drive and that`s the thing restricting max efficency…
So reduction gear still makes sence if you go for best efficency…wonder what planetary gear the Fliteboard guys using…should be reliable one…


The soft start module it’s very interesting… Which one have you installed?


There is no seperate module It’s is implemented into arduino code on the reciver that drives the esc.


With an Arduino, do you drive the ESC like a Servo in the code? Does it get PWM signals like for example 900ms to go half throttle? In that case you could program really nice curves into it.


Yep, we use the arduino servo library, on our ESC 90 degrees = zero throttle 174degrees = max throttle. And Yes, you can get whatever curve you like.


9 Pole motors are not possible. Pole numbers need to be even.