Single/Side Shaft Hub Motor Build/Modify

[Mihai_F]

Hello everyone and happy new year, with amazing builds and adventures!
So here it begins with an new thought, i'm interested in making or modifying two e-bike hub motors or hub outrunners from hoverboards or else, to have an single side thick and sturdy shaft, and have them installed with a 20" rims, on the front end on my trike for 3. The power level needed is about 350 to 500W (each) and has to be low speed and with good torque.
I have two 140mm OD outrunners, 27 teeth 30 poles, which i used to test my FOC algorithm, and they do have low speed and good torque. The problem with these motors is, that the rotor is made from plastic and has small bearings (6000 2RS).... so i would need to remake/ build the motor using the stator and the magnetic array from the rotor.
Before i embark in this project and start making the actual design, i ask you if any one has done this single side shaft conversion to a hub motor before, or if there is this kind of motor out there and does NOT cost 1000$, i found such motors out there and are insanely expensive.
The cost part is sensitive on this project
here si a sketch of what i'm thinking to make, and some photos of the motor parts that i have.

 

[gromike]

Not all that expensive, and a lot easier than your DIY:
48V 52V 1500W single side shaft hub motor

 

[Mihai_F]

That is cool motor, unfortunately here across the pond, in the land of "unoptanium"(europe), such good stuff is not available. Although they do export it, but upon import in my country i'l be ripped with taxes for two of those , and that is way out my budget.
So the alternative, i found two used hoverboard 6,5" motors on the net, at e bargain price (20 euro), they have 16mm single side shaft and about 350w. The plan is to remove the tires, and then see how can i add flanges or drill the spoke holse in the existing flanges, and then add an adapter flange for the disk brake, so it is all about flanges , i'l come back with photos soon.

 

[Mihai_F]

Back with the photos with the motors

 

[Mihai_F]

I had cut of the tires of the motors, the outer flange is thick and big enough to drill holes for the spokes, the inner one unfortunately is not thick enough, it has some empty spaces (lightening holes) in the thickness, and it does not seal the motor any more since there is no tire any more to cover the empty spaces. So i believe the inner flange i will make a new one and also maybe have the disk mount in it, made in a single piece. Also disassembled one motor so i can "reverse engineer" the winding, it is wound with 3 parallel strands of 0.5mm copper wire (Y terminated), KV is about 20.7rpm/volt, and that might be a bit of an issue when wheel diameter increases from 165mm to 540mm, for ex: at 830rpm (40V) 165mm the wheel speed is 25km/h, but at 540mm(20"rims) the wheel speed is 84km/h for same rpm. So a rewind with a KV of about 10rpm/volt might be more suitable for my low speed high torque application, but will see.
here are some photos of the motors so far.