Motor winding, 8 years later

These are the 1st motors specifically bought for direct driving wheels. All previous motors were bought for quad copters or brushless gimbals. The journey begins with stock Propdrive 42x48mm 650kv motors, $30 each if they're lucky enough to be in stock. Rip off the C ring & write the numbers on all the poles.

The hardest part is removing the stock winding. It was easier to remove from Hextronic DT750's. It just came off in a continuous string. The Propdrives are so heavily eurethaned, the only way to get the windings off is to cut down the middle without damaging the powder coat. Then rip off the windings from each side of the pole.


All the leftover eurethane must be scraped off the poles to free up enough room for the maximum turns, yet without damaging the powder coat. The lion kingdom uses the same winding diagram it used 8 years ago from an unknown internet forum.

To get the most torque, put on the most turns that will fit, but more turns also reduce the maximum RPM. The lion kingdom guessed 70 turns of 32AWG, but after finishing, the motor would clearly fit 80 with careful winding. This resulted in lots of torque & heat at 10V 500mA. This was the hottest lions would take it with PLA & it would be for starting only.

Lions don't really know the required torque or have a way to measure it. Going 6 miles with maximum torque applied to 2 motors would burn 200mAh/mile, such a ridiculously low number, lions suspect the torque is too low, the turns count is too high to achieve the required speed or past motors were way out of spec for the application. All previous vehicles took 300mAh/mile with transmissions. The entire traction system with 2 motors has to be built to really know.


The next step is the power supply. The current is low enough to use L6238's, but more margin would be provided by repurposing cheap ESC's as dumb H bridges. The problem is cheap ESC's don't have UARTs connected to the PWM pin. They would have to encode the H bridge control as PWM or some kind of bit banged RS232. L6238's would be the simpler solution.