Bokonon
1 mW
Hi all, there doesn't seem to be much available on this forum (or others) about the Vinka mid-drives from Japan. A while back I picked up one of the new mid-drives from Wally World thinking it would be an interesting project. These come with a drive that is essentially a Vinka E20. From the factory these bikes come with a 36V battery, rated power of 250W, 80nm of torque, no throttle and a torque sensor.
Taking the drive unit apart (pics below), it appears to have an 88mm inrunner and approx. 60:1 reduction. The rotor shaft has an 8T helical gear carved directly into it. There is a small controller inside the case. No hall sensors.
Ultimately I want more power (a lot of hills here) no torque sensor, running 48V, and a throttle. My first attempt was to hook it up to a VESC. Ultimately I couldn't get the VESC to do much with it sensorless. There was a lot of stuttering, a lot of heat, and not much power even after a few weeks of adjustments.
So I am removing the motor and found this this 87mm, 85KV outrunner drone motor that fits inside the stator case on the non-drive side. This motor should have about twice as much torque as the factory motor. My plan is to add hall sensors and use it with a VESC, but I got stuck on a few things. Any advice appreciated.
1) The drive shaft would need to attach to motor's bell housing, then run through a bearing mounted in the drive case. I'm having a really hard time finding a shaft that will work. The rotor shaft from the factory motor is in the last picture. It is "stepped": 10mm for the gear part, 12mm for the bearing, then a "ribbed" 14mm part that fit into the rotor. I was thinking maybe to grind down the whole thing to 10mm, then use it with a 10mm propeller shaft adapter which are easy to find. Seems like a lot of work. When I search for this type of thing I mainly find "annular cutters"..
2) What's the best way to get the stator out of the metal "cup"? It seems to be pressed in there. I could just start cutting and prying, but there has got to be a better way...
Taking the drive unit apart (pics below), it appears to have an 88mm inrunner and approx. 60:1 reduction. The rotor shaft has an 8T helical gear carved directly into it. There is a small controller inside the case. No hall sensors.
Ultimately I want more power (a lot of hills here) no torque sensor, running 48V, and a throttle. My first attempt was to hook it up to a VESC. Ultimately I couldn't get the VESC to do much with it sensorless. There was a lot of stuttering, a lot of heat, and not much power even after a few weeks of adjustments.
So I am removing the motor and found this this 87mm, 85KV outrunner drone motor that fits inside the stator case on the non-drive side. This motor should have about twice as much torque as the factory motor. My plan is to add hall sensors and use it with a VESC, but I got stuck on a few things. Any advice appreciated.
1) The drive shaft would need to attach to motor's bell housing, then run through a bearing mounted in the drive case. I'm having a really hard time finding a shaft that will work. The rotor shaft from the factory motor is in the last picture. It is "stepped": 10mm for the gear part, 12mm for the bearing, then a "ribbed" 14mm part that fit into the rotor. I was thinking maybe to grind down the whole thing to 10mm, then use it with a 10mm propeller shaft adapter which are easy to find. Seems like a lot of work. When I search for this type of thing I mainly find "annular cutters"..
2) What's the best way to get the stator out of the metal "cup"? It seems to be pressed in there. I could just start cutting and prying, but there has got to be a better way...