A friend dropped by tonight with an interesting motor.
It is from a powerchair, and the wheel bolts directly to it. Normally it would run at less than 200RPM, on 24V SLA, for a few MPH on a small-diameter wheel, but the manufacturers have apparently tested it up to 65MPH on the same size wheel, something over a thousand RPM, which would take a couple hundred volts or so. I don't know if that was bench testing or on-road.
Being a powerchair motor, it is intended to run for long periods at max output, climbing hills/ramps, etc. Basically the batteries would give out long before the motor would be in danger.
So it should work for ebike use, too, like I used to do with the powerchair brushed motor/gearbox unit on CrazyBike2's original on-road drivetrain, running it's output thru the gears along with the pedals.
The catch? It's almost 30lbs! About 7lbs can be removed with the parking-brake assembly, which I would not need on a bike. The rear cover, that basically just protects that brake assembly, could be left off. A bit more might be machined off around the former wheel-hub, on it's outside and it's face, but that's all aluminum so it wouldn't be much weight. Most of the remaining weight is in the copper and laminations of the stator, and the magnets and flux ring of the rotor (inside the hub). Cant' ake anyo of that out.
So it will still weigh about what a hefty hubmotor and wheel would weigh, and I don't know what kind of performance to expect. I still would like to try it out, though. Would be interesting to see how it performs with a good gearing-up to at least 20MPH (just running it on the higher voltage packs I have nearly should do that), then run thru the NuVinci.
There is a challenge, however: It does not have a direct hall sensor connection. Instead, it apparently has an electronics board that outputs a sin and cosine function of the halls, based on this pinout sheet:
Neither of us is sure what the EEPROM data and clock lines are for--they may be to reprogram the hall board for specific uses of the motor, or perhaps they read out serially certain data from it, but we don't know what that data might be.
There's no way to physically access the halls directly, either, without removing the rotor (hub) from the stator. These are some VERY strong magnets, and it is going to take a fixture built for the purpose to pull them apart without risk of damaging either fingers or motor, so if a relatively simple (analog electronics) way can be found to use the SIN and COS signals to recreate three separate hall signals for a typical ebike controller, that would be great. I havent' thought of one yet, but I am not really good with coming up with stuff like that.
So anyone else that has an idea, I'd like to hear it.
It is from a powerchair, and the wheel bolts directly to it. Normally it would run at less than 200RPM, on 24V SLA, for a few MPH on a small-diameter wheel, but the manufacturers have apparently tested it up to 65MPH on the same size wheel, something over a thousand RPM, which would take a couple hundred volts or so. I don't know if that was bench testing or on-road.
Being a powerchair motor, it is intended to run for long periods at max output, climbing hills/ramps, etc. Basically the batteries would give out long before the motor would be in danger.
So it should work for ebike use, too, like I used to do with the powerchair brushed motor/gearbox unit on CrazyBike2's original on-road drivetrain, running it's output thru the gears along with the pedals.
The catch? It's almost 30lbs! About 7lbs can be removed with the parking-brake assembly, which I would not need on a bike. The rear cover, that basically just protects that brake assembly, could be left off. A bit more might be machined off around the former wheel-hub, on it's outside and it's face, but that's all aluminum so it wouldn't be much weight. Most of the remaining weight is in the copper and laminations of the stator, and the magnets and flux ring of the rotor (inside the hub). Cant' ake anyo of that out.
So it will still weigh about what a hefty hubmotor and wheel would weigh, and I don't know what kind of performance to expect. I still would like to try it out, though. Would be interesting to see how it performs with a good gearing-up to at least 20MPH (just running it on the higher voltage packs I have nearly should do that), then run thru the NuVinci.
There is a challenge, however: It does not have a direct hall sensor connection. Instead, it apparently has an electronics board that outputs a sin and cosine function of the halls, based on this pinout sheet:
Neither of us is sure what the EEPROM data and clock lines are for--they may be to reprogram the hall board for specific uses of the motor, or perhaps they read out serially certain data from it, but we don't know what that data might be.
There's no way to physically access the halls directly, either, without removing the rotor (hub) from the stator. These are some VERY strong magnets, and it is going to take a fixture built for the purpose to pull them apart without risk of damaging either fingers or motor, so if a relatively simple (analog electronics) way can be found to use the SIN and COS signals to recreate three separate hall signals for a typical ebike controller, that would be great. I havent' thought of one yet, but I am not really good with coming up with stuff like that.
So anyone else that has an idea, I'd like to hear it.