Page 1 of 1

Preparing an e-motorcycle build

Posted: Thu Jan 21, 2021 6:37 pm
by Bikerider
I did some homework and I am anticipating building an e-motorcycle. I have a motorcycle frame to start. I want a single speed design so the encoder is needed for low speed control.
I looked at the Prius MG1 and it appears to be a 23-27KW three phase motor with an encoder feedback. Although the motor is used as a generator, I would assume that it would make a good motor as well. It has magnets in the rotor for low speed torque and efficiency. I have a machine shop with CNC capability. My vision is to build a housing for the rotor, encoder, and windings. I would flood it with light weight oil for cooling. For batteries, my plan is about 300-600 (18650) batteries. My CAD model will help me determine the exact number. The third part is the controller and is why I am here. Is there an EVBMW board that would drive the MG1 inverter in a closed loop( reading encoder) operation and will the Prius inverter for MG1 work in the mode to power the motor? Also can the MG1 inverter be isolated and what would be the estimated weight?

Re: Preparing an e-motorcycle build

Posted: Thu Jan 21, 2021 6:42 pm
by johu
Great project, talked to another guy these days who does something similar with a smart motor and Gen2 inverter. He actually cut down the inverter to bare essentials, I hope he will post here soon.

So, Prius "machines" are synchronous and use resolvers, not encoders. I'm saying machines because there is no difference between a generator and a motor.
You can use this board for running the Gen2 Prius inverter: https://openinverter.org/shop/index.php ... duct_id=63

Re: Preparing an e-motorcycle build

Posted: Thu Jan 21, 2021 8:52 pm
by Bikerider
Thank you very much for the prompt response. I see that the driver is designed for MG2 inverter. That would tempt me to go with the MG2. It would be crazy fast but would allow about only 5-10 minutes of ride time.

Re: Preparing an e-motorcycle build

Posted: Thu Jan 21, 2021 10:26 pm
by johu
It will work with MG1 as well, the included docs reference MG2 because it is the stronger one.

Re: Preparing an e-motorcycle build

Posted: Thu Jan 21, 2021 11:04 pm
by SciroccoEV
Found this online some time back;
https://nicjam.es/projects/derpbike/part_1/

Re: Preparing an e-motorcycle build

Posted: Thu Jan 21, 2021 11:24 pm
by Bikerider
That is great. I should get over an hour of ride time. Now, I need to go to the junk yard and get a controller and a transmission. I will then disassemble and make measurements for my CAD design and budget. My target is <250 lbs and a lower center of mass than the conventional motorcycle doner. I have seen on the web where 2GEN MG1s have a capacity of 23, 27, and 30 KW. Do you know which is correct?

Re: Preparing an e-motorcycle build

Posted: Fri Jan 22, 2021 12:03 am
by Bikerider
Thank you SciroccoEV, My housing thoughts are to make it with aluminum plates and seal them with orings. I would machine cooling fins wherever possible. It will be flooded with oil with possibly a radiator and vent. I would have two oil ports on the housing. each one at an angle near the edge of the stator to generate flow. If they are not needed, they will be plugged and renamed inspection ports. If more oil flow is needed, a pump will be used and I have not decided if the stator volume will be flooded or not. I will also need to determine how much clearance is needed between the sides of the stator and the housing ends to avoid eddy currents. BTW, I am on the US side of the pond.