Removing the electric safety brake from a wheelchair motor is a quick and easy thing to do. These instructions are meant for people who are hoping to reuse the wheelchair motor for DIY projects. Disabling the safety brake makes controlling an electric wheelchair motor with an Arduino (or other microcontroller) significantly easier by helping to prevent accidental current surges that can occur if the motor is powered while the brake is engaged. This technique also allows the motor to be powered at 12V DC, without having to worry about powering the brake at 24V DC.
You can learn more about this in my Large Motors Class.
Under no circumstances should this be done to a motor that is in use on an actual wheelchair or mobility scooter!
Step 1: Take Off the Wheel (optional)
Loosen the nut that is holding the wheel in place and remove it. This is not entirely necessary, but makes the process much easier.
Step 2: Open the Back Cover
Remove the screws holding the back cover in place, and then pull it off the back of the motor to reveal the brake assembly.
Step 3: Remove the Top Disc
All wheelchair motor brakes are going to be slightly different, but the general idea is the same. Basically, this process involve removing the components holding down the tension spring and an electromagnet.
To start this process, remove the top disc, and the large washer surrounding the brake mechanism's center nut that is holding down the tension spring
Step 4: Release the Spring
Use a wrench to hold the nut in place, and very carefully remove the bolt from the center. Keep in mind that as soon as the bolt is free, the spring is going to launch itself, and whatever is sitting atop it.
It is recommended, at the very least, that you point the mechanism away from you while you do this. Additionally, as the bolt is close to being unthreaded, remove the wrench, and hold the mechanism firmly with your hand by applying strong downward pressure. By doing this, you can slowly release the tension from the spring with your hand.
Once free, remove the spring and whatever is sitting atop it.
Step 5: Take the Electromagnet
Remove any bolts holding the electromagnet in place.
Pull the electromagnet (and its wires) free from around the shaft of the motor.
This is a very strong high-quality electromagnet. It may come in handy for future projects.
Step 6: Put the Back Cover Back On
Finally, once all of the parts of the brake have been remove, but the brake cover back on as not to leave the motor's back shaft exposed. If it is not covered, things could potentially get ensnared around the shaft while it spins.