Remove a Wheelchair Motor Brake


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My name is Randy and I am a Community Manager in these here parts. In a previous life I had found...

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!

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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.

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    17 Discussions

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    randofoDonaldB80

    Answer 4 weeks ago

    No. This just makes it easier to control the motor with a microcontroller or use it in other applications where you might not need the brakes.

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    Thomas Searchfield

    7 weeks ago

    Great tutorial I would still like the wheelchair controller to work with it but now it's not working and showing a brake error . I think this is because it wants to put the brakes on but there's no resistance there so it thinks it can't move. Do you know what the resistance of that brake? is as I could trick it into working by just adding some resistors on . Thanks

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    randofoThomas Searchfield

    Reply 7 weeks ago

    I unfortunately don't. You could try measuring the brake coil with a multimeter if you still have it.

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    JcCo3na

    2 months ago on Introduction

    Thank you for your reply, I already remuve the magnect break from the motor. It's 24v and I check the coil with a multimeter and I see 63.5 onmios, when I conect the power 24v direct to the break It doesn't work. I check the ppwer with the miltimeter the conecetion and I can see 24v get right on the wire and the clam comin fron the battery. I will apreciate your advice.
    Thank you and good bess you.

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    randofoJcCo3na

    Reply 2 months ago

    A thought... are you giving the magnet enough current? Is it fully enegrizing?

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    JcCo3narandofo

    Reply 2 months ago

    Hi Randofo, yes I delivery 24v to the magnect and I don't see any accion. I cheack also the air gap 0.50mm so its correct as some indications on other videos. But i don't see it work. Could you tell me if any way to make this magnect work again?

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    kittendorfk

    Question 2 months ago on Introduction

    Jazzy 600 custom Beach buggy was caught in flood, I removed motors and they ran once
    electronic brake was removed. When reinstalled into power chair will they run without e-brakes?
    KK
    Port Charlotte, FL

    1 answer
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    randofokittendorfk

    Answer 2 months ago

    I don't know if they will run without an e-brake. It's probably not a good idea to install them without this feature. These instructions are meant for repurposing these motors for DIY projects.

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    JcCo3na

    Question 2 months ago on Introduction

    Thank you for all tha information that you bring, I been working on a electric wheelchair, that it have the same motor and electric break that you show in the pictures. I would like to know wath is the problem with the break I already unsable and I see with multimeter that it have 62.5 onmios but when I conet power (24v) I don't see the break works, i conect direct to the terminals. Cuold you help me ? Bring me ideas what can I do. Thank you for your time.

    1 answer
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    randofoJcCo3na

    Answer 2 months ago

    The brake is a very simple mechanism. When it is powered, the electromagnet fires up and releases the brake.

    If the electromagnet is not being powered, the brake won't work. I would check the wiring and try to power the magnet directly (if possible).

    Also, make sure it is actually 24V (and not 12V, 36V or 48V).

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    boncle

    9 months ago

    The links to Alltrax are not working, but google finds them

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    DavidA723

    1 year ago

    Thanks - that brake is rather confusing to the uninitiated.

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    eslipak

    2 years ago

    Thanks! Very informative (and handy). I wanted to know how to do this for a while now. Good Work!. Any other tip you have will be very welcome! Maybe any tip about wheelchair controler?

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    randofoeslipak

    Reply 2 years ago

    Stay tuned for a "Large Motors" Class in the next few days :)

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    The ElectrobotRobotsMaking

    Reply 2 years ago

    Shorting the terminals of the motor will result in a braking action, but not as good as a mechanical brake.

    If you are using a H bridge to drive the motors, you could short the two terminals of motor by driving both terminals positive or negative at the sema time.