An Easy Fix for Broken DC Motors Under 10Minutes

by ROBO HUB in Circuits > Electronics

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An Easy Fix for Broken DC Motors Under 10Minutes

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Hey there, You might have seen these DC motors pretty much everywhere, Whether it could be your small RC car you used to love in your childhood or a trimmer these are inside them that make those electronics work.

DC motor comes in different shapes and sizes, These are normally found inside the BO motor or in other words the geared DC motors.

The sad part about this DC motor is that if you provide more than 5v continuously or if the shaft is struck for some reason the motor doesn't work.

So nothing to worry about! In this instructable, I will show you how you can fix these motors in your house and give them a second chance.

Just a little background story!

I found this DC motor on my BO motor and when I got to know it was not working anymore I thought of discarding it and getting a new one, But wait I knew how these work, and I might find a solution here

With this in mind, I started to disassemble and the working principle found inside is very simple.

In the below steps I will be explaining almost everything about the DC motors, This is not just a fixing tutorial but also a how the DC motors work guide, With these things being said let us find a broken DC motor first.

Supplies

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The list of supplies needed here is pretty much less!

Broken DC motor( i got from BO motor)

Screwdriver of Philip and flat type

Wires for connection

Small battery source to test the motor

Compass or any other alternative

Now you might think the shape of your motor is different than mine, Thats ok this method works for motors from trimmer, Old RC car and other toys too.

The internal mechanism of all these are same only the small variation on sizes are seen, Note that these small dc motor can be also found inside trimmers too

Scavenge for Motor

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The first step here is having the access to your broken DC motor let's say the motor inside your RC car is not working or it could be the motor inside your favourite trimmer stopped working and such other gadgets where these motors play a prime role.

In my case it is a BO motor that we use to run many robotic related projects, I got to know that my car was not working due to a broken motor so i will be fixing the motor now.

The motor are connected using gears and in the end we have a high torque and low rpm gear motor.

Start by removing the screws using the star screw driver, save these for later, now remove the case and in the end, we have our dc motor.

Now since we have the part ready that needs fixing its better to clean it to be free from oil or other dust particles.



Finding the Broken Part

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The dc motor has a casing that could be easily removed if you know where exactly are its joints, The common type of motor has the fixings at the bottom, and removing that is a very easy job.

Use a flat head screw to loose the side grips that are made of aluminum to have access inside the motor, Gently pull the motor case and have a look at the issue.

The most common issue is burnt brushes and this reason happens because of seized shaft movement or overpowering supply to the motor.

If it has oil or other unwanted particles clean it and then we could move on to the next step.

Sub Breaking the Part

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The brushes are usually tacked using a small holder that is fixed to the base, It is easy to unmount from the base.

Just use the flathead screwdriver and gently raise this holder and now you can have the brush holder.

Remove the old brush and I would recommend replacing this totally with a new one because reusing this will add friction to the shaft and thereby increase the friction that will lead to inefficiency.

In the other way round you can also recycle this from another dc motor whose coils are worn out.

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Adding New Brush

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For the brush i will use copper wire that is found inside the cables or small wires we use in electronics.

Note that the big cables do not work here its because the wire that we use here should fit inside the brush holder slot, Start by peeling of the outer layer and have access to the copper.

Twist the copper so that the very firm braid is formed and it wont wear out during the working of motor, Trim the excess length and maintain a length of 1.5cm max.

Insert the wires one by one to the slot and press the strands of wire until the brush is strong enough, I recommend not to leave any excess wire outside the frame since this might interfere with the aluminum body and make the motor not to work.

After this is complete we are almost in the end stage in the motor recovery, but before let me tell you the logic behind this step.

Final Assembly

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As you can see the brushes are now upgraded and ready to be used, Insert the shaft inside this and clip the pins of the body.

Give this motor shaft a twist and provide power supply to the terminals and now the motor should work.

Now you may wonder how this motor got fixed? Yes you are reading the correct question!

Here the shaft end part also called as bottom part has 3 slots that are connected to the copper coils, When these slots are provided with power the coils create a magnetic field and these fields interfere with the permanent magnets.

The change in the emf or called as electro motive force cause the shaft to move that is responsible for working of the motor.

Earlier the carbon brushes that were broken could not provide power to the coils so the motor was not working and later we fixed it.

Video Tutorial

How to fix broken dc motor in very easy way

Here is the video of this project that shows the tutorial in the stepwise order but in the form of the video.

If you still have any questions let me know in the comments I will be happy to help you, Thanks, and have a great day.