I have two cordless drills. One that was dumped at work and another one that I bought at a flea market. Both had their motors burnt and smell like so. So I tried something radical: replace the dc motor. But were to find one alike?

Step 1: Secrets of the Elders!

I will reveal my secrets of material sourcing. There is a guy that lives in the city's dump (very common in Mexico) and has an army of people looking thru junk to find stuff tha might be worth money. So on sundays, he deploys his load of junk on the road, so costumers go through all of it to find useful stuff. I like the old saying "one man's junk is another's treasure".

Step 2: This Is the Key!

Find yourself one of those a handy-dandy tire inflators (new ones sell for 8 USD at autozone). But I found two junky ones for 3 USD.

Step 3: The Quintessential Part!

This is what you need, the motors of this small air compressors and the 12 V dc cordless drills are exactly the same. Remove it from the cylinder unit.

Step 4: Take the Pinion Out.

The pinion on the motor needs to be removed as it is not the same size of the one on your cordless drill. Use your prefered techinque. I use electric pliers clamped in a bench top clamp as a suport for the pinion, then use a screw the same size of the shaft to pop the pinion out. Suit yourself!

Step 5: Dissasemeble

Remove the motor from the gear reducer and desolder the wires. Repeat the previous step to remove the pinion.

Step 6: Put the Right Pinion

The pinions are different sizes, so be careful on the one that belongs to which one. This picture shows it better. Just put the right pinion in the new motor. Do it GENTLY, be careful not to damage the motor.

Step 7: Rassemble the Motor to the Gear Reducer.

Reattach the motor to the gear reducer.

Step 8: Solder and Reassemble.

Solder the wires. And put everything back in place. Watch for wires not to be trapped.

Step 9: Voila!

This two babies were resurrected ann you can notice that I attached lead acid batteries to them. While they might be hevier (one gets used to that, plus is like working out at the gym!), they are powerful.

So there you have it, junk stuff put to good use once more!