How to Restore an Old Dremel Tool and Replace Brushes

In this instructable I will be showing you how to revive an old rusty dremel tool. The shank nut is rusted and froze on to the shaft, the armature winding and field winding are also rusted. The shaft lock is also rusted so the shaft won't turn at all. Let's fix it!

Two Pairs Of Pliers
Flat Screwdriver
T11 Star Driver
Electrical Cleaner
Bench Grinder
Rag
New Brushes (Optional)

Using your flathead screwdriver remove the two blue plugs holding the brushes in. Be careful when removing the plug or the brush spring will fling the plug across the room.

Start by removing the four T11 start head screws. Now that the screws are removed, using your flathead screwdriver pry open the shaft end of the housing.
Once Pried open pull the motor out of the housing. First remove the rubber bushing from the bearing then unplug the black plastic piece that the cord wires are leading to from the field winding. Now pull the armature winding out of the field winding.

Using your bench grinder with a wire brush wheel start by gently polishing the rust off of the armature winding and shaft. Use light pressure you only want to remove the rust.
Now do the same with the outside of the field winding. Once shiny use sandpaper to shine up the inside of the field winding. Once shiny spray all of the parts with electrical cleaner including the housing.

To free up the rusty shank nut grab the shaft with a pair of pliers and grab the shank with a second pair of pliers and turn counterclockwise. Now that the shank nut is removed clean up the threads on the shaft with the wire brush on your bench grinder. Put a couple drops of oil on the threaded shaft and inside of the shank nut then thread the nut on to the shaft.

To free up the shaft lock start by removing the C shaped spring then knock the lock pin out from the top of the housing using a punch. Once out grab it with a pair of pliers and shine it up using the wire brush on your bench grinder, put a drop of oil on it then put it back in the housing then put the C shaped spring over the lock pin it should move up and down smoothly and easily.

Start by sliding the armature winding back into the field winding make sure that the four plug ins on the field winding are on the opposite side of the shaft then put the rubber bushing back on the bearing. Now plug the black piece back into the field winding and put the reassembled motor back into the the bottom of the housing. Now make sure the square piece of the cord is in place and place the top part of the housing over the motor making sure the C shaped spring stays in place. Once both pieces of the housing are pressed tightly together go ahead a put the four screws back in and tighten down snug.

To reinstall the brushes just set them back into the holes and tighten the blue plug down on them. I'm reusing the brushes but if you just want to replace them follow this step and step 1.

Spray some electrical cleaner on a rag and wipe the housing clean. Once clean put a few drops of oil on a rag and wipe down the housing this will put a shine on the dremel tool.

This dremel tool has officially been brought back to life. It's clean, shiny and it runs great! I hope this instructable will be helpful. Thanks for reading!