Looking for information on rewinding armatures for 3 pole motors or replacement minitrix motors
Rewinding is fairly straight forward. First off you want to get replacement wire of the same size. Wire is sold by “American Wire Gauge” (AWG) sizes. You want to measure the diameter of the existing wire with a pair of vernier calipers. That means just the copper diameter, not the copper plus insulating varnish diameter. Which means you have to strip the varnish off. You can do this with ordinary hardware store paint remover without nicking the wire. Then you look in a copper wire table to convert from thousandths of an inch to AWG gauge. Copper wire tables are on line and in the CRC Handbook of Physics and Chemistry.
Then count the turns in the winding as you take them off. If your replacement wire is the same size as the old wire, then you will be able to fit the same number of turns of new wire onto the armature. Try to get the same number of turns onto each pole. It is also important to get all three windings wound the same way (clockwise or counterclockwise) , so they all pull in the same direction. And wire them in the same way. If you wire a coil in reverse it will pull in reverse. Take good notes of the old armature. Number each pole and record the direction of wind and to which commutator lugs is it wired. Strip the ends of each winding and solder them to the commutator lugs.
For extra class you can balance the newly wound armature. Set a couple of single edge razor blades upright and lay the armature shaft on the blade edges. The heavy side is the down side. Make the heavy side lighter by filing or drilling material away.
Instea of going to the trouble to rewind the stock motor, you’re better off replacing it with a five-poler. It. Will give you much better slow speed performance.
The smallest armature I ever rewound was from an electric drill. That was back in the '60’s. I would replace the motor with a new one. But rewinding the old armature would be a very interesting project. Post your progress here.