They are normally pretty manky when you get them and need so cleaning up.
My process is
- Strip them down to bits, taking photos at each step.
- De-grease the entire thing with petrol and a on old toothbrush. (Goggles, gloves, outdoor space and obviously no smoking people!)
- Make sure that each electrical carbon brush is isolated from the case, and replace each feed wire with 5A flexible cable. Add a third earthing wire to the case, as close as possible to the brushes.
- Fit 100nf capacitors between the brushes, and each brush to the earth point, so that's 3 capacitors. If you don't do this the moor can generate high frequency noise interference which will attract the attention of all around you, including the authorities,
- Grease all moving parts with SILICON grease, not mineral grease, that can damage the nylon parts apparently.
- Clamp the wires to the case with two cable ties and test with a 12V source.
Window MotorsI looked at using window winder motors, because they come in pairs and will be perfectly matched, but here the axle is fixed to the chassis and the rubber drive wheel moves round it, which isn't quite what we need.
However I came across a really interesting article on "The Bit Bang Theory" blog which solves this problem by stripping them down and re-assembling them with a fixed axle. I f I can make this work then that will solve another problem, especially for smaller projects.
Check out the article at http://thebitbangtheory.blogspot.pt/2013/05/high-torque-encoded-dc-motors-for.html
and let me know what you think