by waaytoomuchintothis » Sat Jan 13, 2018 12:32 pm
It seems everybody has a favorite method for this. It is valuable as a commutator cleaner and as a minimum wear break-in tool. The following is an edited version of instruction I got a long time ago and kept in my computer.
In a glass of cold water, submerge that dude and run it for about 60 seconds at 3-5 volts. I don't get fancy here, my controller is hooked up on this test rig and I just run it at low speed. If you run it longer, you begin to "use" the brushes without benefit and possibly damage the commutator. This run grinds the brushes in to seat perfectly with the comm and shines it up as well. When the water settles after 10 minutes or so, you'll see tiny gold flakes on the bottom of the glass. Now if I had run this motor up to top end without doing this first, the extreme heat would groove/scar the comm and top performance is lost for good. At this point, no...do not run that motor up. Not yet.
The water needs removed and so do the remaining flakes and brush dust particles. Alcohol dunking does the trick. Get the whole motor submerged, especially the comm; and then run it for 30 seconds or less at the very low end. Out of the glass and then pat it dry. Spin by hand and help the inside to dry out. 15 minutes or so and the rest of the alcohol will evaporate. If you are in a hurry, compresed air will dry it in a few seconds. The answer is still no! Resist running it up.
The next thing to do is to oil the bushing. You can be sloppy back near on the output end. Be very careful on the comm end bushing - just a dot. This needs done as a regular race prep too.