Originally posted by DJ2759
.....I know I need to remove the motor and remove the back or front cover....but then what? Should I use a special solution or just dry clean? Anything I should guard against?
Dale: Unless it is an absolute emergency, you would be wise to call PSI and get their input before messing with the lathe.
That being said, if you chose to proceed without checking with them, the following may help. First off, on most DC motors that I have seen, it is not necessary to disassemble the motor to access the brushes. And you may not even need to remove the motor from the lathe. Before working on the motor, be sure to pull the plug from the wall. It is not enough to just turn off the power switch.
Look on the outside of the motor case for two little plastic protrusions about a half inch in diameter. They will be on the end of the case farthest from the pulley end and the will be placed 180° from each other on the case. Each will have a slot or a cross to accept a screwdriver that allows you to remove a little circular cover. Be very careful here as those covers are made out of a plastic-like material and are very brittle. They are easy to chip/break if you are not careful. The brushes are under these covers and are spring loaded. The covers are liable to go flying when unscrewed so I usually loosen the cover with a screwdriver and then finish the removal with my fingers to control the cover.
With the cover off pull out the brushes. Pay attention to any orientation indicators. Most don't have any; but occasionally you run into an oddball. And be gentle handling the brushes....they are not terribly fragile; but you could easily break one if you drop it on a hard surface.
Take a look at the end of the brush opposite to where the spring is attached. It should have a slightly concave shape due to rubbing against the rounded contour of the motor shaft. It is only this concave surface on the end of the brush that needs cleaning and no liquid cleaners or anything of the like is necessary. What you need to do is "LIGHTLY" scuff up the concave surface of the brush. Be very gentle....you are not trying to sand off material or flatten the end of the brush. I would use a little piece of 600 grit sandpaper or a comparable grit in MM.....1800.
When completed, put the brush back in the motor, observing any orientation marks if present and screw the cover back on. Because of the spring, it will be a little tricky to get the cover back on correctly. Be careful not to get the cover cross-threaded.
You "MUST" be sure to get the brush oriented properly!! Think about how the round surface of the motor shaft will be oriented inside the motor and then orient the brush so its concave surface will match with the surface of the motor shaft.
Hope this will be of help. Do be aware there other things that could cause your problem so this may not fix your problem; but it is the first and easiest thing to try. And, of course, all of the above may not be applicable at all if the PSI motor is of a different design that what I am normally used to seeing.
As to the comment about running VS tools on a GFI circuit, I would say that anything is possible; "BUT" I have never seen that information ever offered before and would like to hear it from a licensed electrician or EE before I am convinced. If someone is having a problem with a VS tool on a GFI circuit, my feeling is that it is more likely that the GFI is faulty or wired incorrectly.
