View Full Version : 6mm square key to pull a ac/dc motor brush seat?

07-21-2014, 11:59 PM
I'm trying to disassemble a Precise rotary tool (what a Dremel wants to be when it grow up) that got something inside or has a bad bearing. It seems I need to unscrew the brush seats from the motor before I can pull it from the chassis. Never done this, it seems to need a 6mm square key, but it might be tapered like some plumbing keys. Is this specific key available somewhere, or should I just machine a piece of 1/4" stock down, or is this going to be a bear and it needs to be hardened tool steel?

07-22-2014, 02:49 AM
Modern tools seem to use plastic covers for the brushes and are only screwed in slightly more then finger tight. I doubt it will be a problem if you machine some 1/4" stock down.

07-22-2014, 09:48 AM
I find it very unlikely that you would need to remove the brush holders to disassemble? I have never come across that situation before. Normally once the brushes are removed the armature would be removed from the opposite end?

07-22-2014, 10:57 AM
Black Moons, this is NOT a modern tool!


Max, You see the brush housing behind the switch? the screw in cover that retains the brush goes into a threaded brass cylinder that extends out to engage the outer housing, acting like retaining pins, preventing the motor from being slid out the back after the back cover and retaining rings have been removed.