dead Milwaukee drill

[Mcgyver]

my 3/8 Milwaukee drill gave up the ghost tonight. Hammer function ceased a day after the warranty expired but it kept drilling for several more years . Tonight it slowed down, lost most of its power and the normal tiny blue sparks you could see were very bright, like a small lamp, on one side. Then the light went out (when i released the trigger). It was a plug in type. The worm drive saw paused in a moment of sorrow then carried on.

Is there anything servicable here, or should I just kijiji it?

[J Tiers]

If it also now has some times when it won't run, and/or if the blue sparks were apparently following the commutator around as it turns, making streaks when you look at them, you may have an open coil.

Since you are a persistent sort, you might take it apart and look at the rotor, and see if you can determine with an ohmmeter whether all the commutator segments have the same resistance to each other. What you describe is somewhat like the effect if one coil opens and is not connected to its commutator segment. The segment with the highest resistance, different from all the others, will be the one with the bad wire.

if you can spot the "open", and get at the ends of the wire, a soldering iron, a bit of wire to mend the break, and a dab of epoxy can bring it back. It is pretty common for the break to be in the part that extends down to the commutator. Sometimes the wire actually comes loose from the commutator, which may be easier to fix.

Unless it is for some reason special, a break elsewhere invisibly hidden in the coil, is grounds for scrapping it. Unless, of course, you have another one that has an unrelated problem and which contributes parts..... (yes, I am a "fix it as the first and best choice" person, even when it isn't necessarily reasonable to do)

[SGW]

Maybe it just needs new brushes?

[Mcgyver]

you might take it apart and look at the rotor, and see if you can determine with an ohmmeter whether all the commutator segments have the same resistance to each other. What you describe is somewhat like the effect if one coil opens and is not connected to its commutator segment. The segment with the highest resistance, different from all the others, will be the one with the bad wire.

thanks....if nothing else i might learn something. kijiji sale will take more persuading though if its just a box of parts

Maybe it just needs new brushes?

you may be right, I didn't see the screw on covers for brush replacement...will see when its apart

anyway I'll try and get it apart, take some pics and see

[Jon Heron]

My 1/2" Milwaukee hammer drill (POS) to my surprise had spare brushes and plastic cap crews in the handle of it.
Good luck!
Jon

[Bill McLeod]

one thing about Milwaukee is I can afford the parts, they are reasonable.

[JCHannum]

Higher end Black & Decker tools have the brushes manufactured such that they will not wear to the point that the commutator will be damaged by a worn brush. The tool stops before this point. I would suspect that Milwaukee would do the same. Check or replace the brushes before performing major surgery.