milwaukee 9" grinder

Date 03-30-2009 13:23 Edited 04-01-2009 13:10

I have a milwaukee 9" grinder that I'm having a problem with, maybe someone can help.
It does not seem to come up to full speed any more and you can see alot more sparks from the vent opening on top of the housing where the brushes are. I do not know if that is related in any way but I would like to make this grinder work like it used to. Any suggestions on troubleshooting?

rs

Well, I cannot find any brushes right now, I may have to order some. I had a another one just like it for spare parts but after taking that one apart it was really worn. Probably why it stopped working. I will more than likely have to buy a new one. I have two 4 1/2" dewalt grinder & buffer that I use most of the time anyway. It's just nice to have the larger 9" grinder for other applications.

thanks guys

By tazmannusa (**)

Date 03-30-2009 14:00

New set of brushes and clean up armature if needed.

By RonG

Date 03-30-2009 14:11

If you think it's worth your time and expense, Turn the Commutator and replaces the Brush's and Bearings.

Turning the Commutator requires removing the Armature and machining the Commutator (you'll need access to a small Bench Lathe).

After that you can take an old Hack saw blade (grind the set off the teeth) and use it to cut the mica between the bars down a little. Smooth with non-conductive emery paper.

If the rest of the machine is sound (right angle gear head & frame) it should work as good as new.

By NMWELDING (**)

Date 03-30-2009 15:04

I had a couple of Metabo grinders that did the same thing about a year ago,not sure if yours is the same problem ,but it could be. I was told to blow out the grinders with compressed air every now and then to clean out any grinding grit that may get in there. Blow it off the armature and brushes. I did this and mine have worked OK since.

By DaveBoyer (*****)

Date 03-31-2009 03:17

If You still get a lot of arcing after servicing as Ron G suggested, there is an open set of windings in the armature, and that is usually not a cost effective replacement.

By Stringer (***)

Date 04-01-2009 02:01

Grinders break gears, switches, brushes and burn armatures and cords. My advice is to keep to a model and brand you like (if only the company will keep making them) and save all your dead grinders for parts. Compressed air is good, but my favorite solution is to get someone else to do all the grinding.

By stkwldr (**)

Date 04-01-2009 13:13

Your right on getting someone else to do the grinding, but I work alone all the time. So when the grinder comes out, I'm first in line to use it.