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Milwaukee Super Sawzall Intermittent Stopping

renata

Sep 10, 2018
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Sep 10, 2018
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Hi. I have the 6527-21 model (corded) and it has taken to slowing and outright stalling. A lot. Doesn't appear to be related to the load I'm placing on it (i.e. not only when I'm really pressing). Yesterday, it refused to even start for the first time ever (but later did so). Thought it might be a power cord problem, but that seems less likely since moving it around doesn't consistently fix it.
I should note that a neighbor borrowed it to saw apart his "crappy" pool table that he assured me was simply particle board. Nope. It's slate. The blade he used is shaped like a lightning bolt. Anyway, possibly related.
If this is fixable, I'll tackle it. Otherwise, I guess I'll have to get me one of the new Chinese models (aren't they all made there now?).
Thanx
 

duke37

Jan 9, 2011
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No idea what gubbins you have but if it has a universal motor then I would think that the brushes are shot and making intermittent contact with the commutator.
 

Bluejets

Oct 5, 2014
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Make sure it is unplugged, get a proper tool to remove one of the brush holder covers, remove the brush, peek inside using a torch.
Willing to bet commutator is all arced and burnt with arced out gaps between commutator bars.
When it would not start, points to an open coil on the armature.
If above, buy a new tool, parts will be more than a new one.
 

dave9

Mar 5, 2017
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^ I doubt a new one would cost less than parts. This is a high end contractor brand saw that, in today's equivalent model, would probably cost close to $200.

For example a $10 switch, $3 brushes, or $50 armature, except that in in a brief look, I didn't find anyone who still stocks the armature.

Definitely pull the brushes out, but if it comes to it, pull the whole thing apart and inspect all of it, and you can also at that point use a multimeter to see if the switch is working by measuring what is getting to the motor when its struggling.

It's possible you just need to take the motor apart, touch up the armature's commutator bars with very fine grit sandpaper, and clean all the slate dust out of it. For quite a while I've felt that higher end tools that generate fine particle debris should have an intake filter to block it from getting sucked in. Also check the bearings, that dust can get into them too if the seals are worn out, and the front end slide bushing (whatever it's called) could need flushed with solvent then relubricated.

Shorter version: Strip down and clean everything, reassemble and try it, and if it's still acting up, measure for power loss with it open and the motor disconnected from the gearbox. Depending on how much use it's had, that might be a good time to relube the gearbox too.
 
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dave9

Mar 5, 2017
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^ Cart before the horse? He came here looking to fix it and the next step is to determine what's wrong, THEN see if the part (if any needed) is available... not so different from fixing anything that uses unique parts.

In this case, it really is worth fixing (if possible) as it's not some low end junk product, quite the opposite. That is unless it was beaten up on a jobsite all day, every day, for several years so all the mechanicals are worn out.
 

Bluejets

Oct 5, 2014
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Already told you what's wrong with it given the description the Op gave.
Many parts are no longer available for this model anyhow.
 

dave9

Mar 5, 2017
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^ You have described one possible failure mode, then assumed parts were too expensive, and now assume not available when it may merely be a matter of searching a bit longer, "IF" it's a hard to find part, "IF" any part at all needs replaced.

If you would rather not repair tools then it seems you are opposing the intentions of the topic. They definitely do not all fail from a burnt up commutator. Mere brush wear-out could cause this for example, which is a known issue that eventually affects all brushed tools.
 

H2814D

Nov 4, 2017
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Nov 4, 2017
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Others have had issues with the power on/off switch causing your problem. Look at that as well.
 
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