Author Topic: Dewalt chop saw  (Read 718 times)

Offline gldavison

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Dewalt chop saw
« on: September 15, 2022, 05:01:18 PM »
I have a Dewalt 14" metal cutting chop saw and the brushes are arcing excessively. I removed the armature cleaned up the commentator and reseated the brushes. I checked the armature with an ohm meter for opens and shorts, and check good. I also checked it on a growler and it passed those checks. The field windings and the armature windings show about 1 to 1.2 ohms.   And it still has excessive arcing.  :thinking:

I don't know how long new brushes are, but there is .4" of travel left before the spring bottoms out. So I assume (that get me in more trouble) there is enough pressure on the brushes.

 :help:

Gary
Windows 10 & 11, Alibre Design Pro V27, IntelliCADPro6, CamBam, Mach4, 3D Printers, Cetus, Anet ET5 X
15" South Bend, 10" Logan lathe, Grizzly square column mill, CNC router & Hot wire cutter. Lagun FTV-1 knee mill, Sherline mill & lathe

Offline cnr6400

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Re: Dewalt chop saw
« Reply #1 on: September 15, 2022, 10:37:11 PM »
One thing that might reduce arcing is to change to new brush springs (if possible and if available). They can lose temper from heating up while the motor is under load and passing high currents. When they lose temper, brush force is reduced and you get more arcing. Replacing springs has worked for me on many motors. Just a thought.
"I've cut that stock three times, and it's still too short!"

Offline gldavison

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Re: Dewalt chop saw
« Reply #2 on: September 16, 2022, 01:41:31 AM »
I had thought about that, but not sure if springs are available for this unit.
Gary
Windows 10 & 11, Alibre Design Pro V27, IntelliCADPro6, CamBam, Mach4, 3D Printers, Cetus, Anet ET5 X
15" South Bend, 10" Logan lathe, Grizzly square column mill, CNC router & Hot wire cutter. Lagun FTV-1 knee mill, Sherline mill & lathe

Offline Admiral_dk

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Re: Dewalt chop saw
« Reply #3 on: September 16, 2022, 12:04:42 PM »
Some springs you can 'Re-Tension' just by stretching them a bit ....
The delicate part is, that not enough - has no influence ....  :(
and Too-Much - ruins the spring ....  :Mad:

Per

Offline ShopShoe

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Re: Dewalt chop saw
« Reply #4 on: September 16, 2022, 01:48:04 PM »
gldavison,

You may be able to find replacement brush assemblies with springs and etc. You may find some for another application that are slightly larger than the ones you need.

You can make a brush smaller by sanding it on wet-and-dry paper on a glass plate.

I did this trick to make new brushes for a HF "hotdog" compressor that had stopped running reliably.

I always scrounge brushes from motors on things destined for the discard pile. Keep the springs and brush-holder parts too, if you can.

ShopShoe

Offline Don1966

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Re: Dewalt chop saw
« Reply #5 on: September 17, 2022, 01:55:15 AM »
Make sure the brushes are for that saw they make different grades of brushes some soft some hard. Use sand paper under the brush installed and seat the brush properly. If that fails yo may have a rotating short in your armature. Check the amps to see if it matches the name plate amps and not higher. If higher your armature is bad and it will heat up to the touch.

Regards Don

 

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