# excalibur 21 brush in the motor. what size? Thanks



## excalibur 21 user (17 Feb 2015)

Hi, new to the forum. My saw not working  so the guy suggested changing the motor brushes.
Can someone give me the exact size of the brushes needed for this machine so I can order some from
ebay. Are they 6mm x 6mm x 15? They have lots of similar sizes so im not sure. Cheers peter


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## scrimper (17 Feb 2015)

I would check the brushes first if you suspect them but if the saw stopped suddenly or would not run it's doubtful the motor brushes are worn out. There are many things to stop a motor working and the brushes are the last item that I would normally check, generally speaking carbon brushes last a very long time and if they wear out really quickly it's because of shorts in the armature windings causing poor commutation and excessive sparking wearing the brushes out, but you would most likely notice by a burning smell and erratic running.
Occasionally one brush will stick in it's holder eventually losing contact with the armature as the brush slowly wears down.

Before ordering brushes or anything I would first check for a wiring or switch fault or a fault in the speed control.

The above comments apply to any scroll saw and motor, I have no knowledge of the Excalibur saw.


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## excalibur 21 user (17 Feb 2015)

Thanks for the info scrimper, the glass fuse in the machine blew as this happens sometimes. I would just get a new fuse and everything is fine again for a few months but this time it wont work.. I have tried a new setup with new fuses,plugs and leads etc. I have a multimeter but am a bit worried about testing the switch with it so thought I would try new brushes first. The brushes I removed look fine, they had some black on them but that could be rubbed off. Cheers


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## scrimper (17 Feb 2015)

excalibur 21 user":baase6m7 said:


> Thanks for the info scrimper, the glass fuse in the machine blew as this happens sometimes. I would just get a new fuse and everything is fine again for a few months but this time it wont work.. I have tried a new setup with new fuses,plugs and leads etc. I have a multimeter but am a bit worried about testing the switch with it so thought I would try new brushes first. The brushes I removed look fine, they had some black on them but that could be rubbed off. Cheers



If you have a multimeter you should have no problems with testing. with the saw unplugged just test the various circuits for continuity but bear in mind that for proper testing you often need to disconnect an item otherwise it's possible to get a parallel reading and send yourself on the wrong track, find the leads that go to the motor and disconnect one of them (to avoid a parallel reading) then check for continuity across the motor, if there is then you can rule out the motor being faulty. same with the switch etc.


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## Bryan Bennett (17 Feb 2015)

Hi and a very warm welcome to the forum,I see that you have had a reply from John and suggestions have been made.I hope that you can soon sort out the trouble :roll: 

Bryan


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## excalibur 21 user (18 Feb 2015)

Thanks for the welcome Bryan, yea hopefully i get this sorted soon. Im using a cheaper scroll saw at the minute and its driving me nuts ,lol. thanks Peter


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## excalibur 21 user (18 Feb 2015)

scrimper":zypjk20s said:


> excalibur 21 user":zypjk20s said:
> 
> 
> > Thanks for the info scrimper, the glass fuse in the machine blew as this happens sometimes. I would just get a new fuse and everything is fine again for a few months but this time it wont work.. I have tried a new setup with new fuses,plugs and leads etc. I have a multimeter but am a bit worried about testing the switch with it so thought I would try new brushes first. The brushes I removed look fine, they had some black on them but that could be rubbed off. Cheers
> ...



Great scrimper , Ill have ago at this. The Excalibur sales guy says they need to order new brushes and can take eight weeks so im not sure i can wait that long,lol. I thought i could just get them from ebay. I was considering getting a new machine and keeping the other for spares but the Excalibur price has went upto to about £700, was only £490 when i got mine about 4 years ago.. Anyway thanks again,you have been very helpful. Ill report back if any luck. thanks Peter


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## Dominik Pierog (22 Feb 2015)

Hello excalibur 21 user

Its EX-30 user here. Guess what happend yesterday ?






I check size 6,3x6,0x15,0 mm 

I found and order similar Black&Decker 376143 6,0x6,0x15,0




So in this week I check if it fits.If I receive it of course.


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## excalibur 21 user (24 Feb 2015)

Cheers ex 30 user, lets know what happens, hopefully your up and running again soon.

My multimeter was broke so i havent got round to fixing anything on my machine yet


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## scrimper (24 Feb 2015)

Tip for anyone needing carbon brushes, if you have brushes that are a little oversize just file them down on the sides a little using either sand paper or a file. make sure the brushes run freely in their holders without being so loose that they flap about. If a brush is too tight it will eventually wear down and loose contact with the commutator resulting in erratic running or not running at all.

Some brushes have copper wires embedded in them to improve connection and generally speaking these are better, however if you can only get the ones with just the springs they will work OK but under heavy current the springs may lose their tension and result in poor connection to the commutator though this is rare on smaller motors and generally the non wired brushes wok fine.


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