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General Category => General Scroll Saw Talk => Topic started by: saw dust john on February 28, 2011, 03:44:26 pm
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my dewalt 788 just goes click click click when I turn it on. sometimes the arm will go up and down a little. I was told my "someone" I need a new motor.
They cost about $238. not sure it's worth it.
any comments on above?
TIA
ps
new bushings, new switch, new fuse and holder.
looked at circut board on switch--looks ok, who's to know.
started same thing, so I can't beleive it's the switch, arm moves up and down a little, while noise comes from motor.
I am wondering if there is something slowing the arm down, I think I might have to take it apart, not looking forward to that.
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Check the condenser or brushes
Jimbo
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Hi, Tia! :D
Jimbo's right, but I'd suggest getting an Excalibur.
Bill
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When I had a dead saw, someone on here told me that the motor can get "stuck" and a good hit will help. Mine ended up being a switch, so beating on it didn't help me, but it did help with the stress ;)
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took the thing apart, pulled the motor. I cut the end off of an extension cord and ram the end into the quick crimps on the end of the clamped down motor. Motor ran fine, so I guess it good.
What's next the circuit board? How does one test that a new one cost $80.
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Hey John, Try the switch thing. Use compressed air and blow out the switch from the top. If that doesn't work, remove the two wires from the switch after you unplug the saw. Tape the wires together, then plug the saw back in. If it comes on, its the switch. I will explain how to disassemble it latter. If it doesn't, then it must be the circuit board.
OK, I just re-read your PS. You have installed a new switch. Only two things left. The speed control, and the circuit board.
How old is your saw?
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type 1
I don't know the age other than that.
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FIXED!
Ok, gathering all the advice from a couple of forums, I decided not to by pass the circuit board.
So first I thought I would put it all together again and start fresh.
The thing works great.
No problems, speed control is perfect.
Now why was this happening. So I started thinking and when I took it apart, out fell a piece of styrofoam from the back end. I didn't think much of it, thought it was packed in holding something in place. Didn't know where it came from, so had no way of putting it back to what it was holding.
So I am thinking that it fell apart and lodged up against one of the arm and was causing so much resistance that it slowed the saw down to barely moving.
last question:
do new brushes make more noise as they are flat and haven't conformed to the rotation of the motor?
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What!? no duct tape?!
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I could be wro uh mistaken. LOL
But I think it would be a good idea to run it without a load (not cutting wood) for a while to allow the brushes to conform to the arc. As they shape they also allow more of the brush to make contact which will reduce electrical resistance and the motor should run cooler.
Just a thought, it might not be all that important, but that's what I would do. It sure wouldn't hurt.
Gabby
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Yes brushes do make a funny noise until they are "run in". I learned this from rebuilding motors on r/c cars. I guess the best way to run them in would be run the saw at a slow speed under no load for a while and check the brushes for the wear in pattern.