Bought at garage sale. Plugged it in and it acts at though it is bogged way down. Turn it off, and tried again. The rotation of the shaft switched, and continues to switch every time i turn in on and off. Any Ideas. Tested voltage, that fine. something the key i think, appears to be broken off the on/off switch
-- oldmanmcgee
See "runs backwards" and "motor hums" section starting on Pg 6. There's a relay in there, that probably has fried contacts.
-- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
I bought my saw new sometime back in the 1960's. If it doesn't get used for several years, it acts that way, or squeeks a lot. A good shot of WD-40 aimed at the bearings frees it up. I think your problem is usual for the old machine.
Paul
On Fri, 7 Sep 2012 01:26:56 +0000, oldmanmcgee put finger to keyboard and composed:
FYI ...
Instruction Manuals:
You can see the exploded diagrams at Sears, eg ...
- Franc Zabkar
-- Please remove one 'i' from my address when replying by email.
Amazing how much saw-dust gets in the switches of such saws , until breaking contact, probably the same for relays
I can see the mechanism for dust ingress to switches , not so much for relays. Switch-casings are not hermetically sealed and the internal pressure , inside the kit , transfered to the switch innards is probably negative with a spinning blade , and sucks in fine dust from the air outside.
outside.
The following >>is not
How about a model number? That will help locate a manual, and tell who made it for Sears. Emerson made a lot of their saws in the past. Does it have a run capacitor?
A bit more on the saw motor. The relay is inside the motor assembly. As I vaguely recall, it's an open frame relay. Some of the later saws used capacitor start motors and didn't have a relay. A few models have centrifugal switch contacts inside the motor. Whatever the configuration, tear the motor apart, clean out the crud, burnish the contacts, possibly replace the starting cazapitor (if present), and it should work.
My father had a 1960's vintage 10" Craftsman radial arm saw in the garage. It was an all metal heavy duty monster that was capable of launching a 2x8 through the garage wall when used improperly (by me). No safety devices anywhere in sight. I just loved dangerous toys and became rather attached to the monster. We never had a problem with it. Eventually, enough sawdust wedged itself around the motor armature that it began to smoke. Teardown and cleaning but it back into normal operation. It's still running today at a friends workshop.
Standard rant: No model number, no model specific information.
-- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
Radial arm saws usually have universal motors. Hard to see how one of those can run backwards. But, if it is an induction motor, a bad starting cap could certainly cause that.
Jon
Perhaps one should say "How the @#$ does the @#$@#$ dust get into the @#$@$# relays?"
Some of us prefer to utilize prognostications suitable for Scrabble.
Others not so...(ducking).
John :-#)#
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It's probably an induction motor (if it were universal-motor type, it wouldn't run in reverse). So, it might be the kind with a centrifugal switch for starting. Probably it just needs the switch cleaned of accumulated sawdust.
The switch is (usually) operated by a pushrod next to the motor shaft, inside the motor bell housing.
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