I know, I know, the bandsaw crowd will be applauding:
Yesterday, my tablesaw all but died. I have a 10″ Delta contractor-style, open-stand tablesaw, about two-and-a-half years old. While I was using it, there was a flash of a few blue sparks that came up, a wierd sound that wasn’t metal-on-metal but that I can’t otherwise describe — except that it sounded like there was some variation in the RPMs — a whiff of electrical smoke and then it died.
After carefully pulling my half-cut piece off the blade, I checked the circuit breaker at the panel of my workshop. Blown. I re-set it and checked the circuit breaker on the heavy-duty extension cord. Also blown… I re-set it, too. The circuit breaker on the saw itself was NOT blown. After unplugging the tablesaw, I checked out the blade to see if there were any obstructions, also examining the belt and whatever I could see of the motor suspended underneath. Nothing seemed odd, so I decided to turn it on again, as a test — standing as far away and out of the line of fire as I could, while still being able to reach the power switch.
I didn’t see blue sparks this time, but it did sound a bit wierd and almost immediately konked out again. Both the extension cord and the wall-panel circuit breakers had blown, but again, the circuit breaker on the tablesaw itself was not blown.
I suppose I should call Delta first, but is there anything I should/could take a look at myself? I know next to nothing about small motors and electricity, I’ll readily admit, but it sounds/smells as if there’s a short somewhere. Does anyone have any ideas about what the problem could be?
I was able to finish what I needed to do on my bandsaw, and I built pieces for a long time without a tablesaw, so it won’t be anything more than an inconvenience for the time being. I bought the unit from Lowes, if that helps, and it’s certainly not a high-end model — I just needed something to do basic, utilitarian cutting. Can Lowes help, after all this time? Is this a sign that I should save my pennies and by a higher-quality saw?
Any suggestions are much appreciated.
David
“The world that was not made is not won by what is done” — Mundaka Upanishad
Replies
Sounds like you had a winding in your motor either burn out or go directly to ground. A whiff of smoke and blue sparks normally indicate this. This would cause high current, in turn cause your circuit breaker to trip. Not much you can do with the motor except replace it, as a trip to the motor shop is not economical. I imagine you have a 1-1/2 HP motor and you can easily purchase these for $100-$150.00, unless you go thru Delta and they may want two prices for their motor. If your motor mounts on the back of the saw it should be a fairly easy changout. If it was me I would sure replace the motor before I bought a new saw unless you are looking for an excuse to buy one. Hope this helps.
You said you owned the saw (and I presume have used it) for ~2.5 years. Out of curiosity, how often did you blow out the motor and mechanisms with compressed air?
Jon
You said the motor is suspended underneath the saw, suggesting it's a universal motor. Contractor saws with the motor hanging out the back have induction motors. Can you say for sure which it is?
It sure sounds like the windings burned, probably to each other, in which case you'd have to replace the motor. A motor shop would charge more than a new motor to rewind it, if they even could. If it's an induction motor, it has a standard frame (NEMA 56, probably), and new ones can be had all over the place for relatively little. If it's a universal motor, you will probably have to get the replacement from Delta. It may be more cost effective in that case to get a new saw. There is also a chance that the brushes have simply failed (universal motors only), and a replacement set could get you going, but I doubt it. If they're that far gone, the commutator is probably trashed also. Sorry.
Be seeing you...
Wow, thanks for the fast responses.
The motor hangs underneath the table, rather than out the back, so it sounds as if it must be a universal motor (sorry, I'm not at my shop, so I don't have the manual available to me at the moment). In which case, it sounds as if the consensus is that it's something I would have to get from Delta, and which might not be very cost-effective (if I include installation, which I'd have to have someone do for me, since I haven't worked much on motors and don't want to do my learning on this piece of equipment).
Jon, you asked a good question. I don't own an air compressor, but I do have a Penn State dust collection system, and I would fairly regularly vacuum out the underside, including as much of the motor as I could reach. On average, I probably cut just a few board feet of wood per week, and vacuumed it out every second or third week. Was that too little, you think? If I were (at some point in my life) to get a cabinet-style, enclosed tablesaw, do you still need to get in there with compressed air, and how often would you recommend?
Thanks,
David"The world that was not made is not won by what is done" -- Mundaka Upanishad
"I don't own an air compressor, but I do have a Penn State dust collection system, and I would fairly regularly vacuum out the underside, including as much of the motor as I could reach. On average, I probably cut just a few board feet of wood per week, and vacuumed it out every second or third week. Was that too little, you think?"
Honestly, I don't know. But after you yank the motor, why don't you let us all know if there was much dust inside it. I have a Delta Unisaw myself, and the motor is sealed, but still hit it with compressed air after ~ 1 or 2 hours of use. Plenty of dust comes out. Just seems odd for a motor to expire after 2.5 years of light use. I've seen plenty table saws that have been in daily, heavy operation for decades with their original motors.
Jon
I agree, it does seem odd that the motor died so young... I'm generally pretty careful with my tools, and have yet to have had a single manufacturing defect with any of my power tools (unlike the many reviews I've read here and elsewhere, where purchasers complain of shipping damage, broken or missing parts, etc.), so maybe it was just my turn.
I'll let you know how it turns out. Thanks again for the advice.
David"The world that was not made is not won by what is done" -- Mundaka Upanishad
Hmmmmm, I just bought a Delta portable tablesaw with the same type motor. Warranty is 2 years and I bought the Lowes insurance just in case for another year. Hopefully I won't have to do it. But I paid $100 for saw/stand combo. If it craps out before I guess I will be covered. Good luck.
DM
You may want to try http://www.surpluscenter.com . In the current catalog 278 on page 126 the are some "replacement woodworking motors". Item "D" is a 10 amp 110 v 3450rpm direct drive table saw motor. The item # is 10-1789 for $38.95. Worth a look. They also have new motors that are more than reasonable in price. Bought several things from them myself. Good luck.
Jimmy
as always I wish you enough.
If it's a universal motor, pull the brushes for inspection (saw unlugged, of course). They're not likely to be the problem, but since they're cheap and easy to fix, give it a shot.
"The circuit breaker on the saw itself was NOT blown" Interesting. When the issue of sizing circuit breakers comes up I am amazed how many of yall say to oversize the breaker and line, "just in case". Time and time again I see people recomending using 30 Amp 220v. breakers for 3 horse machines. The danger is that if something goes wrong (even pushing the motor too hard) you risk ruining the motor. By the time a 3 horse motor draws enough to trip a 30 amp or posibly even a 20 amp breaker it could cause major overheating, or a melt down. The arguement is always that the machines have a circuit protector on them, so it is OK. David and his saw have proved that is not always enough. Imagine if that happened to a Unisaw motor, $$$ !
David sorry about your misfortune. If the waranty is up, open up the motor an see how bad the damage is. A motor shop may be able to fix it for less than a replacement.
Check the warranty time that came with the saw, next check how you paid. If its gold visa or better you might be able to claim a warranty repair. So don't take it apart yet!
Buying with Gold or better Visa or mastercard often adds 1 year to the warranty at no charge!
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