My Jackassery

sed156 | Posted in General Discussion on September 28, 2020 02:21pm

Hey all:
I purchased a Laguna Platinum series table saw about 7 years ago. At the time, it was wired for 110 v because my garage did not have 220 outlets in it. I used the saw for about two years before putting it into storage after selling my house. After cleaning it off and setting it up in my new house, I notice the saw is bogging down even running 3/4 “ MDF through it. Now to my jackassery. Not knowing it at the time, I had my table saw plunged into an insanely long extension chord at my first house. I have also become painfully aware with the damage I could have done to the motor by doing this. I replaced the belts recently and plan on wiring the saw to a 220 v outlet. My question is, do you think my saw is salvageable, or have I damaged the motor to the point of no return?

Replies

john_c2 | Sep 28, 2020 03:06pm | #1
I don't see how a long extension cord would have damaged the motor. Damage the extension cord, maybe. Frequently trip breakers, sure. But not damage the motor.

Most likely the sitting unused for 5 years did something. Bad blade? Alignment of fence and blade way off? I would check all of those things. If you have a 220 volt outlet already set up, go ahead and rewire the motor.
harrisdog43 | Sep 28, 2020 03:31pm | #2
Long term use of an improperly sized extension cord can cause motor damage. My experience is that the bearings need to be replaced. I bought two bandsaws that were run using 18 gauge cords, I use 12 gauge today.
sed156 | Sep 28, 2020 03:33pm | #3
From what I’ve read, the heat generated by the conductors in the motor is related to the square of the current. If the extension cord causes a voltage drop the motor heats up quickly. I have a brand new blade in the saw and my fence Is parallel to the blade, so nothing is pushing against it. I also cleaned out the inside of the cabinet and lubricated the gears with a Teflon spray.
john_c2 | Sep 28, 2020 03:51pm | #4
But, I assume the saw was running fine 5 years ago, when it was used last. So the motor wasn't damaged then, from the cord use. So it's something that has happened between then and now.
sed156 | Sep 28, 2020 04:02pm | #5
It sat in a storage facility for 2 years and then my mothers garage for another 3. It had a decent amount of rust on the top but was easily removed with some wd40 and some elbow grease.
gulfstar | Sep 28, 2020 04:13pm | #6
I calculated the voltage drop obtained by using 100ft of 14 gauge extension cord on a 3 hp motor at full load, about 20 amps. It amounts to 10 volts, within the usual 10% voltage variation a motor will go through without damage. If it is the same Leeson 3 hp that I have on my Laguna Bandsaw, it has a insulation class rated at '' F '' on a scale from A to H which is pretty at the top of the heat resistance qualities for a motor so no concerns there, it will have to heat up to 155C to breakdown, by that time the paint will peel from the motor casing.
mikeinohio | Sep 28, 2020 04:42pm | #7
I would have the centrifugal switch inside the motor checked out. Even a small amount of rust on the internal portion of the motor's shaft can prevent the switch from engaging resulting in low power, slow RPM and overheating.

There's lots of YouTube videos on this subject if you feel comfortable opening the motor yourself to clean and lubricate the switch.

Mike
sed156 | Sep 28, 2020 04:42pm | #8
It’s my understanding that a 10% voltage drop can cause about 23% increase in heat in the motor. Is that enough to cause serious damage? From what you posted it doesn’t seem like I have anything to worry about. I have the same 3hp Leeson motor in my saw too. My hope is that when I get a sub panel installed in my garage and the saw connected to 220 v this will fix problem. I started freaking out the more I read about how motors can be damaged with improper electric chords.
sed156 | Sep 28, 2020 04:48pm | #9
Thanks Mike, I will definitely check it out