My Band Saw Would Not Start But Now It Does

[terry_g]

Yesterday I went to use my old Walker Turner 16" bandsaw. I flipped the power switch and the motor started to pick up speed but it seemed slower than usual and did not get up to full RPM so I shut it off. I opened the covers and turned the wheels by hand and they were free. So I flipped the power switch on again and it started up but was gaining speed slower this time and then it tripped the 15 Amp breaker in the panel. The 14 gauge three wire cable going from the switch to the motor was warm to the touch.


The motor is a 110/220 1.5 HP 3450 RPM Wagner Leland motor wired for 110 volts. I took the cover off the starting capacitor and un soldered it and tested it. The capacitor was a Mallory made in Canada and 540 mfd. My tester said 542 mfd. So I reinstalled it. I took the cover off where the power wire goes in and made sure all the connections were tight and they were, so I took the belt off and turned the power on again. Motor ran up to speed right away, I let it run for a couple minutes with no problem. I shut it off and put the belt back on and turned the power on again, It spun up to speed like it normally does. I made a few cuts with it and it seemed to have the power it always had. Shut it off and restarted it several times without a problem.

What is going on? The starter switch not disengaging should not trip the breaker that quickly should it. I don't trust it now.

 

[djberta]

Possible connection issue. Corrosion on motor components. If it has been some time since you used the bandsaw, could be if it has sat for some time the bearing grease has gone hard. Same for the bearings in the motor. Even the belt being tightened to much and or going stiff can cause some issues. Possible as well sawdust in the workings but you shop looks really clean so may be not that. As you got everything running and going I would lean towards it being just everything being stiff.

 

[PeterT]

I assume it has a centrifugal switch? If so did you examine that the mechanism is operating smoothly & the contacts look clean, no welding or debris?

 

[terry_g]

I never took the motor apart. I just removed the two covers.
I'm thinking that is the next step,it could have accumulated a lot of sawdust over the years.

 

[trlvn]

... it tripped the 15 Amp breaker in the panel. The 14 gauge three wire cable going from the switch to the motor was warm to the touch.


The motor is a 110/220 1.5 HP 3450 RPM Wagner Leland motor wired for 110 volts. I took the cover off the starting capacitor and un soldered it and tested it. The capacitor was a Mallory made in Canada and 540 mfd. My tester said 542 mfd.

To be clear, you didn't mention any sparking, burnt smell or smoke. There was none of that?

Does the data tag on the motor indicate full load amps? Typically it will be in the range of 18 to 22 amps @ 120 volts for a 1.5 HP motor. Of course, it will draw much more when starting due to the inertia of the 16 inch wheels.

Since the capacitor is OK, I would think that @djberta has nailed it. Just the lubrication getting a bit stiff; maybe the belt too.

Your circuit is a tad undersized compared to the motor. Is the circuit powering anything else? Do you use the saw for heavy re-sawing or other demanding applications? If so, you might want to move it to a 240 V circuit. Replacing the belt and bearings is usually not too expensive and set you up for another couple of decades of service.

Craig

 

[someidiot]

Btw, that thing's gorgeous.

 

[PeterT]

I never took the motor apart. I just removed the two covers.
I'm thinking that is the next step,it could have accumulated a lot of sawdust over the years.

AI did a better job than me explaining how a faulty/dirty centrifugal switch could explain your symptoms. I'm not saying it IS the cause, but for sure I would check it. Otherwise your next mis-start might blow the capacitor and/or start cooking other things including the windngs.

 

[terry_g]

There was no sparking or burnt smell. The tag on the motor says Amps 16/8, I am assuming that is 16 at 110 volts and 8 at 220 volts.
When I bought the saw it had a metal blade on it and a misting system. I think it was from a sign shop. It also had a 3 1/2" pulley on the motor and a very high blade speed. I chucked the motor pulley in my lathe and made it a 1 3/4" pulley. It had no problem starting the saw with the bigger pulley.

I am going to remove the motor and inspect the centrifugal switch and contacts. and replace the bearings. I don't want to loose the motor or have it fail when I need it.