New owner, old machine - did I break it already?

[AirWeaver]

Hi folks- brand new to the board.

First the background: early 80s Mark V. Bought from a friend two years ago, impeccably maintained for its whole life. I stored it in my basement for two years, finally put it together recently. I've had success using drill press and sanding functions. No issues with the machine.

Then tonight, I decided to finally use the table saw. I just wanted a rough cut of some thick plywood I had. So I put on the blade that came with my purchase, secure in the Mark V arbor. I did one cut that went rough, turned it off and looked at my speed. Seemed low. So I increased the speed. I ran the piece through again, but it slowed down, caught, and the blade stopped spinning. Afraid of kickback, I held the wood tight while reaching for the power off. So it took a few seconds to successfully power off.

I took the wood away and tried to turn the machine back on. Nothing happened at all.

I have burned out motors before, and smelled the evidence. There was no smell here. But that could not have been good for the machine.

Power supply seemed unaffected. As in, I didn't blow out a breaker or anything.

So what did I just do? Did I just ruin my powerhead? Am I missing some kind of reset button or switch?

Any help in diagnosis is greatly appreciated.

Andy

[trjohns22]

You probably trip a breaker. Check your power box. Also what type blade are you using and is it sharp?

[AirWeaver]

The power is still going to the outlet I had it plugged into. Is that evidence I didn't trip the breaker?

As for blade.... a very old shopsmith brand one with not that many teeth. Probably not that sharp. I just wanted to do a couple rugh cuts that didn't need to be nice and smooth.

[moggymatt]

Did the motor stop along with the blade? Or did you turn it off because it was still humming but not spinning?

[JPG]

Broken motor belt or poly-v belt broken or slipping?

[Hobbyman2]

With it unplugged can you spin the blade by hand ?

If it spins an you feel the belt ?

[br549]

Am I missing some kind of reset button or switch?

No, there is no kind of reset button of which I am aware. And the fact that you don't smell a burnt motor is also a good sign that you haven't ruined anything. Since you got your machine, have you done a thorough cleaning inside of the headstock and motor? My machine occassionally will fail to start when the centrifigual switch inside the motor gets stuck due to sawdust buildup. Just blowing and vacuuming inside the headstock is usually not enough for me, and I take out the motor and open it up to clean it and that has always fixed it for me. I usually have done my heavy dust producing operations outside and just let the dust fly, and that probably didn't help with the amount of dust that got sucked into the headstock and motor. I am now trying to be more diligent about hooking up my dust collector, even when using outside, just to limit the amount of dust that gets into the motor.

It is possible that your power switch just happened to fail at the same time, or maybe some connections came loose.

My machine is of the same vintage, and I have on occassion bogged it down while making a heavy cut. A slower speed is actually better than a faster speed when doing a heavy cut, say in "L" speed range.

In addition to the questions which others have asked, does the motor hum when you try to start it?

[algale]

Once you diagnose the reason(s) why the machine won't turn on, it's time to diagnose the reason why the saw bogged down. Yes, could be a dull blade. Also could be lack of alignment of the fence/table (assuming you were performing a rip cut) also could be worn or improperly tensioned belts.

[JPG]

With it unplugged can you spin the blade by hand ?

If it spins an you feel the belt ?

It should not 'spin' unless the poly-v belt is broken.

It should rotate with belt drag and motor inertia if both belts are NOT broken.

The idler shaft should also rotate if the poly-v belt is NOT broken.

I would select something else rather than the saw blade for rotating the quill shaft(face plate or sanding disk).

Airweaver, you still with us?


Indeed we have not determined the symptoms - hums / tries to rotate / belt slip screech / ...

Total nothing leads to suspecting a faulty switch or loose wire.

BTW were you using either the miter gauge or the rip fence when attempting to cut that plywood?

[wa2crk]

Hi and welcome. Don't know what is causing your problem but it sounds like a switch failure. Switches have a habit of failing abruptly. The slowing and binding are most likely due to belt slippage. Unplug the machine and install the sanding disc instead of the sawblade. NEVER PUT YOUR HAND THROUGH THE INSPECTION PORT WITH THE MACHINE PLUGGED IN. Lethal voltages lurking on the rear of the switch.
If you don't smell anything like burned varnish the motor may be OK. Remove the motor belt from the motor sheave (pully) and try to start the motor with no load. If it runs you can breath a sigh of relief. If not take a deep breath and check all of the wiring
There were some wiring problems with GE motors that were sent to SS. I have an early 80's machine and the original leads to the motor from the switch looked like this

old wiring.jpg (80.35 KiB) Viewed 7426 times

If the motor runs it is fixable. If the motor is toast it is still fixable just more costly!!!!
Bill V