tablesaw switch questions

[Renata]

Well, my vintage 1938 unisaw seems to want to keep running now that it's started being used again. It simply won't shut off.

First time it happened, I flipped the switch to off, and the saw kept running, but I immediately flipped it to on then off again and it stopped. Thus, I thought maybe I imagined the whole thing.

Happened a couple more times and then, last night, it simply stayed on. Had to unplug it. Plug it in, and it's off and running. Unplug it to stop. Whilst I'm gluing up the cabinet, I hear a from the direction of the saw (~4' behind me) but it's only noted in passing. But, when I next use the saw (say 10 minutes later), voila, it turns off via the switch!

Anyhow, I guess it's time for a new switch, non? I took the cover off and there was nothing notable that would seemingly interfere w/it's operation.

What was the click?

I'm thinking of simply running out to the nearest electrical supply place (no, not home depot) and getting a replacement. Any reason not to go this route vs the fancy, expensive one from Delta?

Thanx Renata

[Frank Boettcher]

Voltage?

[DonkeyHody]

The fancy one from Delta is magnetic. It requires electric power to stay in the "on" position. If the power goes off, or you trip a breaker while it's on, it won't re-start accidentally when the power is restored, even if you forget to turn it off.

The click you heard was probably the switch releasing itself to the off position after it got tired of having fun with you.

An electrical supply house should be able to fix you up with an appropriate switch without going to Delta. Take the information with you from the motor identification plate (voltage, starting amps, running amps, etc.).

DonkeyHody "We can't all be heroes, because someone has to sit on the curb and clap as they go by." - Will Rogers

[Markem]

I am unwilling to take a part my 1948 Unisaw switch, but I would think that the contacts in the switch itself maybe sticking, it maybe due to connection resistance causing heating and swelling, or dust clogging mechanicals. As to what is the best replacement for the old style switch with bullet motor, that will be information I need to file away for future use. Hopefully someone will be along shortly.

Mark (sixoneeight) = 618

[Frank S.]

[Andy Dingley]

Not just a switch, but a proper no-volts-release motor starter.

Also add yourself a knee-paddle off switch.

[B A R R Y]

You're going to need lots of wood!

[bent]

I had a very cheap plastic rocker switch get filled w/ sawdust. The sawdust physically prevented the conductor inside form moving to engage/disengage the alternate position on and off the electrical conductor points. I had to flip it on/off like craxzy, and it may or may not have done anything. After a while it burned the conductors away by flipping it. It was dangerous as far as there was no way to tell when or how it would recieve power. I do not know the schematics, or if there was any other serious electrical hazard.

[# Fred #]

One of the maintenance procedures is to exercise switches every few months or once a year to prevent it from sticking. Use it or loose it philosophy. Sounds like its just sticking and needed to be cleaned and lubed.

[bent]

I was actually able to take it all apart (outer housing/wires//switch/rocker conductor/gasket) to the basics, while the housing was still on the saw. Cleaned it up, and re-assembled with e- tape everywhere. I could re-use it only b/c it was a 110/220 and had duplicate rocker conductor spring bridges to the points, though one was fried, it still had spring function for the click rocker action. Just moved the outer wires from 0-110V to the 111-220V side. |_ to _|

if yours is different, magnetic, I know nothing. Be thinking of price, and if it is expensive, you may have options.

[bent]

it is common for switches to be plugged with sawdust, and can be aggravated when the sawdust is wet. The tiniest holes allow it in. It is like cleaning out a shaver of whiskers.

[bent]

with mine, it had to be taken apart, all the air for all the time in the world wouldn't work; elbow grease and a fine paint brush.

[Lew Hodgett]

Good game plan.

Look for the Allen-Bradley distributor in your area.

They tend to serve the industrial rather than the contractor segment of the electrical market.

Doubt you will find an exact replacement due to age, but you should be able to get a functional replacement with no problem.

Lew

[A.M. Wood]

No reason you need a delta switch. Probably better off with a good magnetic motor starter anyway. Much better than that old toggle switch.

Just curious though, since Delta only began selling The Unisaw in 1939, how did you get one from 1938.

[Mike O.]

If it has that art-deco style switch cover keep it. It does have some value to guys who are restoring those machines.

Mike O.

[George E. Cawthon]

I have an old heavy duty double pole switch on a jointer that my FIL gave me. Acted much as you described. Decided I need to buy a new one and installed it but still took the old one apart. The old one came apart easily and only needed needed some small pieces of wood removed and cleaned up to snap closed and snap open correctly. I kept the old one and am not sure if it isn't constructed better than the new one I installed.

[Renata]

-snip-

That's my little secret and if I tell you I have to...

I assumed (silly me) that since the serial number starts with "38-..." it meant 1938 plus the production run #. Guess I'll have to look it up, maybe on OWWM.

Renata

[Renata]

220V R

[Markem]

That would be 1945 model from OWWM serial number list.

Mark (sixoneeight) = 618

[Renata]

Oops - maybe I should get a new prescription.

It is indeed 39-2611.

Renata