Shopsmith won't turn off !!

[cousinwill]

My Shopsmith will not cut off unless I unplug the power cord. I thought the switch was bad so u ordered a new one. I put this one on and still the same results, machine will not stop unless the power cord is unplugged. I completely unhooked the switch and plugged the Shopsmith in and it still ran without the switch even being attached. Any suggestions or ideas ?

[JPG]

My Shopsmith will not cut off unless I unplug the power cord. I thought the switch was bad so u ordered a new one. I put this one on and still the same results, machine will not stop unless the power cord is unplugged. I completely unhooked the switch and plugged the Shopsmith in and it still ran without the switch even being attached. Any suggestions or ideas ?

Methinks we need to see how it is currently wired!!!!

Power cord black to ?????

Power cord white to ????

Power cord green to ???

[cousinwill]

Nothing has been changed on this Shopsmith. I've used it for 10 plus years without this problem. Switch worked just fine....on/off. This problem just appeared last week

[JPG]

Nothing has been changed on this Shopsmith. I've used it for 10 plus years without this problem. Switch worked just fine....on/off. This problem just appeared last week

It is a mystery to us also.

We need the answers to the three questions. For starters.

[BuckeyeDennis]

Just speculating here, but perhaps the switch was wired into the neutral line, instead of the hot line. Then, if the neutral line developed a short to ground last week, that short would bypass the switch entirely, giving the reported symptoms (assuming no GFCI).

[cousinwill]

I dropped the motor pan to get a better look at the wiring. Sorry I didn't take any pictures,but I can if it would help. It looks like the wiring gotten hot. The insulation around the wiring from the motor to the switch was partially melted.

[JPG]

Just speculating here, but perhaps the switch was wired into the neutral line, instead of the hot line. Then, if the neutral line developed a short to ground last week, that short would bypass the switch entirely, giving the reported symptoms (assuming no GFCI).

You snatched that out from between my ears!

Now the reason for the three ?? is revealed.

Assuming tis true, the ground wire may have prevented a shocking event!!!

[everettdavis]

I dropped the motor pan to get a better look at the wiring. Sorry I didn't take any pictures,but I can if it would help. It looks like the wiring gotten hot. The insulation around the wiring from the motor to the switch was partially melted.

It sounds like the black wires shorted together when they got hot and are touching, bypassing the switch.

If they were shorted to the case, it should trip the breaker (if you still have a properly functioning ground wire attached to the case, AND a grounded outlet.

I saw wires that fell down onto the worm gear and fused together like that once, and sure enough, there was a three prong to two prong outlet adapter that could not provide ground to the case when it happened, energizing the frame itself.

If the case has any possibility of not having the green ground wire attached and working properly through the properly grounded power outlet, powering the machine until repairs are made, should not be done. You or anyone else could receive a nasty even fatal shock.

Whatever it is, you can likely fix it by replacing the power cords and wiring going to the motor.

You don't by chance have one that someone has modified to be reversible do you? That wiring and switch also could be a source of your issue.

[JPG]

OK, which wires were being switched?

Which motor wire(S) were 'melted'?

I agree with Dennis, that the power cord black wire is connected directly to a motor wire(doesn't matter which one).

That means the remaining motor wire was being switched.

That motor wire is the one 'melted'.

Said melting likely extends internal to the motor.

Soft(melted) insulation allowed conductor to contact" the 'frame'.

Question remains what caused the initial 'melting'?

?????

My original ??? are still relevant and still unanswered.

[SteveB]

Just joined this forum because my 1954 Mark V has the same problem.

My 1954 model is so early, I don't have the access hole opposite the switch.

I live in the San Francisco Bay area. Anyone know of a local resource that repairs Shopsmiths?

Unit too nice to not get functioning again.

Steve