My Hummel belt sander works great, except when it shuts down unexpectedly! It's worse in the summer months, but it happened again yesterday. I had a 50grit belt on with the spring tension in the middle position. Had done one pass on probably about 600 sq. ft without stopping, when the thing just shuts down like somebody pulled the plug.
If I wait 10 minutes or so, she'll start right up again and go a while, and then that happens again.
Drives me crazy. Is there a thermal switch in there that cuts out after it heats up too much?

I had that happen with mine although it was within a one week span of it shutting down randomly. It turned out to be the run capacitor.
I believe it was about $80 and took me 10 minutes to change it out. Make sure your machine is unplugged.

ok, thanks.

The machine does have a termal shut down circuit .So the machine is not malfunctioning but as mentioned, the reason it is shutting off the machine is that your run capacitor is worn out and needs to be replaced.

The run capacitor should last 10 years or more if the machine is used properly but mine burn out in 6 or 7 months. No one can give me an explanation as to why my hummel is doing this since I run it correctly.

I'll order one up. Where's the best place to do that? I don't see any for $80. More like $150-$180.

I always buy mine through my main supplier who always has hummel replacement parts in stock. Any pro supplier that carries Lagler machines should be able to do that for you . And yes, they cost closer to $150.00 .

Typically the reason a run Cap goes down is current deficiency. Using a booster box should level the current from the box so you do not fry your machine.

this. your cap may also be fine. many homes have current ranging from 208 to 255 volts. use a booster. this will lower or raise the current and keep it at a consistent level.