Hi, I have working on meat slicer my whole life and can help you.
What normally happens is this. The bearings in the knife hub (this is the unit that the knife attaches to and spins) is starting to fail.
The gear on the knife hub is made out of a fiberous material and the worm gear on the motor is made out of metal, so when the bearings start to fail and cause resitance in the hub, the metal motor gear starts to eat the fiber gear on the hub and eventually wears a big chuck out of it. Then the motor spins free and doesn't make contact with the hub gear.
How you can check if this is the problem is this. You need to keep the power switch on machine in the off position and turn the blade a 1/4 of a revolution. Then turn the machine on, what should happen is that the blade will spin some and stop again.
The proper fix for the machine would be to rebuilt the knife bearing unit and replace the hub gear, motor gear and hardware.
In regards to the Chefmate. This is a design flaw of Globe and I told them about this when the machine first came out! The know is on a steel shaft that goes thru the aluminum body. The steel shaft starts to corode and also rust, then it freeze in the frame. What has to be done is this. This assembly needs to taken about sanded, lubed and put back together. The best way to permently fix this is have a machine shop machine the frame out and install a Oilite Bushing, these are impregnated with oil and it will never lock up again.
Where are you located? Let me know if I can answer any other questions for you.
If you have any other questions, you can call me on my cell 201-274-6274 or e-mail me at firstname.lastname@example.org
. Thank you