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PM 4224 On-Off

Posts

PM 4224 On-Off

#1

PM 4224 On-Off

Don Stephan

Don't know how others work, but when making once turned bowls from log blanks I stop and start the lathe a lot. On the outside, I am checking progress on bark removal and looking for defects in the wood. On the inside I'll feeling for ridges and checking wall thickness.

Last week I noticed that rotation of the spindle would often be delayed a few seconds when I pulled the on/off button back out. Yesterday I thought I'd avoid the on/off button by simply turning the speed dial back to zero for an inspection, then back again. The 3rd or 4th time I did this the machine would not spin up again until I pushed in and pulled out the on/off button a couple times.

Can anyone advise if the above represents one problem or two, and possible causes/fixes? I didn't expect PM tech department would be open Saturday afternoon, but I will try to contact it tomorrow.

Thanks.

Re: PM 4224 On-Off

#2

Re: PM 4224 On-Off

john lucas

Sounds like a dirty switch or possibly the Potentiometer that controls the speed. First thing I'd try is blow it out. If that doesn't work then get some electronic cleaner spray and spray them both. Don't know it the 2442 has the same switch as the 3520 but the main on/off switch is a micro switch controlled by a larger mechanical button. You could also have loose connections somewhere. Check to see if all the connecting wires are snug (make sure the lathe is unplugged). The connections on the inside of the Variable Frequency drive some times come loose on the Powermatics. Remove the cover and tighten all the screws that hold the various wires from the on/off and variable speed controls. Hopefully some of those will help you.

Re: PM 4224 On-Off

#3

Re: PM 4224 On-Off

Dwight Rutherford

Wood dust can cause this to happen. I'd open the door on your headstock and give a shot of compressed air to the back of the stop-start switch and the speed pot.

Re: PM 4224 On-Off

#4

Re: PM 4224 On-Off *LINK*

Doc Green

Chances are it's the switch because operating the switch caused it to spin up again. These switches have a history of failure because they do not snap and because the voltage being turned on and off is very low.

Fortunately, the switch is inexpensive (not from PM) and easy to replace. Details are given in the following link.


PM Switch Replacement

Re: PM 4224 On-Off

#5

Re: PM 4224 On-Off

mikeee12345

Make sure you verify the make and model of the switch contact block.

Manufacturers tend to change part numbers and make and model of parts

in their quest to provide "value" to the customer.

On occasion the manufacturer of the components may also obsolete and

replace the old style switch with a new style switch to compete in the market.

Re: PM 4224 On-Off

#6

Re: PM 4224 On-Off

John K Jordan

I've had the switch fail when very fine sawdust got inside. I disassembled the switch (watch out for a tiny steel detent ball that might pop out), cleaned, reassembled, and sealed before reinstalling. Has worked perfectly since.

JKJ

Re: PM 4224 On-Off

#7

Re: PM 4224 On-Off

mikeee12345

Fine wood dust when exposed to an arcing switch contact will turn to carbon over time.

Carbon dust conducts electricity and can easily create issues in an electrical circuit.

A clean switch contact is a happy switch contact.

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