Jet lathe 1221 reverse

[Paul Lajoie]

I was sanding a piece on my lathe last night and like I always do pushed the reverse button it hesitated for a split second then kept going forward. Now it will only run forward. I’ve read somewhere pushing the reverse button while going forward would not harm the motor or electronics. Anyone have this problem? Haven’t had time to take power box apart yet, hope fully this weekend. Thanks for any info.

Paul

 

[Jim Selby]

From the online schematic it is a dc reversible motor controlled by a printed circuit board, most likely burned the pcb.

 

[Paul Lajoie]

Thanks for the response Jim. The lathe still runs forward so hope it’s not the pcb


Paul

 

[Paul Lajoie]

So this morning I went down in the shop for a couple minutes just to get a dose of wood fiber, flipped the lathe in to reverse and turned the lathe on and it ran in reverse!! I must have tried a dozen times since it first happened and wouldn’t run in reverse now today it does! Still planning on taking box apart and clear out, check the switch contacts. So it’s a good day

Paul

 

[Mike Johnson]

You may have some dirty switch contacts, a little contact cleaner may do the trick.

 

[Paul Lajoie]

You may have some dirty switch contacts, a little contact cleaner may do the trick.

That’s what I’m hoping all it is. Just don’t understand why it wouldn’t run in reverse for the two or three days that I tried. But I’m happy it is working, need to find some time to open it up and clean.

Paul

 

[Mike Johnson]

Exercising the switch numerous times will on occasion clean the switch contacts enough to get it to work, some contacts are made of metals that can oxidize over time or you possibly have carbon built up on the contact surfaces from fine wood dust finding their way into the switch enclosure. Wood dust is really fine particles almost like flour which can migrate into really small openings and crevices. Every time you turn a switch off and on an arc occurs between the line and load contact inside the switch assembly, this small arc consumes a small amount of metal and leaves a carbon residue behind, the better quality switches have a wiping function that cleans the contacts each time they are operated, the lower cost switches do not have this feature. Higher quality switches also use silver or gold alloys for the switch contacts that increase the life and reliability greatly.