Bed rollers adjuster?

[Myk Rian]

A couple threads on planers has made me wonder about an adjustment on a planer our wood group uses at the local school shop. This old PM 180 has planed everything we throw at it, although we do get a little snipe.
The lever shown is what I'm wondering about. What is the proper use of it?

[Rick Lizek]

That's the quick bed roll adjuster. It's designed to be lowered for the final pass or raised for planing rough lumber. In my experience as a service tech that lever is the cause of more trouble than it's worth. I typically set the bedrolls a few thousandths above the bed and leave it there. Waxing the beds regularly is your best bet against feed problems. Of half the service calls I've made to schools, waxing the bed took care of the feed problems.

That machine, if adjusted properly, will have no snipe. I would set the bedrolls properly and remove the lever or at least locate the .003" setting and mark it to be left there. Guaranteed someone will move or bump it. Folks don't understand cause and effect of that lever. Had one planer where someone bumped the lever and they started adjusting the upper feed rolls after the head which had nothing to do with the problem.

Once a planer is adjusted properly one should be able to change the knives and everything will stay the same if the knives are kept at the same height relative to the cutter head.

[Walter Plummer]

I dug out the maintenance instructions and parts list for the model 180 planer.In it it calls for the rolls to be set .008" above the table with the lever set to 0. When we rebuilt it in 1993 Powermatic`s tech told us the revised setting was .005". Since then I acquired a copy of a pamphlet called "Powermatic Troubleshooting Handbook" and .005" is still the number. Another possible cause of the snipe is pitch or "gunk" sticking to the rolls. Try cleaning them and make sure they turn free. I have even had chips knocked off the back of boards get lodged between the roll and the table. That is the best planer I ever used. With the knife grinder you get the knives in a good cutting circle and as good a finish cut as anyone could ask for. After you run the boards and stack them they "stick" together with almost a suction between them. You will never get that from carbide.