Shaper Adjustment PM 25A

[Glen Butler]

I have a powermatic 25A. I installed a brand new freeborn raised panel cutter and made a sample cabinet door for my client. When the door was all made I noticed a blemish in the cut running the length of the cut. Upon inspecting my knives I found one had the ever so smallest chip in it, but I thought since there are three knives the chip would have to be on all three knives for it to stay there. It turns out that the knife with the chip is lower to the table by a few thousands than the other knives, but every knife is different.

The instructions for the cutter said to tighten a straight edge into the spindle lower it while spinning by hand to determine that the spindle is running true. Seems to me even if the spindle was tilted each knife would measure the same at the same point on the table. True? So it seems that either the knives are not in the head correctly (this is an insert cutter) or the head is not perfectly square to the spindle. How do I correct this? Specifically the head no being perfectly square to the spindle. This freeborn instructions said to shim it but where would you put the shims?

[J.R. Rutter]

I would swap the inserts around in the head, making sure that everything is clean and the knives are pressed against the registration points. It is certainly possible that they were not meticulously installed.

The spindle gets shimmed square to the table by finding out how it is mounted and putting shims under the attachment point(s) as needed. This will not affect the cut from your raised panel cutter, but will improve the fit of mating profiles like cope and sticking.

[Peter Quinn]

Ditto what J.R said. I ran a Delta shaper whose spindle was out of square for over a year, never noticed as I was running moldings or stacked door sets and I was able to shim them to work. I started making passage doors with an Amana profile pro set, and you can't shim those insert knives. I was out by .040" tongue versus groove as all errors were doubled, and that was a problem. I had to loosen the bolts that hold the entire yoke assembly to the table and slip shims from McMaster Carr under the contact points in a sort of hunt and peck method. Not the most fun I ever had, don't know how it works on your machine exactly. But this should not be a problem for raised panels.

I can tell you that it doesn't take much dust to throw off the insert heads locators. I have a Freud RP2000 (2 knife panel raiser), and I have to clean it meticulously for proper results.

[Glen Butler]

I disassembled the stack and checked the spindle for squareness it seemed dead nuts on. So I cleaned every piece in the stack as it was reinserted and all my knives are within .0015. Sadly that one knife with the knick was still lowest. I could have switched postitions but as it arrived damaged I just called my distributer and he had it switched out within two days.

[Peter Quinn]

Did the new inserts solve the problem? If so great, because shimming a shaper spindle assembly is not the most fun I have ever had. I set my amana profile pro knives with a magnetic base dial indicator now referencing off the table with the cutter block secured to the spindle. There was enough margin for error in knife alignment to annoy me. Once I get a set of knives set they stay set for the duration of the job.

[Glen Butler]

Yes the new insert solved it. My panels are coming out perfectly now.