PM66 Problem

[Kevin Jaynes]

I have a mid 90's PM66 - I think it's a '97 model. When I lower or raise the arbor and/or change the bevel angle the blade will move left or right, and also become out of 90° by at least a half degree. Both of the below sleds are used for 90° work only. A picture is worth a bunch of typing . . .

The way the kerf should look . . . . .
294897

The way the kerf looks after the saw has developed this problem . . . . .
294898

You can see how far the arbor is moving from left to right. You cannot tell from the pic obviously that the arbor is also moving off of 90° to the back fence but it is. I know I'm going to have to remove the top and troubleshoot, but before I do, do any of you PM66 owners or past PM66 owners have a clue what I should be looking for? Or if not 66 ownders has anyone ever experienced this problem with any model saw?

[John Cole]

I will be following this thread closely - I have a PM66 with the same problem, although mine does not go out when I raise or lower the blade, only if I tilt it.
I have not had the time to tear it down and take the top off - for now I just got it aligned and kept the blade at 90 degrees.

I researched quite a bit and could not come up with a definitive answer as to what could be causing it.

[Chen-Tin Tsai]

My 1999 PM66 has this issue as well, although it doesn't change the bevel angle when I move the blade up or down. I've aligned it for parallelism to the miter slots as well as parallelism to the axis of tile for the trunnions. When I got it, there were no shims under the top, so it took several tries of reassembling the top, aligning the miter slots, and then checking for alignment at 45 degrees to figure out how out of parallel the top was in relation to the trunnions. Regarding the shifting of the blade, mine will move about 0.003" or so when raising it, but once it's raised or lowered, it keeps that setting.

I spoke with a technician at Powermatic about it a while back and he indicated that there were a batch of PM66's made in the late 90's that had a slightly misaligned hole in the pivot shaft hole of the bearing arm. This makes sense as the pivot shaft of the bearing arm and the hole for the arbor bearings have to be drilled absolutely dead parallel because if not, the action of raising and lowering of the blade would not be coplanar to the blade itself. Apparently, there were some PM66's that were sent back for warranty work, but the only way to fix it now is to replace the bearing arm. That part is on a long backorder, or so they told me. For me, after I went through the alignment process, it was such a small shift that I stopped worrying about it. I have found that going through the work of aligning the miter slots to the blade, as well as shimming the top (under the bolts) to ensure parallelism to the trunnion rotation axis greatly reduces any shifting.

[Ken Fitzgerald]

Out of curiosity, are you using a blade with the same kerf width all the time?

I built one of Norm's panel cutters and suddenly noticed it wasn't lining up with the edge of the blade any more. Then I realized, my cross cut blade though not a "thin kerf" wasn't as wide as the original blade which I was using when I built the sled.

[Kevin Jaynes]

Out of curiosity, are you using a blade with the same kerf width all the time?

Absolutely.

Chen, thanks for your informative post. I'm going to see what I can do to rectify this problem so I can sell this machine. I prefer older American made Iron but my wife wants to start using the table saw more often and as it stands I don't like her using it, so I'm going to get a sawstop so I have a little peace of mind. I've been wanting one for myself also anyway as I'm a bit careless at times and have removed some small pieces of my fingers over the years.

In the meantime I need to get this saw fixed because I'm not the kind of guy who could sell it like it is and sleep at night. Thanks for the replies.