@difalkner Thanks for taking the time to check! It's good to know that there probably shouldn't be any play when lifting the arbor. I'm not sure that the gears could be off by one since it's it's a continuous mechanism and being off by one would essentially just mean the blade is one revolution higher or lower. I'm becoming more and more convinced that the gears just aren't fully and perfectly seated so there's a slight gap between the teeth that allows some slop. I've just gotta work at it some more to get the gear segment seated more snuggly against the worm gear.

It's nice to know that the cutout isn't intended to line up with the pully, even though it looks like it would be a good fit. Who knows why it's there, but this saw was manufactured for quite a number of years and must have seen many revisions that left behind no longer needed features.

Your second photo does seem to answer my question about the spacers on the pivot shaft. It does look to be metallic rather than the plastic washer I have. And the big nut holding it on is quite different than mine. My nut has a nylon ring inside it to act like a lock nut. Since they were inexpensive and I think the pivot shaft is the root of my blade alignment issues, I went ahead and ordered two spacers and a new shaft. The nut and retaining clip on the opposite side were discontinued, but I can get the clip at my hardware store and my existing nut should work just fine.

 

I restored my 1990 PM66 a few years ago but don't recall enough to steer you in the right direction. Here's my restoration thread if you want to glance through and see if anything will help you - Restoration - Powermatic 66 Table saw

 

@difalkner, Thanks doe sharing that thread. I actually came across your post the other day while doing some searching. Great work with the restoration. It does look like we have a similar vintage judging by the shape of the trunnion and the arbor pullies. Do you still use the saw? Has everything stayed nice and true over the years? I wonder if you recall any frustrations with aligning the gears for the raising mechanism or if everything just fell right in place?

Here's a photo to illustrate where my trunnion bottoms out when lowering the blade.

 

Great work with the restoration... Do you still use the saw? ...I wonder if you recall any frustrations with aligning the gears for the raising mechanism or if everything just fell right in place?

Thanks! It was definitely a lot of work but well worth it. Oh yeah, sometimes daily. Check out some of my videos on YouTube and you'll see it in use.

No, it all seemed to go together as designed with virtually no issues except for all the water damage.

 

@difalkner I don't think you'll be able to get a good look at that side of the trunnion from the throat. It's only really visible from the left side with the motor cover off. I'm not too concerned about the position of that cutout though since there's nothing I can do about it. It's well over an inch off of center with the pulley so any misalignment I introduced couldn't have affected it that much. It might shed some light in whether I have a Frankenstein saw on my hands, but I don't think that's the case.

I do wonder if you'd be willing to check if your arbor has any play when you lift straight up on it. That might inform me in whether I should be as concerned about the worm gears perfectly meshing.

 

I do wonder if you'd be willing to check if your arbor has any play when you lift straight up on it.

Just checked and there is no play whatsoever anywhere in the trunnion mechanism. I did find an old photo and in using a mirror on the saw just now it appears that when the blade is lowered into the lowest position the pulley does not directly line up with the relief cutout but it also does not hit the trunnion. These photos may or may not help...

Edit - maybe you're one tooth off on engaging the worm gear, if that's possible.

 

I have the same issue and was wondering if you found a solution to correct the slop in the raising shaft.

 

Backlash? I guess there's a tiny bit, not enough to be concerned with, though. Matter of fact, I don't even notice it so maybe it's less than I realize. Due to some surgery I've had I haven't used the table saw but once in the last few months and as I type this I don't recall ever having to make compensation for any backlash. There's bound to be some but it must not be significant.

 

Ok, thanks for the reply. Yea, it’s not much on my saw but I was wondering if the play in the shaft and fact that the saw arbor and blade moves when you pull on it, whether this would cause issues with the cut.

 

play in the shaft and fact that the saw arbor and blade moves when you pull on it

Mine doesn't do that at all, no movement. Have you checked to make sure everything is tight, adjusted properly? The arbor and blade moving when pulled doesn't sound very safe.

 

Yes, everything is tight, I’m assuming maybe the gear segment needs to be adjusted so there is no play between the raising worm gear and the gear segment bolted to the saw arm?

 

@richc64 I never did come up with a precise or incremental way of adjusting the gear segment to reduce the slop. If I recall correctly, it just came down to trial and error loosening the the gear segment, nudging it, and re-tightening. After probably a dozen tries, I got it to where the backlash and wiggle when lifting on the arbor is gone and nothing binds up when cranking the arbor up and down through it's whole range. The one thing I remember clearly is that it was a very frustrating process and I eventually had to set my perfectionism aside and settle with "good enough".

 

Where do you even get parts for these saws?

 

Powermatic, I guess. That's where I ordered mine from years ago when I did my restoration, I just assume they still have inventory but I could be wrong.