PM66 Blade Alignment Issue

[Ryan Ess]

Hello, I've been having a problem with my table saw. As I raise the blade it shifts to the left; approximately .070" across it's travel. Obviously this is a problem when using sleds, zero clearance inserts, splitters, or fences with scales. The blade doesn't have any appreciable change in tilt angle or alignment to the miter slot as the blade height is changed. I recently tore everything apart, meticulously cleaned, and lubricated it all. The saw really needed it anyway, but I had hoped that it would resolve the issue. Unfortunately it did not. Any thoughts on what might be causing the problem? The only thing I can think of is a misalignment between the worm gears that adjust blade height. Any help would be greatly appreciated.

[glenn bradley]

Is the blade tilting out of plane or shifting front to back?

[Ryan Ess]

It isn't tilting at all. By shifting front to back do you mean moving out of parallel to the miter slot?

[andrew whicker]

So if you ripped a board with the blade at 1" height and then ripped another board at 2" height without moving the fence you would get different board widths?

(sentence above is probably a run-on sentence. sorry.)

[Martin Wasner]

Likely a similar problem (http://www.sawmillcreek.org/showthread.php?164267-What-a-dumb-design&highlight=)?

[Ryan Ess]

So if you ripped a board with the blade at 1" height and then ripped another board at 2" height without moving the fence you would get different board widths?

(sentence above is probably a run-on sentence. sorry.)

Yes that is correct.

[Bob Vaughan]

Sounds like a problem around with the pivot pin (3711005) being a little loose in the main box casting. On the left side there should be a snap ring (6670092) and a steel circular washer (6811327). Check to see if the snap ring is in its groove. Second option to check is the tightness of the pin nut (6578003). It could also be that the bearing arm (3025042) is loose on the pivot pin, but this would be unusual.

[Ryan Ess]

Likely a similar problem (http://www.sawmillcreek.org/showthread.php?164267-What-a-dumb-design&highlight=)?

The set screw that holds the assembly in position is very tight and there's no play. So I feel comfortable saying that isn't the problem. Plus the lateral shift is very steady and repeatable. If the assembly was sliding around on the pivot shaft I think the blade shift would be erratic.

[Ryan Ess]

Sounds like a problem around with the pivot pin (3711005) being a little loose in the main box casting. On the left side there should be a snap ring (6670092) and a steel circular washer (6811327). Check to see if the snap ring is in its groove. Second option to check is the tightness of the pin nut (6578003). It could also be that the bearing arm (3025042) is loose on the pivot pin, but this would be unusual.

I confirmed the snap rings are seated in their slot on the pivot shaft. The pivot nut is snug too.

[Bob Vaughan]

Remove the blade throat plate and look down in there while raising and lowering with no blade installed. Maybe tape a piece of paper here and there to see if things move into or away from the edge of the paper. .070 is a lot and totally wrong.

If the tilt stop bolt has drifted down, that will make the blade tilt slightly and thus raise and lower at a tilt.

[Ryan Ess]

Remove the blade throat plate and look down in there while raising and lowering with no blade installed. Maybe tape a piece of paper here and there to see if things move into or away from the edge of the paper. .070 is a lot and totally wrong.

If the tilt stop bolt has drifted down, that will make the blade tilt slightly and thus raise and lower at a tilt.

I haven't set the stops since refurbishing everything. So they're completely out of the way. I'm not experiencing any tilt issues. The blade is staying straight up and down, and parallel to the miter slots throughout the vertical travel. It's very odd the way it shifts to the left without any of the usual issues I see discussed. Most people have tilt or wobble issues.