I’ve stumped Bob Van Dyke with this problem and he suggested I contact this forum. I have a Powermatic 66 Tilting Arbor Cabinet saw I purchased new in 1987. Recently I’ve noticed a problem that is driving me crazy. I’ll try to describe it the best I can.
Whenever I tilt the blade and then bring it back to vertical, the blade is no longer aligned in the horizontal direction but is still parallel to the miter gauge slot. I see this because I have a zero clearance table insert that shows a 1/16″ – 1/8″ shift to the left after tilting. I loosen the arbor shaft set screw and tap the arbor to the right to realign the blade, then tighten the set screw. Once this is done, I checked to see if I could move the blade left, which I cannot. However, the tilting then throws off the alignment again.
Please help!
Replies
It would seem that you have diagnosed the problem, that the arbor and bearing assembly is coming loose and shifting over when the carriage is tilted. Why the set screw won't hold the bearing assembly is a little less clear, but it isn't a prize piece of engineering to use one small set screw to hold that large of an assembly in place.
I would pull the set screw out and see what shape the tip of the set screw is in and clean it off and tighten the screw up with some medium grade Loctite on the threads.
If the problem continues, you will probably have to take the table off the saw and pull the arbor assembly out to see what shape the spacer between the bearings is in. The set screw bears on the spacer, if the spacer is badly chewed up the screw may not be able to get a good purchase on it. Once the table is off, actually removing the arbor assembly is relatively easy. The procedure is described in the saw's manual.
John White
Thanks John,
I did take out the set screw and put on some loctite. The screw looked fine, but I'll check it again. After I did this I tried to lever the arbor with a 2 ft piece of hardwood and it didn't budge, but maybe I wasn't pushing hard enough. I don't look forward to taking off the top, since I assume I have to remove my Biesemeyer fence first. But that is better than the aggravation of a constantly shifting arbor.
Taking the top off is easy, it is removing all the things that are attached to the top that takes so much time. In theory, and with some help, you could take the top, wings, and fence off as a unit by just lifting it an inch and moving the full assembly onto a nearby set of saw horses.I have to admit that it is a bit mysterious why the arbor assembly should be loosening up, I'd love to know what you discover.John White
I'll let you know what I find - hopefully I can get to that this week. Thanks for the prompt reply and help.
Hi John,
I took my 66 apart, fence rails and all and removed the top. Not bad once you've done it. I removed the pulleys and took out the arbor. The set screw looked fine, but the spacer had some scores in it from the set screw. I rotated the spacer and reassembled the whole thing. I tried to move the arbor using a piece of wood as a lever on the arbor and it held fast. I also tested it with some tilt and it held. Thinking I solved the problem, I went back to work. Today I had to make a 45 degree cut so I tilted the arbor to that position and immediately noted a shift from the insert position. Looks like I'm back to square 1. Any suggestions?
This forum post is now archived. Commenting has been disabled