Dear John,
I have an old (1969) PM66. I moved it with me to Michigan and have just reassembled it. (Before I moved here I replaced the arbor, sheaves and belts, cleaned and reassembled it.) Today I finally got the miter slots parallel to the arbor flange (much more fussy than usual). When I raised the blade I noticed there appeared to be a slight drift to the right as it reached its highest point (I was watching the blade rise in relation to the aftermarket splitter slot and saw the movement). I lowered the blade, placed my homemade indicator on the blade and raised the blade again. Sure enough, it pushed it to the right. I checked for square with the table top and as it goes higher the top of the blade tilts slightly, but noticeably, out of square to the left. Is this usual? There appears to be no tilt or drift until the blade gets very near the top of its rise. My first inclination was that the worm gear and the raising arm were not seated correctly and was somehow skewing the arm at the top. There is some play in the blade arm (up and down). and the set screw is tight. If this is the case, how would I go about re-seating the worm gear with the arm? Is there something else I need to look at? Thanks for your time.
Scott
Edited 2/6/2007 1:37 pm ET by scooteruk
Replies
The blade shouldn't be skewing to the side as it approaches full height, so there is something wrong.
The worm gear only pushes upward on the arm assembly, the actual alignment is controlled by the pivot bolt or pin so I would look for something loose or not properly adjusted there first. The other thing to look for is something fouling the arbor support arm as it comes up, forcing it to the side.
I have a PM 66 in another shop, if you can't find the source of your problem, I'll take a look at that saw to see if I can give you some more specific things to look for.
John White
Thanks John!
You are right again! I took the top off and raised the blade. As it got near the top I saw the arm bind a bit. The motor was rubbing against my shop-made motor cover before topping out. I took off the cover and, voila!-no drift.
A couple more questions if you have the time. First, the blade arm bottoms out on the trunnion and the elevator crank/shaft goes loose and sloppy. When I check newer saws that is not the case. I tried adjusting the worm set to see if it would help but it didn't (I may be doing this incorrectly-PM's manual is not real clear on this issue). I thought it might be related to how the motor mount is bolted to the blade arm unit since the top edges did not perfectly align. I tried to make some adjustments. This did not change anything. I don't like the play in the elevator, but since it locks down fine, it probably isn't a functional problem other than the occasional banging of the arm against the trunnion. Any suggestions?
Next, this whole thing started because I wanted to get some dust control in this old saw. Hence, I built the cover (with the wrong dimensions) and tried some after-market items that didn't quite pan out. Other than building an internal sheetmetal slide with a dust port, do you know of anything? This machine really kicks up the dust.
Thanks again for taking the time to help out.
Scott
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