Replies

1. 
   lwilliams | Jan 06, 2009 05:17am | #1

   Loosen the 3 bolts and move the table. About 10 minutes if you have a dial indicator set up to true the table.

1. 
   mapleman | Jan 06, 2009 07:41am | #4

    

   Loosen the 3 bolts and move the table. About 10 minutes if you have a dial indicator set up to true the table.

   While I respect Larry, I couldn't disagree more. It is highly unlikely that the table moved over that much on it's own. Downright impossible.

   Likley what has happened is this:

   The blade arbor has 2 bearings, you cannot see them, they are "trapped" in a cast iron housing - when looking down through the throat plate from the front of the saw - blade is on the right and arbor pulley is on the left of this housing.

   On the top of this housing is an allen grub (lock) screw. This screw locks the arbor in it's position left/right. More than likely what has happened is this screw has come loose and the whole arbor has shifted over. The bearings in this housing are a interference fit but not extremely tight. Loosen the lock screw a little more and then tap the arbor over either left or right. When it's in the position you want it, I would remove and replace the lock screw adding some BLUE loktite to prevent this from happening again. I just replaced my arbor shaft on a PM 66 a few months back so this is still fresh on my mind.

   Good luck and if you need any other help just drop a line.

    

   Lee

    

   Edit: Post should have been addressed to OP, not lwilliams

    

    

    

   Edited 1/5/2009 11:42 pm by mapleman

1. 
   lwilliams | Jan 07, 2009 03:25am | #6

   Hi Lee,I think it's nothing more than an assumption the table moved accidentally. The top could have been removed for a number of reasons, it could have been poorly adjusted at some point or simply adjusted to fit a shop-made table insert. We have two 66 saws, one of which I've worked with for more than 25 years. I'll be real curious to hear what the OP finds when he works with the saw. I hope he doesn't break down the arbor unnecessarily.

1. 
   mapleman | Jan 07, 2009 03:58am | #7

   Hi Larry,

   I guess we'll see. I just haven not run into a situation where the table has moved "accidentally". Someone having moved the table intentionally would not be smart but in a classroom situation could not be ruled out.

   As far as "breaking down" the arbor, it's really not a big deal and the process is outlined in the saw's owner's manual. I don't recommend removing the arbor but  sliding it left to right , if that is indeed the reason it is out of position. It would seem that would have been more likely the reason for the movement.

   Lee

2. 
   boilerbay | Jan 07, 2009 06:13pm | #8

   Lee, I would have to agree with you in that there are only so many ways on that particular saw that the blade could remain parallel.
   Arbor or throat plate only.
   Doesn't matter if top was removed or hit, the three mounting bolts are positioned in such a manner as to only allow axis turning. Unless all three bolt holes have been after market elongated parallel to the rails, the top can''t be adjusted left or right.I think....Boiler

1. 
   wood1000 | Jan 07, 2009 08:45pm | #9

   The abor was loose which made the movment easy.  I will go back and check in on it in the spring.  Do I need to recheck the set up?  Thanks guys! 

   Edited 1/7/2009 12:45 pm ET by Wood1000

1. 
   mapleman | Jan 08, 2009 04:58am | #11

   Wood,

   Here is what I would do:

   Check the throat plate that is/was on the saw. If there was a zero clearance plate with a small slot (in other words, not wallowed out)  for the blade, then I would slide the arbor over until the blade passes back through the old slot.

   If the stock Powermatic throat plate is installed, then forget it because that blade slot is about 1/2" wide (from my recollection).

   Blade position from the left side of the throat plate opening on my saw is: real close to exactly 1". In other words if you measure from the left side of the throat plate opening to the closest edge of a blade tooth it's about 31/32nds.

   Keep in mind my saw is a 2001 model - I can't be certain if your saw will use the same measurement. However, remember this: The position is not exactly critical, AS LONG AS THE BLADE DOES NOT CONTACT ANY PART OF THE SAW WHILE SPINNING (MORE ON THAT BELOW)

   If your position is off from where it was before you moved it and you have jigs that are sized for that blade position (from the miter slot) then those jigs will no longer be accurate.

   Please make sure after you move the blade into it's new position, that you: run the blade up and down all the way to make sure the blade is not contacting any part of the trunnion or saw frame that it's not supposed to. Then tilt the blade all the way to 45 degrees. Then, with the blade tilted to 45 degrees, raise and lower the blade all the way a few times. You want to make sure that you don't reinstall the arbor in a position that would cause the blade to strike cast iron if a student raises or lowers the blade while it is tilted. Do all of the above with the power off, of course.

   Also, when you are satisfied that you have the arbor in a good safe postion, back out that lock screw and put a dab of blue Loktite on the threads. That should prevent the problem from happening again. Be sure not to use red loktite, you may never get that lock screw out again!

    

   Best of luck,

   Lee

2. 
   boilerbay | Jan 08, 2009 05:57pm | #12

   Wood,As long as your going to dive in with, as Lee says, "with the hood up" it would be a great time to super tune the saw. New belts, pulley damage, power cords, clean switch and check brushes, worms and slides, reset the 45 and 90 stop points. A good time to remove any original factory Powermatic green/yellow paint from any where near the mounting bolts and the bolts themselves as this paint prevents the top from being really tightened down. Acts like grease. Major cause of blade going out of miter parallel. Also remove grease on underside of table top. Powermatic painted the cabinets and but usually coated tops with grease when shipping. Owners remove shipping grease from top but don't think about the screw areas on bottom.
   Factory paint on the worms also makes them harder to drive (even with DuPont lube) then need be, so a good wire brushing and new Teflon helps there.
   Be careful of how tight you bring down the bolts... it is cast iron so no torque wrenches :)Do all that and your good to go for another billion board feet... give or take some inches...Boiler

2. 
   mapleman | Jan 08, 2009 04:44am | #10

   boiler,

   Good point. It's been a long time since I had the "hood up".

   Lee

2. 
   RDNZL | Jan 06, 2009 06:06am | #2

   It would be unusual for something to have moved that much - and from your limited description, in a parallel fashion....

   Further, even if something DID move, it would have taken a hell of a whack to move the table, or (I'm assuming here) major mechanical failure for the arbor to have moved.

   Could it be something more simple - like an aftermarket or shopmade or bastard throat plate that has also had a dado blade run up into it?

1. 
   wood1000 | Jan 06, 2009 06:12am | #3

   You are right it is in a parallel fashion that the blade has move.

3. 
   Sawyer | Jan 06, 2009 07:50am | #5

   Could it be as simple as a blade dampener put on the wrong side of the blade?  (Or possibly an extra flange?)  I agree with those who doubt the table just "moved."  I am surprised the shop teacher couldn't figure it out though...

4. 
   BrianDerr | Jan 09, 2009 10:36am | #13

   Add, remove or reposition a spacer/stiffenner on the arbor to change the position of the blade? Maybe one was lost or installed wrong at the last blade change.

   Brian

1. 
   wood1000 | Jan 09, 2009 11:57pm | #14

   No there has always been one stiffener on the right side of the blade.