I think I’m going insane.
After doing routine maintenance on my TS this past weekend, I made a test cut to verify my “90 degree” setting was really square to the table. It wasn’t — it looked to be off by a degree or two. I’d checked by cutting through a 1 x 2 (across the long dimension), then flipping one of the pieces over to verify it was square (as I said, it wasn’t). I also noted that my tilt setting was not against the 90-deg stop, which surprised me.
Hmm, I said, left the tilt setting where it was and whipped out my 4″ engineer’s square to check. The blade was perfectly square to the table. I made sure I wasn’t against a tooth; I made sure the wide end of e-square was flat on the table; I made sure I could see no light between the e-square narrow blade and my saw blade. It was dead flat perfect.
I made another test cut. It was clearly NOT square. I check the squareness of the board itself. It was square. I grabbed my 6″ engineer’s square and checked everything again. Table-to-blade: square. Test workpiece: square. Test cut: NOT square.
Finally, I cranked the tilt to the stop and made another test cut. It was perfectly square. I checked with the e-square again: there was a noticeable gap, indicating the blade was off-square.
What the heck could be going on?
-M.
Replies
Mark, does the blade have a taper? Also check the arbor flange and blade for dust. If I understand you correctly, the cut comes out square when trunnion is against the 90 degree stop, but the square shows the blade is not square to the table. Try another blade, or a flat piece of metal with a 5/8" bore. I have used 1/4"x 2" aluminum flat stock for checking perpendicular.
Mike
Excellent suggestion. I've actually got an alignment plate I can use to check this; I was just so frazzled by what I was seeing that I forgot about it.
-M.
The real test is the cutting. But before you adjust for the cut, be sure that the wood is not slipping on the face of the miter gauge. The miter gauge face should have 100 grit sandpaper affixed to it with double faced tape. That prevents slipping.
After I tune up a saw, I always cut a sample and do my final adjustments from the cut, not my "alignment" tools.
OK, I sheepishly have to admit I found the problem. My throat plate was a few hundredths of an inch *above* the table, and the wide blade on my engineer's square was straddling the plate and the table, but being slightly pushed up by the throat plate. Duh. I didn't figure this out until I put my alignment plate on and was measuring perfect "squareness" on both sides of the alignment plate -- with the throat plate, of course, removed. I put a blade back on, still measured square, then put the throat plate back on and suddenly realized what was happening.
To say I felt foolish is a gross understatement.
Thanks to everybody with suggestions!
-M.
Mark, don't feel foolish, I suggested the alignment plate, check blade etc and never thought about throat plate height. Glad you found it, your post will help others.
Mike
Sheesh! I almost suggested checking that, because I've had the same problem with one of my saw's plates, but bit my tongue and stayed silent! Sorry. At least it was an easy fix.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
I had the same problem using an machinests' square on top of the insert to check the blade when it was fully raised. I read somewhere to remove the insert and check the blade in the down position, ie, with the square's stock resting on the table and the square's blade down and against the lowered blade. This allows sighting along the almost full diameter of the blade, and it is easy to see if it is out of alignment. Never trust the insert to be flush with the table. I use a try-square that has been checked for squareness. Not all squares are square!
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