Contract Saw Alignment Revisited

[ssmith1627]

Very weird. Tried replying to my earlier thread on this subject. I posted the message. But when I view the thread I don't see the message. Not sure what's going on. So I just started a new thread below. Sorry for any confusion.

Steve



Hopefully you guys don't mind me reviving this thread. Belated Merry Christmas to all !

I've had some time to do a little more testing with my saw's alignment. The PALS are on the way but in the mean time I'm still trying to come to grips with this runout issue.

I tried testing the blade runout with a jig and with a magnetic base for a dial indicator. I get the same results. I remove the ZCTP so it doesn't interfere. I also removed the belt from the motor -- should I or shouldn't I ? On that part I wasn't sure.

I rotate the blade with the jig in one place and I see runout of 0.006 to 0.008 inches. I tried with a 2nd blade, same result. I cleaned the arbor, the arbor flange and the washer and tried again but got the same basic results. It's repeatable.

I'm not testing for miter slot alignment at this point. Just runout. The jig stays in one place and I keep even pressure on it. I can even spin the blade so that it's moving freely without my accidentally applying any side pressure. I can find the extreme for one direction, set zero on the dial indicator and then spin the blade and you can see the range of motion on the indicator.

I used the extensions for the indicator arm and tilted the indicator to put the tip against the flat surface on the arbor flange, the area where the blade would rest. I barely see the needle move as I turn it through a revolution. MAYBE 1/4" of one thousandth of an inch if anything. That almost confuses me more. Obviously the testing with the blade is about 4" further out and any runout would be exaggerated but the two still don't seem to agree.

Any ideas ? What am I not understanding here ?

One other question -- sorry for the long note ! -- do you guys hear ANY sound when you turn the arbor shaft to spin it or spin the blade ? I hear random, not constant and not frequent, clicking like noises. I have nothing to compare this with so I don't know what's normal and what isn't.

As always, thanks for your time. It's appreciated.

Steve

[LCHIEN]

maybe I"m missing what your exact problem is.
I assume you're crosscutting like a 1 x 6, with your miter fence set to 90 and the board flat on the table.
1 Is the cut not at 90 degrees to the back (trailing edge) edge of the wood?
2 Is the cut concave or convex, along the cut direction (the 6" edge) ?
3 or is the cut concave or convex top to bottom (concave along the 1" edge)?

As i pointed out in the earlier thread if its 1, then only your miter fence can be out of whack. Blade wobble or runout can't really affect that altho it will widen the kerf. In extreme cases which I doubt you have, then the cut would start to be concave top to bottom.

A wobble dado blade is an exaggerated case of blade runout, and they cut straight.
Either I don't understand your problem or you're barking up the wrong tree totally.