Adjusting the miter fence

[LarryG]

How about using the 3-4-5 rule? I've tested my square this way more than once and it seems to work OK. Call me paranoid but I don't trust plywood edges, or any other lumber edges to be "straight".

The 3-4-5 rule will work as long as you're able to read the rule accurately. With advancing years I'm inclined to deal with counting all those little hash marks as little as I can and find some other way.

I'm wary of "factory" edges on plywood, too. They're often nowhere near as straight as one would expect them to be.

[hilux]

Make sure the table top is level both ways

[LCHIEN]

I believe that the problem was that both the SMT base was out of square AND the miter fence was not exactly square to the blade. First, I made note of which direction I had adjusted the miter base and when that adjustment improved the cut I continued adjusting in that direction. I also discontinued the use of the quickstop, which I think needs readjusting, and set the miter guage much more carefully.

Thanks to all of you who contributed their time and ideas toward helping me.

I greatly appreciate your assistance, as well as the efforts of all those who share their expertise in these forums.

Now that you are all done, I might make these points:

1) the SMT not tracking parallel to the blade will Not result in miter cuts that are not square. IT may lead to burning, too large a kerf, rough cuts, blade marks etc. but the sole determining factor in whether its square or not is the angle of the miter fence to the blade, which as pointed out is easy to check with a good square or draftsman's triangle.

2) If you're adjusting everything, the quick stop needs to be set, too.
It works fine after being set correctly.

3) miter angle errors can be cause by several things (might want to check the BT3 FAQ) from largest to smallest:
a) pivot in the wrong place
b)failure to use te orange thingy as an indicator
3) failure to hold the wood tightly to the miter fence
4) use of the Ryobi miter clamp accessory which has a compound action of pushing down on the wood and against the fence which can actually move the miter fence if you tighten the clamp more than you tighten the miter clamp.
5) parallelax from looking at the indicator and scale at an angle other than straight above.

If you have or don't know if you have any of these problems then I'd advise checking your set miter angle with a reliable, known good square before and after the cut, and observe the wood in relation to the miter fence itself, until you have the teqchnique down pat, and have confidence in your skills and the machine.

[buddyroo]

Thank you for the tips. I did think that the orange thingy was a little strange, but it seems to work fine.