Unisaw alignment

[Michael Arruda]

Hello all,

I'm trying to align my Unisaw. I used an Angle Perfect and a Groz engineer's square to align the blade to the miter slot. I crosscut a piece of wood and it still rubbed on the blade at the back of the sawblade as it was exiting the cut. I then measured run out. The arbor flange has .004 runout, and the blade plate just bellow the gullets has .010 runout.

Then blade is an old Forrest I got from a friend, and the Unisaw is from 1969.

Even though the angle perfect and square say the blade is square to the miter,when I put that same square on the piece of wood I cut, I can fit a .008 feeler gauge between it and the wood, so it's not cutting square.

Any ideas?

Thanks,
Michael

[Bruce King]

Sounds like some play in the miter track. You can use a center punch to deform the edges of the miter (not the table slot) to make it fit tight again. Or you can just adjust the miter fence.

[Greg Peterson]

Before you go dinging your miter slots, try a different blade. I use a Master Plate for aligning my saws. Makes the task much easier.

[Michael Arruda]

I cleaned the flange with alcohol and cleaned a small bit of pitch that I hadn't seen with a straight razor. I now get .003 on the flange face. I've tried 6 blades, 3 forrests, a ridge carbide, an irwin and a no name, and they all come up with a variance of .008 (Ridge Carbide)- .012 (Irwin).

I guess it's time to figure out an elaborate jig to grind the face of the flange... :-)

Thanks for the responses,
-Michael

[Kirk Poore]

I cleaned the flange with alcohol and cleaned a small bit of pitch that I hadn't seen with a straight razor. I now get .003 on the flange face. I've tried 6 blades, 3 forrests, a ridge carbide, an irwin and a no name, and they all come up with a variance of .008 (Ridge Carbide)- .012 (Irwin).

I guess it's time to figure out an elaborate jig to grind the face of the flange... :-)

Thanks for the responses,
-Michael

No need for an elaborate jig. Here's what I did on my Powermatic 65:

Tools: Dial indicator, fine file, black Sharpie.

Mounting the dial indicator back in the saw, I measured .006 runout on the flange. I then rotated the arbor by hand and marked the high spot. Taking the fine file, I filed for a while. I was down to 5 thousandth out. Marking the edges of the flat spot, I gradually expanded it. Finally after 45 minutes of filing, I was about .001 out on the arbor, and .007 out near the edge of the blade. It sounds like your blade is flatter than mine, so you should get better final results.

That's been good enough for me. Note that you may need to take off the top of the saw to get room to work, and you'll need to realign the flange with the miter slot afterwards.

Kirk

[Michael Arruda]

Thanks Kirk!

I used your method with a small file. Unfortunately, the dial indicator is a HF special, and doesn't hold it's reading- When I was measuring the blade, I zeroed on one spot. After coming full circle, that same spot measured -.001. I did it again and it measured -.002, and the third time was back to .000. Pretty frusterating.

From what I can see, averaging multiple readings, I got the flange face to a .0018 or so variance. At the blade plate, just below the gullets, I'm reading about .004 variance or so. I'm much more comfortable with this and will now realign everything and try it out. Wish me luck! I'm hoping this will give me a cleaner cut.

Thanks again,
Michael

[Michael Arruda]

Okay, kinda getting to my wits end now. I need to check out the miter slot- maybe it's wallowed a little. I crosscut a piece of wood, and it looked good. When I put my engineer's square up to it, I could fit a .001 feeler gauge in, 4 inches from the corner. That's doable.

I then put on another blade. All adjustments the same, made another cut. This time a .008 feeler gauge fit in the same spot!!! ARGH!!!!

-Michael

[Kirk Poore]

Okay, kinda getting to my wits end now. I need to check out the miter slot- maybe it's wallowed a little. I crosscut a piece of wood, and it looked good. When I put my engineer's square up to it, I could fit a .001 feeler gauge in, 4 inches from the corner. That's doable.

I then put on another blade. All adjustments the same, made another cut. This time a .008 feeler gauge fit in the same spot!!! ARGH!!!!

-Michael

The miter slot or miter gauge would be my first guess here. I don't think a slightly out of alignment flange or warped blade would give you that. They would give you a rougher cut instead.

Kirk