A different cabinet saw adjustment

[Jamie Buxton]

Most cabinet saw owners know about aligning the miter slots to the blade. However, there is an additional tweak may help your saw. It certainly has helped mine. After you’ve aligned the top while the blade is vertical, try setting the blade to a 45º bevel. Using a tightly-fitting miter gauge, cross cut something and look carefully at the cut. You’d like to see that both the leading and trailing edges of the saw leave marks on the cut. If you don’t, you may benefit from further tuning. In the photo below, there is an example of a big need for further tuning. The blade is beveled over at 45º on this tilt-right saw, and it produced the cut on the piece of plywood. I ran the plywood only about halfway past the trailing edge of the blade before I stopped and took this photo. You can see the burning. It is caused by the trailing edge of the blade rubbing on the cut which had been made by the leading edge of the blade. That is, the trailing edge of the blade is to the right of the leading edge. It turns out that this can be cured by inserting shims under the front edge of the table, between the table and the cabinet. In this case, the shims are .030” thick – which is three standard business cards. With the shims, the saw now tracks correctly, even when knocked over 45º.

[Norman Hitt]

Excellent observation, Jamie. Although I discovered this many years ago, it's something that rarely, if ever, gets mentioned in saw tune up checks and procedures. This is a great post for those who are unaware.

[Jim Becker]

Theoretically, this adjustment "should" have been performed at the factory (that's why I and others often caution folks about removing the top from a cabinet saw so that the shims are not lost/mixed up), but knowing about it is pretty important if you happen to cut bevels. Thanks for detailing it, Jamie!

[Jim Barrett]

Interesting Jamie, thanks for the info. Not sure if I understand how shimming the top changes the 45 degree set up :confused: I would think if you are running true with the miter slot at 0 you would be OK at 45? Guess not, eh..

Jim

[Ted Shrader]

Interesting Jamie, thanks for the info. Not sure if I understand how shimming the top changes the 45 degree set up :confused: I would think if you are running true with the miter slot at 0 you would be OK at 45? Guess not, eh..

JimJim -

The blade tilt mechanism (trunnion) pivots about an axis running front to back on the saw. The table top must be parallel to this axis. If it is not, the wood is running uphill (or downhill) in relation to the blade. Imagine the blade tilted to 45° and then pushing a piece of wood through the blade from down low to up high. Same thing.

With the blade tilted, a chord drawn across the blade at table height must be perpendicular to the blade's axis of rotation about the arbor and parallel with its axis of rotation about the trunnion.

Regards,
Ted

[Rob Blaustein]

Jim,
There is a brief discussion of this issue in Jack Loganbill's excellent review of the Grizzly 1023 saw--at the very end (http://www.thewoodshop.20m.com/g1023s.htm). His site contains a wealth of information--very thoughtful reviews of tools with equally thoughtful discussions of technique.
-Rob

[Jamie Buxton]

Jim Becker --
Yeah, this is an adjustment I've never seen discussed. However, I suspect that lots of saws need it. Mine needed only a 30 mil shim to fix it, and I can't imagine that all saws are manufactured to that precision.

Jim Barrett --
Ted describes the geometry correctly. The thing to remember is that if the rear of the blade is to the right of the front of the blade, the front of the table needs to be shimmed up. If the rear of the blade is to the left, the rear of the table gets the shims.

Rob --
Interesting. The Grizzly folks shim the trunnions, while I shimmed the table. I don't know how the Griz is built, but even getting to the trunnions on a Unisaw is a big effort. I think you start by completely removing the table. Shimming and testing and shimming and testing would be a PITA. In contast, the Unisaw's connection from the table to the cabinet is quite accessable.

[Dave Harker]

FYI, my grizzly G1023SL owners manual does describe how to test for this 45 degree alignment issue, and how to correct it (shims under table).

This manual can be downloaded from grizzly's website.

[Jim Barrett]

Hi Jamie,

Ok I understand, so where do you place the shims? I measured my new General at 45 degrees and it "heels" to the left about .010. Also noticed no shim/washer under the left rear bolt (rear would be the furthest away from the controls) the three other bolts did have a shim/washer. I did a test cut and it looks fine. Don't think I am going to mess with it. BTW when I checked the blade to miter slot it was .002. Not going to mess with that either :)

Jim

[Jamie Buxton]

Hi Jamie,

Ok I understand, so where do you place the shims? I measured my new General at 45 degrees and it "heels" to the left about .010. Also noticed no shim/washer under the left rear bolt (rear would be the furthest away from the controls) the three other bolts did have a shim/washer. I did a test cut and it looks fine. Don't think I am going to mess with it. BTW when I checked the blade to miter slot it was .002. Not going to mess with that either :)

Jim

Jim ---
The .002 measurement is one I wouldn't mess with either. However I might tweak the .010 one. The key issue for me is not what the micrometer says, but what the cut says. I finally got irked enough to track down the problem in my saw because I kept finding that beveled crosscuts weren't coming out right. If I didn't feed the wood completely through the rear of the blade, the cut seemed curved. That was because the front of the blade cut at one place, and the rear of the blade was cutting someplace else. Also, on woods like cherry there would always be burning.

As to where you place the shims, it may depend on your make of saw. On my Unisaw, the shims go between the table and the cabinet. On the Griz 1023, we have one report in this thread (Dave) that the shims are like the Unisaw, but we have another (Rob) that the shims somehow adjust the trunnions in the cabinet.

[Rob Blaustein]

As to where you place the shims, it may depend on your make of saw. On my Unisaw, the shims go between the table and the cabinet. On the Griz 1023, we have one report in this thread (Dave) that the shims are like the Unisaw, but we have another (Rob) that the shims somehow adjust the trunnions in the cabinet.
Hmm, I see there may be a bit of a discrepancy with respect to the 45 deg adjustment on the Grizzly. On Loganbill's site he quotes the Grizzly rep who suggests shimming "between the trunnions and cabinet base", but as Dave points out, the 1023 manual advises shims under the table. I imagine both would serve to tilt the table, so I'm not sure that it matters, but haven't done this so should reserve comment. If there are Grizz owners familiar with this, you might want to chime in.

[Anthony Diodati]

Old thread I know, but if a table needs shims say in the front, do you have to loosen all 4 bolts?
Looks like you would have to start all over if you had to loosen all 4.

[Metod Alif]

The axis of blade's tilting must be parallel to the miter slots. Only top view parallel (blade parallel to the miter slots) is not a guarantee This calls for horizontal (much written about) and vertical (shims) adjustments/tuning. Think of two lines. They might appear parallel in one view but crossing in another.
Best wishes,
Metod