Shopsmith Forums

I cut the 22.5 degree miters on my Shopsmith using the miter gauge. I just cut scrap wood until I could lay 4 of them together and get a perfect 90 degree angle that fits my square. With that setting, the angles fit perfectly at the bottom corners.

I am confused at the concerns about making the angles its not that much work for the sanding disc ?

Hobbyman2 wrote: Mon Dec 13, 2021 12:15 am I am confused at the concerns about making the angles its not that much work for the sanding disc ?

That's the approach I would have taken too, with a rough cut on the band saw to start. With a jig for more angle range than the miter gauge has, it won't get to 67.5 degrees. But it looked to me like Bill V (wa2crk) got good results on a Mark in the thread JPG referenced using vertically mounted stock and table tilt: viewtopic.php?p=84836#p84836 Which is similar to what the OP is planning, I think, for the 67.5 degree miter cuts. Bill could weigh in, there is no close-up of the result and we are usually our own worst critics. It looked fine to me though.

- David

Hobbyman2 wrote: Mon Dec 13, 2021 12:15 am I am confused at the concerns about making the angles its not that much work for the sanding disc ?

I ran some numbers to illustrate the angular accuracy requirements.

• Given the 5/8" thick stock, the hypotenuse of the 22.5 degree bevel is 1.63". So that's the length of the miter-joint seam.

• If the miter angles are off by a mere 0.1 degrees over the 1.63" seam length, that causes a gap of about 0.003" per workpiece. So the total gap is double that, at about 0.006". Depending on which direction the angle is off, that gap could be either at the inside or the outside edge of the miter joint.

• These calculations assume that the lengths of the workpieces are perfect. But in actuality, any error in the length of any of the three workpieces will also cause miter gaps.

0.006" doesn't sound like a lot. But IMO, the joints already wouldn't look terribly tight with that much gap.

Now how are we going to set the Shopsmith table tilt to an accuracy of 0.1 degrees?

• There's no micro-adjuster.

• A typical angle indicator (e.g. Wixey) has a resolution of 0.1 degrees, a specified accuracy of +/- 0.2 degreees, and a specified repeatability of +/- 0.1 degrees. Plus we have to calibrate the angle indicator relative to the saw blade, which is a two-measurement procedure that doubles the potential error in the relative-angle measurement.

• Perhaps we could use the auxiliary table as a tilt stop. Then we could measure actual test-cut angles, and shim the stop point as required to correct the tilt angle.

It looks deceptively simple, but IMO this job calls for a special-purpose jig, a more accurate machine, or ideally both.

a jig would be a great idea , IMO I would still use the sanding disc , clamp the piece on the table in the correct angle in the jig and advance the disc into the work piece using the quill ?

Hobbyman2 wrote: Mon Dec 13, 2021 11:12 am a jig would be a great idea , IMO I would still use the sanding disc , clamp the piece on the table in the correct angle in the jig and advance the disc into the work piece using the quill ?

You might be on to something there, Hobbyman. The sanding disc will produce a nice flat smooth surface, for sure. Plus it's plenty big enough to sand 3-1/2" tall workpieces. The saw blade doesn't have enough height capacity for both a workpiece (on edge) and a jig base.

Using the quill to advance the disc let's you "sneak up" on the final workpiece length, using test-fitting to get them perfect. That wouldn't be very efficient for a production operation, but it would be dandy for a one-off project like this.

Finally, you can now finish the miter angles with the table set to zero degrees, which position is micro-adjustable. And it makes it easy to back up the main table with the Aux table, to increase the stiffness.

Getting resolution down to 22.5 degrees is still going to be hard with the standard Shopsmith miter gauge.

Using the sanding disc and something like the Incra Miter 5000 sled would make this project a relative snap with its 1/2 degree resolution and fence stop. Sadly, I don't think Incra makes the Shopsmith addition anymore. Jack Wilson (a member I haven't seen on the board in a long time) gifted me one at the same time he gifted me a couple of canoe paddles. The Miter 5000 is heavy and takes up a lot of space in my shop; but it is an amazingly accurate sled/miter gauge.

algale wrote: Mon Dec 13, 2021 12:40 pm Getting resolution down to 22.5 degrees is still going to be hard with the standard Shopsmith miter gauge.

Using the sanding disc and something like the Incra Miter 5000 sled would make this project a relative snap with its 1/2 degree resolution and fence stop. Sadly, I don't think Incra makes the Shopsmith addition anymore. Jack Wilson (a member I haven't seen on the board in a long time) gifted me one at the same time he gifted me a couple of canoe paddles. The Miter 5000 is heavy and takes up a lot of space in my shop; but it is an amazingly accurate sled/miter gauge.

The Miter Set jig should do it???

jsburger wrote: Mon Dec 13, 2021 1:25 pm

algale wrote: Mon Dec 13, 2021 12:40 pm Getting resolution down to 22.5 degrees is still going to be hard with the standard Shopsmith miter gauge.

Using the sanding disc and something like the Incra Miter 5000 sled would make this project a relative snap with its 1/2 degree resolution and fence stop. Sadly, I don't think Incra makes the Shopsmith addition anymore. Jack Wilson (a member I haven't seen on the board in a long time) gifted me one at the same time he gifted me a couple of canoe paddles. The Miter 5000 is heavy and takes up a lot of space in my shop; but it is an amazingly accurate sled/miter gauge.

The Miter Set jig should do it???

Oh, I didn't know the MiterSet had 1/2 degree resolution!

algale wrote: Mon Dec 13, 2021 1:29 pm

jsburger wrote: Mon Dec 13, 2021 1:25 pm

algale wrote: Mon Dec 13, 2021 12:40 pm Getting resolution down to 22.5 degrees is still going to be hard with the standard Shopsmith miter gauge.

Using the sanding disc and something like the Incra Miter 5000 sled would make this project a relative snap with its 1/2 degree resolution and fence stop. Sadly, I don't think Incra makes the Shopsmith addition anymore. Jack Wilson (a member I haven't seen on the board in a long time) gifted me one at the same time he gifted me a couple of canoe paddles. The Miter 5000 is heavy and takes up a lot of space in my shop; but it is an amazingly accurate sled/miter gauge.

The Miter Set jig should do it???

Oh, I didn't know the MiterSet had 1/2 degree resolution!

Yes it does.

https://www.youtube.com/watch?v=VFeR9JBfI7c&t=98s