Acute Angle Miter Saw Jig

I needed a 70º cut for my Dowel Guitar Rack, but my miter saw can’t cut an angle that steep! I made a one-time use jig for that project, but decided to make a jig that I could have around that would be able to cut ANY angle I would ever need.

Check out the video below to see how I put it all together!

The principle behind this jig is simple. All we need to do is create a new fence at a fixed angle. That angle is going to be our new ZERO on the miter saw and it is going to make up the missing angles that your saw can’t cut!

This jig is made up of:

A base that is about the size of your miter saw base.

Two Fences with 45º miters on end.

Two Triangle support blocks.

STEP 1

Attach one of the fences to the base making sure it is at a perfect 45º to the edge of the base.

The mitered corner of this fence piece should be in line with the back of the base.

STEP 2

Attach the back fence.

The mitered corner on this piece should be up against the first fence installed in STEP 1.

The back of it should be flush with the back edge of the base.

STEP 3

Attach the triangle support blocks.

These may or may not be necessary, but they are just to keep the fence straight and square.

Make sure they are in a position where they won’t interfere with your clamps when using it.

The Jig is basically done!

All you have to do is clamp the back fence to the fence on your saw.

Align the edge of the jig with the edge of your blade and clamp it in place.

Using the depth stop on your miter saw, make score lines every 5 degrees.

Then label each score mark with the appropriate degree.

Since the fence was installed at 45º on the jig, when the saw is set to ZERO, that would actually make a 45º cut.

So if you move the saw to 5º that would actually make a 50º cut!

10º would be 55º

15º would be 60º

20º would be 65º

25º would be 70º

30º would be 75º

35º would be 80º

If you want to do the math here all you have to do is take your desired angle and subtract it by 45º because that is the new fence angle. This works for odd numbers too… let’s say you need a 77º angle.

77 - 45 = 32

So with this setup, if you need a 77º angle you would set the saw to 32º

Now there are multiple ways to clamps your workpiece.

You can clamp around the backside of the fence, over the top, or clamp to the base.

But clamping is definitely advised.

With this set up you can cut taller pieces.

And smaller skinny pieces.

This is because I made the fence the same height as the opening in my clamps.

That’s all there is to it!

Super simple and easy!

Look how clean that 70º cut is! Awesome.