Can the Shapeoko cut 45 degree mitre joints?

I have some 1/2" baltic birch and need to make some boxes. Can I put a 45 degree bit and have it cut the mitre joints? Has anyone tried this and had success? What bit did you use?



Look for videos by John Clark on utube. Pretty neat stuff.


Yes, one can do this with a 90 degree endmill — I’ve actually got some further ideas on this which I’m trying to find a suitable CAD/CAM tool to work them out using.

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I’ll check them out. Thanks so much for the lead.

Let me know how I can help. I’ll do some test but right now feel I just need to find the right bit that can do that depth (doing the whole a^2 x b^2 = c^2 math it would need at least a cutting length of ~0.71).

Is there a 90 degree end mill with a 1/8" collet that would work for this? Also I’m wondering as it gets deeper it would be cutting a lot of surface area at once…so I would need to do this super slow?


I use a standard router v bit capable of cutting 3/4 " deep ( I think it has a 1" cutting length) to do miters on my router table. I suspect you could do the same on S3 although I have not tried it.


Not saying in couldn’t be done on an SO3, but is that a bigger router with a 1/2" collet?

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Yeah, that’s what I want to try. Will keep you posted once I do a few tests. And yes, I do need to find something that’s 1/8" collet…unless there is a way to get a 1/4" collet on the S3?


What router/spindle are you using?

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DEWALT DWP611, though wouldn’t hesitate replacing it if I could accomplish this goal with a bigger collet.

Comes with a 1/4" collet.


The Makita (or Carbide Compact Router) can accept a 3/8" collet:

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Awesome to know. I may just have to upgrade.

Any opinions on which router is better (makita vs. Carbide)?


Yep, do a search and check how many threads are about Makita problems and Carbide Router Problems

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Cool, will do. Thanks for the response.

Maybe this isn’t important to you, but Vectric software Vcarve will make the appropriate allowances for that deep-vee joint when you specify the correct thickness of the material. You don’t need a bit with 0.75" cutting depth.

I haven’t tried it with my machine, yet. (They say it uses magic. :smiley: )

EDIT: So, my mind wouldn’t cooperate, so I started to search on the Vectric forum to no avail. So, I asked (something I never do with a map in front of me! :smiley: !

In the program Vcarve, you create a rectangle with a width of twice the material thickness, and a length about 2" longer than the width of your cut. Then you simply create a V-carve toolpath. The toolpath is created with enough passes to make the miter. Using a separate clearing tool is highly recommended.

Thanks to “highpockets” on the Vectric forum for helping!


I have cut 45deg with a 1/2in 90 deg 301 Vbit . You use a 1/2in deep profile cut and you cut on the line. It makes perfect mitered joints. If you want to go bigger a 3/4in 90 deg with 1/4in shank is available from Amana but it is a bit pricey.


I have made a lot of boxes over the years. 45 degree miters on plywood are a disaster waiting to happen. If you want a 45 degree miter you need to add splines. The plywood is very porous and makes a poor gluing surface. If I were to make 1/2" boxes I would make them with Kreg pocket screws. If the boxes are utilitary for the shop it does not matter about the pocket holes and they can be plugged. If you have only one tool and it is a hammer then every thing looks like a nail. So the Shapeoko is a great machine it is not necessarily best for every project. However you make 1/2" plywood boxes add splines to make sure they hold together with heavy loads.


I definitely plan to use splines to keep things together. We’re using baltic birch which is a higher quality of plywood…but yes not the same as gluing up real wood. We have done some tests with a 45 degree bit on a router table, and they came out quite nice.

Many thanks for the responses.

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I can’t 100% picture how this works. I wonder if there is a youtube video about this.

But alas I do not have vcarve so will probably just put down a line in carbide create, put the 45 degree bit on, and have it slowly go back and forth getting deeper along the line until the Mitre is complete. I’ll hopefully have time this weekend and will post the results.