CNC Cut Zero Clearance Insert

Recommended Posts


I recently got access to a Shopbot through a Tech Shop opening close to Austin. The first project I thought to use it for is cutting a zero clearance insert for my table saw.

I have this table saw from Porter Cable. The insert that came with it is thin stamped metal. The lip that holds the insert isn't deep enough to use 1/4" plywood like I see a lot of people use for inserts. So I designed a cut model that makes most of the insert 1/2" but puts a ~0.15" lip around the outside where the supports are. It also provides areas for all the structure under the insert, a pocket where the blade comes through, and openings for the adjustment screws.

You can see my progression of prototypes in one of the photos. I went through 5 tries before getting one that works. I still need to tweak the last one a bit more. I am having trouble getting the curves at the ends just right. Turns out that they are elliptical rather than circular, but the last one works with a little bit of sanding. I am also seeing a slight bulge in the middle when I put it in the opening which makes me think it might be rubbing somewhere on the underside.

There is a zero clearance insert that is sold for this table saw. However, I have not been able to find any dado inserts. I bought a dado stack a few months ago and haven't gotten to use it yet. My real goal is to cut a series of dado inserts (1/4", 3/8", 1/2", etc...). Now that I have the digital file more-or-less working, I can cut a whatever size I want.

Share this post

Link to post
Share on other sites

Awesome! Have you got these worked out? If so I'll take 10!!! I was planning on making some myself but these look a lot better than anything I'm going to turn out!

Share this post

Link to post
Share on other sites

Thanks!  I never got them to fit perfectly, but I got them close enough.  After the Shopbot, the blanks still have to be sanded around the edges to fit properly.  Once they do, though, the work great.


I am happy to share the files if you want them.  I have a V-carve and a Shopbot file.

  • Like 1

Share this post

Link to post
Share on other sites

I'm jealous that you have a Tech Shop in your town. For those of you who haven't heard of it, membership gives you access to just about any tool you need to build virtually anything. CNC Metal working, woodworking, 3d printing, etching, textiles, electronics, etc. Many, MANY commercial products found its start as a prototype built in a Tech Shop by individuals who don't have access to the resources of a large company. Just awesome.

Great job on your insert design, now you have access to an unlimited supply at the push of a button!

Share this post

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Who's Online   1 Member, 0 Anonymous, 1 Guest (See full list)

  • Forum Statistics

    Total Topics
    Total Posts
  • Member Statistics

    Total Members
    Most Online
    Newest Member