Zero Clearance Insert (ZCI)


Used the plug-in to go to my SO and create this zci for my shopsmith 520. If the drawing was right then the part will be right, now was my drawing correct???

This insert has the cut out for the upper guard which is what I’m hoping will fit as I didn’t have an insert to measure so I ask for help and got answers over at the shopsmith forums. The real shopsmith part has pretty square edges in the insert but the best I could do is make a pass with an 1/8" bit which I hope will be good enough. If not then a little hand filing will fix that.



I MIGHT have that same insert on my Shopsmith… Post up your file and I can check it against mine if you want…


Had the hole on the square end in the wrong location, file is updated and the hole is drilled. The other thing I needed to do was to get the insert to be the right thickness, good old undersized plywood. I had some shelf liner of the correct thickness so I taped it down and used the engraving bit to cut it out.

Still have to test it be things are looking better all the time.



yeah, plywood thickness is never fun. You could always use thicker than needed plywood and do a rabbet around the edge. That way you’d have finite control over the thickness of that rabbet…


Good to hear you are also a Shopsmith owner and user. I have known Ed for a while from the Shopsmith forum but haven’t seen any posts for you over there.


Yes I’ve been doing the rabbet by way of my overhead router and a dish bit but I like to try different things and ways and this was one of them. I really like to use UHMW but that stuff is expensive. Perhaps now that I have a proven design I might give that a go. Minor change to the drawing to get the design ready for cutting I would think.



My Shopsmith was my first real woodworking tool, and even though I have more tools in the shop now, I still use it for secondary setups!