Thread: Making zero clearance inserts

I have looked at getting phenolic inserts as well but my saw is old as the hills so I can only find them from the US. Currently running about 45AUD before shipping and I need at least 4. Big nope.

A flush trim bit is certainly the way to make zero clearance inserts. As to what the most suitable material would be this can depend on the depth and support offered by the throat in the saw. What type of saw do you have bueller?

Jet JTAS-10 - from back when safety was an afterthought and the signature Jet colour was blue!

IIRC there are just four ears protruding which the insert rests on.

Originally Posted by aldav

A flush trim bit is certainly the way to make zero clearance inserts. As to what the most suitable material would be this can depend on the depth and support offered by the throat in the saw. What type of saw do you have bueller?

Actually just remembered I have all my manuals on PDF.



Terrible photo as it's a scanned manual but you can make out the 4 spots where it rests.

Thinking about fitting these with the MJ splitter as well, want to use the steel one but apparently they don't work with phenolic. Will need to do some reading on their page.

Edit: scratch that, the Steel ones work fine with phenolic plates now that they've updated the install instructions.

what about MDF? Not the nicest to work with, but it's dense and would be stable. I need to knock up a few too so may give it a try.

Probably not the worst idea. I was thinking phenolic but Microjig recommend a drill press to drill them which I don't have soooo MDF is probably the way to go.

See post #15 in this thread - Baker machinery 305mm

The material is very dense and stable. It's about the right thickness to sit straight on the existing supports. You can either drill and tap the supports to screw the insert down (some masking tape may be necessary to achieve a nice flat and level fit) or, if you have good strong dust extraction, tap the insert and use the existing grub screws to adjust the fit. The suction of the dust extraction will hold the insert down.

The last time I made inserts I made 8. I think I've got one unused one left and some of the others are looking pretty second rate. If you have and use a dado stack it pays to make a few at a time.

Cheers mate, sound like a plan!

My brother too has an old Jet table saw, and like yours it also doesn't have a riving knife. I made a couple of ZCIs for him last year. I used 18mm MDF. The process was along the lines of:
1. Trace the existing insert onto the MDF (I did four).
2. Bandsaw/jigsaw out each blank ~5 mm oversize.
3. Screw the existing insert onto the blank as a template.
4. Using a flush trim router bit, shape it perfectly.
5. I needed to route out the four areas where the insert seats on the table tabs as it was less than the MDC thickness. I over removed material so that it would set ~2 mm lower than the table.
6. Waxed each table tab, and put a blob of hot glue on the "mating" parts of the insert.
7. Whilst the glue is still hot and pliable, placed the insert in place, and pressed down with flat edges to align perfectly with the table top, and waited for the hot glue to set.
8. Put the fence half way over the new insert to hold it down, turn on the saw, and raise the blade through the insert.
9. Cut a slot for a splitter and install.

The MDF works very well, and lasts too. If you're so inclined, a couple of coats of varnish provide a spectacularly smooth and robust finish.

Originally Posted by bueller

Probably not the worst idea. I was thinking phenolic but Microjig recommend a drill press to drill them which I don't have soooo MDF is probably the way to go.

You’re welcome to use mine if you want to.
I cut the slot in mine by raising the blade through the blank plate but any other slots we can mill with the metal mill.
BTW I made mine out of Al plate.

Thanks Bob, legend!

Looks like I'll be making two sizes of ZCIs, just pulled the trigger on a new table saw. Had too many near misses with mine and decided to beat the price rise from the falling dollar.