8/32 or 8-32 Pan Head Machine Screws

Hi all. Hope this is in the correct place and informative enough.

Brief overview of the Microjig Zeroplay Microbars

They come in single and double packs. Basically they allow you to create crosscut sleds or other accessories that require a mitre slot to operate – tablesaw, router table etc. Fairly simple functionality – two plastic strips overlay each other. Put in 3 small screws into angled slots and the plastic parts now slide over each other at a slight angle allowing you to alter the width. This allows you to finely tune them into the width of your mitre slot and ensure a very snug fit which means better accuracy on cutting etc. The single pack will likely suffice for a very small sled but for larger sleds and tables that have two mitre channels it is recommended you use more of them. I had 4 of them for my large crosscut sled.

Pros –

Cheap (ish) in the grand scale of things but can become expensive if you plan on making lots of different jigs and sleds.

Excellent fit across a wide range of tables and accessories that may not have standard sized slots. In about 5 minutes you will have them tuned in to your specific slot size.

Zero wiggle or side to side movement when done correctly.

Fits a wide range of slots including vertical wall and T-Slots.

Being plastic, won’t change shape, height, twist or warp due to humidity or warm / cold temps.

Easy to adjust. With hardwood runners - a tiny overshoot on the planer or sander = start again

Ideal for folks who don’t have access to hardwoods for runners or accurate enough equipment to rip them, plane them to be a snug fit etc or who have tried and struggle to get them fitted properly.

Easy to move them from old sleds to new sleds if you need to make a new one etc.

Cons – The following won’t be an issue for everyone but here is my experience

The screws that come to attach it to your sled / jig are UNC 8/32 and half an inch long. – Trying to source them here or trying to source longer ones has been fun over the festive period but Anzor do stock them.

You have to attach the plastic runners to the sled by screwing in from above I.e through the sled. Given there needs to be about 7mm protruding from beneath the sled in order to screw into the plastic bars and you also have to factor in a steel washer under the screw head, this means you need to drill a good old amount of the sled out, which on a 17m thick piece of ply or mdf meant not a lot was holding under the machine screw head.

They recommend / insist that you use a flat bottomed drill bit to drill the countersink holes. I have some forstner bits in larger sizes so tried a spade bit that pretty much destroyed the ply and ripped it out in chunks. Worked a bit better on the mdf. Recommends a half inch forstner which is about 12.7mm – good luck finding a 13mm forstner. Everywhere I looked they went from 12 to 15mm.

You also have to be good at measuring and marking prior to drilling as they need to be fairly exact – a way around this is to put the plastic runners into your slots, put some thin double sided tape on them, place the sled ontop, press down and lift back off. Then drill up through the brass nuts in the plastic runners with a 2mm drill which will mark your sled holes that require drilling out / deepening.

Can get expensive if you like to make lots of sleds.

Overall I am glad I tried them. I think they could do some more work on the install by allowing you to screw them in from below which would save a lot of time and effort etc but it looks like they created them 10 years ago and haven’t done much further work on the design. While most folks who buy them give them about an 80% rating, the downvotes are generally to do with the fussing around on the install of them, not the functionality. They seem to work well for most people. Happy to answer any other questions you may have. Thanks

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