Making Cheap Adjustable Miter Bars

[Patrick Varley]

Finding the right DIY miter bars for jigs has been something of my own white whale over the past few years. I've tried everything: UHMW, aluminum, hardwood, store bought, homemade. Never been quite happy with things though. So I set down my requirements:
1) Affordable
2) Stable (I have a garage shop in a place with significant humidity swings)
3) Easy to work
4) Adjustable
5) Ideally re-usable

So I read all the threads I could find on it, and came up with my solution which I am happy to say worked better than I could imagine. Just thought I'd share it here for others who have been on a similar hunt. Stability and re-usability knocked out hardwood. I liked the aluminum bars, and made a few with bar stock from McMaster. However the width isn't exactly right, leading to an annoying process of trying to grind them to the right size. UHMW is stable and cheap, but it deforms and isn't necessarily adjustable. What I really wanted was something like the Rockler adjustable miter bars...but I didn't want to pay $30/each.

My solution ended up being: A $5 scrap of Corian from the local cabinet shop and some nylon set screws. As it turns out, the Corian cuts just fine with a 60-tooth blade, and is easily drilled and tapped for the set screws. Result:10 adjustable miter bars for a total cost of $12.

Attachment 446251Attachment 446252

[glenn bradley]

I just used a set of UHMW runners for the third time. I use through holes with counter bores from below. Screws every 4 inches or less since UHMW is flexible. Tightening the round head screws in the counter bores makes the sides swell a bit for a custom fit if required. I also use a shoulder plane and / or a card scraper to customize the fit.

That being said I have used everything but, steel for jigs; straight grained oak, aluminum, commercial runners of a few types. All have worked well for me. If you are having trouble no matter what I would check your miter slots. Some are irregular along their length, not parallel, etc. I use steel on the miter gauges.

[Bruce Wrenn]

I've used aluminum ( 3/8 X 3/4) from Enco, now MSC. It only comes in 24" lengths. From local steel supplier, I buy 3/8 X 3/4 1018 flat steel bars in ten foot lengths. Both of these are a perfect fit into my miter slots. If too loose, I can drill and tap them for brass or nylon tipped set screws.

[Lee Schierer]

I got tired of replacing and adjusting the nylon set screws in my Kreg crosscut guide to eliminate the side to side play. I backed them all off and applied a strip of UHMW tape tehe full length of the bar. It has been several years and the bar doesn't wiggle in the miter slot and still slides smoothly. Self adhesive Uhmw tape comes in various thicknesses. I have that is .005" and .003" thick.