Hardwood runners on a crosscut sled...

[Bobby O'Neal]

How much trouble with expansion should be expected? How many of you use prefab adjustable miter runners?

[brett gallmeyer]

I use uhmw. No expansion issues and if u want to adjust the fit just sand or run a screw into them so they expand.

[Jamie Buxton]

My sleds have wood runners. I have a thickness planer, so it is easy to make them exactly the width I want. I also have a shoulder plane, so if the runner gets sticky, I can take a few thou off.

Tip: put only one runner on the sled. One is sufficient to keep the sled straight. If you have two runners, and the sled gets sticky, you can't figure out which of the four faces to plane.

[John Coloccia]

Wood expands and contracts in predictable ways for the most part. Choose a piece of mahogany that is nearly perfectly flatsawn, and you won't have serious problems. A piece of metal, though, is cheaply attained through Woodcraft (for example) and is far better for this application IMHO and is what I use. I can adjust the little set screws to get it perfect, and when it drifts I can adjust them back to perfection.

I have jigs that use both miter slots, made up of plywood with metal runners, and it always seems to fit perfectly with no problems.

[Peter Quinn]

I have used maple sliced to be QS across its width for runners with good results, and have also used some hard exotics like jatoba or bubinga. i have also drilled and tapped the maple runners with nylon 8-32 set screws that allow me to take out any slop and adjust going forward. I tap them just like I would metal, and use my metal taps to do so. More recently I bought some cold rolled steel from on line metals .com and made my own for a big TS sliding jig. i have also used the aluminum rails from woodcraft and like those very much for their adjustability. I made some jigs at work using a product called Boat Board that is very much like UHMW plastic, and that works great for runners too.

I like to run shallow dados in the base of my jigs, maybe 1/16" depth, to key in the runners, regardless of the material they are made of. It helps to keep them straight going forward and makes installation a breeze. It work s for two rail sleds too but you basically have to make two separate sides and bridge them after an initial cut.

[Bobby O'Neal]

John, I like your thoughts. Using two runners seems the best to me. It looks like it would be easy to make square and keep things consistent. Also, for the price and durability of aluminum, why not, eh?

Besides, I have tried a couple different attempts at building a sled with miserable, profanity laced results. Those attempts were using Norm's plan with one runner. Its been several months since I tried to make one and since I've only been at this hobby for about a year, I feel like i'm way ahead of where I was months ago so it should go smoothly this time.

[Bill Huber]

I am in Texas and its dry most of the time but when it not will thing swell. I tried wood runner but they did not last long before I pulled them off and replaced them with the Incra 24". They are not the cheapest out there but I sure like them, light and easy to adjust.

My sled has 2 runners on it, I just think its better that way.

http://www.incra.com/product_jfc_miterslider.htm

[Mitch Barker]

I use wood runners on many sleds. Never really a problem. A shoulder plane simplifies getting the fit just right. Don't forget to apply some paste wax on the runners and the bottom of the sled. Topcote works well too.

Here's an interesting product I saw the other day. Never used it. Just looked interesting.

http://microjig.com/products/zeroplay-guide-bar/

Mitch

[Phil Thien]

Wood didn't work that great for me.

Here is a previous post on how I used UHMW:

http://www.sawmillcreek.org/showthread.php?82788-Finally-a-better-sled-runner&highlight=runner

[glenn bradley]

This will vary with your environment. I have used UHMW, Incra aluminum pre-made and straight grained white oak. All are in use and all work fine year round. I'm in SoCal; this would probably not be true in Atlanta or Honolulu though.

[Joe Scharle]

One thing I hate when I'm working on a project is to have to stop and fix one of my jigs/sleds. I started using metal runners a few years ago and that problem went away.

[Alan Lightstone]

I've used those zero-play guide bars on a few sleds. They work quite well. Easier to use, IMHO, then wood.

[Matthew Hills]

I use uhmw. No expansion issues and if u want to adjust the fit just sand or run a screw into them so they expand.

I also use UHMW (picked up a sample pack from my local Woodcraft).
Works great; has maintained a consistently good fit and moves well over the last couple of years.

Matt

[Jerry Bruette]

I took Bill Hubers advice and used the Incra's. Doesn't matter if it's July or January in Northeast Wi. they don't change.

Jerry