Wow, thanks again for everyone taking time to share all of this information. It sure is helpful. As I said I imagine there will be additional sleds in my future after this initial endeavor. I hope to finish one tomorrow. Jack
Wow, thanks again for everyone taking time to share all of this information. It sure is helpful. As I said I imagine there will be additional sleds in my future after this initial endeavor. I hope to finish one tomorrow. Jack
I just bought a 24 x 24x 3/8" sheet of UHMW for sled runners, figure that will be a lifetime supply. I was quoted $40, but when I went in to pick it up the guy spontaneously dropped the price to $30. FYI - it comes in either black or white, I was told that the white is food safe, not so the black. The white is more expensive, and less durable due to the increased processing, so I got the black. I'll try to refrain from eating any of it. If you live in a larger city, you can probably find it locally through a plastics distributor, there were several who stock it here.
The nice thing about having an Incra fence, I was able to dial in the width of each slot to the nearest thousandth (left is a little wider than the right), and got a perfect fit for each on the first try. I'll be making three sleds, one large and one small crosscut, and two miter sleds, the latter three for box making. I will be following the William NG video for the two standard crosscut and a miter crosscut sled, and another design from Fine Woodworking for the one for vertical miters.
Dan
Last edited by Dan Forman; 09-11-2017 at 1:38 AM.
Eternity is an awfully long time, especially toward the end.
-Woody Allen-
Critiques on works posted are always welcome
Not exactly.
For a large sled two runners can distribute loads over twice the runner attachment area (and number of fasteners) of just one runner, as when the outer edges (for example) function as a single wide runner. Additionally dual runners minimize the leverage which could be applied to a singe runner.
"Anything seems possible when you don't know what you're doing."
I've found that two runners work better than one - that was the reason for my earlier recommendation. I feel that the setup is much more stable with two runners. I can see how there is logic behind the idea that one runner will get the job done, but in my own use, I found my single runner sleds (more than a couple of them) to be a bit on the loose side. Perhaps this was to a deficiency in my manufacturing technique - so be it - the double runner eliminated the issues I had.
One advantage of a single runner sled is that you could actually use both miter slots - dedicate one for normal square cuts, and setup the other for 45 degree cuts (for example). Can't do that with a double runner sled.
Nah, I'm just trying to help people from falling into the trap "if one runner is good two have got to be better", The first sled I ever built was a two runner. I built it in the hot dry summer. Come winter it wouldn't drop into the TS slots. Literature I have read predict plywood size changes (not thickness) of approximately 0.1 percent for a 40 to 75 percent humidity change. Runner to runner that's .01 inches. My current sled has .004 in free play. Nuff said?
I don't like the way wood, UMHW or worst of all aluminum slide against cast iron. I have always used 3/4" X 3/8" cold rolled steel for all my sleds and jigs. It always slides smoothly. And I only use one runner. The price, when purchased from a metal supplier is often cheaper than buying UHMW runners from the usual WW suppliers, though you may need to buy it 10' or longer lengths- it will last forever.
Miter gauges, including those with long fence extensions only have and need one runner. Two are not needed and just too much of a pain to get aligned perfectly.
Also, if you are using a runner that is subject to wear, I suggest you cut a shallow dado in the bottom of the sled first. That way when it is time to replace the bar, the new one will align automatically.
On small infrequently used sleds I used one wooden runner. On my large sleds that saw tonnes of use I used aluminum bar stock and two runners because it was easy to tweak and when it got sloppy I'd use a centre punch to tighten everything up. Set one runner up for the square and then fix the second runner. One runner just as good as two? On a full sized sled? Nope.
I need to make a new sled. I've used oak runners and I had problems with them seizing up due to expansion. For my next one I'll try quarter-sawn instead.
I actually HATE making table saw sleds because I really struggle with the process to make it perfectly square. Yes, I've seen the YouTube videos where you rotate a piece of wood 4 times taking a cut to measure the total amount off. But trying to nudge a fence into alignment with that whole screw method is just tortuous for me.
If anyone is reading, any recommend plans for a fence that is adjustable?
Not set up for a chop saw as I see them as site trim tools and break out saws but the stock that I often use is too large as I don\t have a sliding unit. So yes larger pieces of lumber and doors. No one ever told me my tablesaw couldn't do it and as it turns out it always did! Thankfully I now have a larger slider. Crosscut sleds are one of my favourite shop built items!
I am not trying to toss a wrench in the gears here but I cant believe how many ppl like the wood runners ! I dont like them and would not suggest anything other then adjustable nylon screw style bar. https://www.amazon.com/Kreg-KMS7303-...bar+adjustable
For me the $30 bucks was well worth the time saved trying to make a perfect wood runner that does not bind at some point in the slide. I was very surprised at how well the adjustable ones work.
I made 14 through double wedged tenon doors like this at a very hi end quality using this kind of track and those are some very heavy cope cuts that nearly all came out perfect.