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
[OP]
Contributor
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
Member
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
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Only one runner at a time is in contact with the TS slot, so there is not added strength from a second runner.Originally Posted by Matt Day
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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."
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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.
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Do you own stock of one runner sleds Dan? This is the third time in this thread you've been adamant that one runner is the way to go.
Contributor
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?
Contributor
Yes please
Member
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.
Member
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.
Member
What are you trying to cut on you sled? a 10' long 2X12? Something more appropriately cut with a chop/slider saw?
Member
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?
Contributor
You can make final adjustments with a hand plane.
"Anything seems possible when you don't know what you're doing."
Member
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!
Member
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.
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