# number of runners on crosscut sled?



## JesseTutt (Aug 15, 2012)

I have always built my table saw crosscut sleds with two runners, one for each miter slot. I figured that this would help eliminate any racking and keep the back fence at a right angle to the saw blade.

I regularly see designs of a sled with only one runner in a single miter slot.

Why would I want a single runner instead of two? The only possibility I can think of would be to be able to run the sled in either miter one for when the blade is at 90 degrees and the other when at 45 degrees.


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## Fuzzy (Jun 25, 2007)

Another possibility would be that the two slots are not perfectly parallel to each other … I had an old Craftsman saw back in the 70's that had such a problem. A 2-runner sled would bind up at one end or the other.


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## crank49 (Apr 7, 2010)

Fuzzy, that's no reason to discard one of the runners, that's a reason to discard the saw.


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## Nicky (Mar 13, 2007)

Jesse,

I would think that this is a matter of personal choice. In watching the New Yankee workshop over the years Norm used a "panel cutting sled". It only had one runner because it was only used to support the work on one side of the blade. If you're using a cross-cut sled, that spans both sides of the blade I would think that you would have better support and some redundancy. I'm sure a crosscut sled could be used with 1 runner, but two seems better, at least to me.


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## a1Jim (Aug 9, 2008)

I think it depends on what the jig is used for it's design and size as to how many miter grooves you use.


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## helluvawreck (Jul 21, 2010)

I have sleds with both one and two runners. It depends on what the sled is used for. However, for a large crosscut sled I think it should have two.

helluvawreck aka Charles
http://woodworkingexpo.wordpress.com


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## joeyinsouthaustin (Sep 22, 2012)

I agree with "it depends on what the jig is used for" Sleds in my shop used for larger crosscutting, tend to have two, smaller sleds used for angles, finger joint, etc. tend to have one.


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## JesseTutt (Aug 15, 2012)

Assuming that the table saw has two parallel miter slots, is there any reason why you could not make the sled large enough and use two sliders?


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## MrRon (Jul 9, 2009)

Expansion and contraction can cause sleds using two runners to bind in the miter slots. One runner sleds avoid this.and if made well, are just as accurate as a two runner sled.


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## JesseTutt (Aug 15, 2012)

I don't understand. I have always used aluminum or plastic for runners and plywood, MDF, or Melamine for the sled bottom. Will plywood, MDF or Melamine expand or contract enough to cause binding?


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## REO (Sep 20, 2012)

one runner if properly fitted will eliminate racking as well as two. racking is allowed because of the clearance between slot and rail. two runners will allow just as much misalignment. two runners just gives you twice as much chance to take up the clearance by pitting one against the other.


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## PittsburghTim (Jan 16, 2012)

Don't understand why it matters so long as the runner is properly fitted? Tenoning jigs have one runner and the good ones allow for extremely accurate cutting. I have an Osbourne miter gauge that is extremely accurate and it only uses on runner. I think that it depends on your application, just like Jim stated earlier.

Tim


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