Shopsmith Forums

I am getting ready to make a new cross cut sled. The old one works but I am making some changes to incorporate some features that I have seen on others. Mainly, I want a replaceable ZCI and I may incorporate a miter feature.

I am going to make the runners rather than use steel ones from Shopsmith. This means that I will loose the "locking t" feature but I think I can live with that.

But I had a question.

When I cut the hardwood runners, does it make a difference which way the grain runs?

I was planning on using the surface planer to get a piece of wood down to the thickness (47/64") that would just slide in the miter track and then simply rip off pieces of the proper height.

I also plan to cut two dados in the bottom of the sled for these runners. My thought being that these would help to prevent the runners from changing position.

I would think you would want the grain to run the length of the runners for maximum lateral strength. I totally agree with cutting dados to insert the runners into to further increase a strength and eliminate any shifting of their position. Sounds like a great plan.

Quarter sawn wood (the grain running vertically) will move less across the width than plain sawn wood, so that would be the better choice. But, with slats that narrow, there probably wouldn't be much movement in any case.

Regarding cutting dados, I'd expect that trying to get a perfect match between the saw table slots and dados in the bottom of the sled would be a challenge. As an alternative, you could glue wooden slats to the sled bottom to prevent movement. In any event, just screwing the slats to the bottom should be enough.

pennview wrote:Quarter sawn wood (the grain running vertically) will move less across the width than plain sawn wood, so that would be the better choice. But, with slats that narrow, there probably wouldn't be much movement in any case.

Regarding cutting dados, I'd expect that trying to get a perfect match between the saw table slots and dados in the bottom of the sled would be a challenge.

The grain running vertically I think is my best bet. I have one sled with the grain in the runners being horizontal. I think that from time to time the runners twist just a little and I get some binding.

Getting precise measurements will be a challenge. Two dados exactly .734" wide separated by exactly 7" and exactly parallel.

A problem that I have with my current sled is that the miter bars get just a tad out of parallel and the sled binds. I can force it through but force is never a good thing. To be really safe, that sled runners need to glide through the tracks as smooth as silk.

This is really why I was thinking about dados in the bottom of the sled. If I get those right to start with (yes, a BIG IF), they should remain perfect for the rest of my life time.

One way to cut the dados is with a router and a short pattern bit. Make your runners longer than the bottom of the sled so that you can drop them into the slots and then clamp them to the bottom of the sled front and back. Or, you could use a couple of screws in each runner to temporarily attach them to the bottom of the sled. Then transfer pencil lines to the bottom of the sled. Now attach a straight edge along the lines and use the pattern bit to cut the dados. Use a 1/2" diameter pattern bit.

Dusty, HERE is a YouTube video (5 Cuts to a "Perfect" Cross-Cut Sled) by William Ng showing how he does his Cross-Cut Sled. Specifically how he makes the runners and "perfectly" aligns the fence. It may give you some ideas about yours.

curiousgeorge wrote:Dusty, HERE is a YouTube video (5 Cuts to a "Perfect" Cross-Cut Sled) by William Ng showing how he does his Cross-Cut Sled. Specifically how he makes the runners and "perfectly" aligns the fence. It may give you some ideas about yours.

That is an excellent video and I wish I could take about a years' worth of classes from him. He is an excellent instructor.

I have bookmarked this video.

Thanks for posting this, George.

BTW My miter tracks and presume all Mark V miter tracks are .738" wide and 11/32" deep at the shallowest level. My tracks are 7 1/64" apart (inside to inside).

You are very welcome, Dusty. If you want to attend some of his classes all you have to do is go next door. His school is in southern California (that's next door, right? ). In case you are actually interested here is the URL for his school... William Ng School of Fine Woodworking.

Had to view the video on how to properly chuck a drill bit. This guy is good. Learn something new every day.

http://wnwoodworkingschool.com/how-to-p ... drill-bit/

wrdavis wrote:Had to view the video on how to properly chuck a drill bit. This guy is good. Learn something new every day.

http://wnwoodworkingschool.com/how-to-p ... drill-bit/

Do to recent problems I had to check it out