Large Sled Part 1

glenn bradley

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Built this large sled for a specific purpose. Same principle as medium sized ones but built to help me through a project that will involve several large panels. I have made a few of these but they were always slam-bang jobs so, I decided to put a little effort into this one as I suppose it will be around awhile. I didn't go as far as some of the beautiful sleds we’ve all seen but maybe the approach will help others.

Some of the quality on the photos shows that my true calling (if any) is not photography. If anyone needs better (or different) shots, PM me with your email and I can send you full quality attachments.

The first picture shows a slot in the ¾ BB ply to accept the ZCI.

1 slot for ZCI.jpg

Next pic is a little fine-tuning of the depth with a scraper. No that's not the ZCI strip, just a scrap for measuring.

2 scraper tune.jpg

The rails are oak. I’ve always used UHMW before with good luck but the local shop was out of any material long enough. I use the TS fence as a guide and lower the base onto them to get a good positioning.

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Trim the extra tape if any. The idea is for these to slide, not snag.

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I put thin strips of scrap in the miter slots to raise the oak slides just above the table so the tape will stick.

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Oak guide rails in place. Screws are the real attachment method but I leave the tape. This has never been an issue. I should mention again that I place the raised and pre-taped runners in the slots, position the fence, place the side of the sled-bed against the fence and lower onto the rails/tape. This makes this step pretty reliableas far as lining up the blade with the ZCI. I should mention that I cut the ZCI slot off-center to allow me to raplace the long ZCI and use the blade at other angles or with a dado.

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Attach the front fence; this one is glued on. remember, once you make your first cut you have two hlaves held together by the front and rear fence only. Don't scrimp on height or length. DAMHIKT.

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I use T-bolts a-la Gary Rogowski. This makes the fence very easy to align or re-align. The fence is also plenty thick in case I need to re-flatten it. It is hard to see in the pic but the recess for the t-bolt head is oval to prevent turning and longer than the length of the t-bolt head to allow forward and backward movement during alignment.

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With the rear fence on and the front fence sorta on I cut the ZCI almost back to the front fence.

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And on to part 2 . . .
 
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Large Sled Part 2

Now using that slot I align the front fence and tighten it down.

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There’s a ZCI in the front fence as well. Once the fence is aligned, I finish the cut. The reason I wait until the fence is dead on is that the front fence ZCI can be used to align your work. I make several spares; if one becomes worn I replace it and re-cut because I love having that 'right at the cut' visual to help me align my cut mark. I always recheck the fence if I'm replaceing the insert. It just seems as good a time as any but I have never had to re-adjust yet (oh great, now I put a whammy on my sled).

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I add a full “dummy block”. I’ve seen others that just keep your thumb out of the way. I’m all for total coverage at the blades exit point.

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I have made smaller versions of this guy at about half the front to rear depth. I keep the 36" width as I feel that is about the minimum for me. Smaller pieces I am usually able to use my miter gauge for. If I was going to do a lot of repeated small pieces I would probably take the time to put together a small sled for that. They are very reliable and save way more time than they take to build.
 
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Nice job.. I like the inserts too. The t-nuts, did you countersink the nut heads into the fence?? Also, are you using nylock nuts or did you use lock washers? It looks like you have a larger hole and some clearance for the t-bolt to float in and a proper hole in the fence, right??
 
I didn't want to 'over discuss' the assembly and bore people but wanted to discuss some more detail if folks were curious so, good question and I'm glad to expand on it. The t-bolts are 1/4" x 20 "toilet bolts". The hole in the sled-bed is a 3/8" through hole for each t-bolt. The recess on the underside of these 3/8" holes is 1/8" deep for clearance for the t-bolt head while passing over the TS table. The recesses are 1/2" wide to keep the t-bolt from spinning and 1 1/8" long. This combined with the 3/8" through holes allows forward and backward movement during fence adjustment. This is true for all four t-bolts, two on each side of the eventual cut down the ZCI area of the sled bed.

The holes in the fence that accept the shafts of the t-bolts are 1/4" for a nice tight fit. I wanted all adjustment to occur at the heads of the t-bolts, not the shafts as they should stay as true to 90* with the sled bed as possible.

There are recesses along the top of the fence to allow a 1/4" flat washer and the nylon lock nuts to recess into the fence. Be sure to make your recesses not only big enough to accept the flat washers but to accept your tightening tool (a nut driver in my case) as well.

The fence is a little over 2" thick with the t-bolt holes 7/8" on center from the rear face of the fence. This allows adequate material if a t-track is to be dadoed into the front of the fence for a stop block. It also leaves plenty of material if changes in the season take my fence a bit away from straight. I can just take it off, run it across the jointer, put it back on and square it up.

As mentioned, I knocked out a couple more of these (one for dad, one for me) that were smaller for general sled work. I reach for the smaller one quite a bit and keep the big one against the wall for that occasional large panel square-up.

One caution on use is to pick up the sled by anything other than the fence. Remember it is adjustable and you want it to stay true once set up. I used to put fence handles on my other sleds with glued down fences and developed the habit of picking them up by these fence handles. On this design I grab them by the sides just as a caution.
 
Nice sled, and excellent write-up. I like the idea of the t-bolts for adjustment. I've got an oversized cutting board in progress that could really use a sled bigger than the one I currently have. Like Stu, I'm tight for storage space, but I think I'm going to have to find a place to store a big one, then get busy and make one.
 
If its any help, I put little rubber feet on the rear edge (while facing the blade) of the sled bed. I store it on this end in front of my DC. The little feet keep him from dancing away from the DC which I actually lean it against. I did the same for a smaller sled but put the feet on the side.

This area is normally open for access to the dust bin but I don't mind using it to store this large flat beast. Its easy enough to move out of the way when I have to empty the bin. Here's a pic of them in hibernation. You'll notice the cut on the small sled is off center more drastically than on the large as I use him for 45* cuts with a different set of ZCI's.
 

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