Sled - Purpose Specific, 1

[glenn bradley]

Got some time to finish up the big sled. 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 here but maybe the approach will help others.

The first picture shows a slot in the ¾ BB ply to accept the ZCI.
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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.
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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 double stick tape 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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Part 2 coming up . . . .

[glenn bradley]

Continueing on . .
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 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.
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Attach the front fence.
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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.
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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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Now using that slot I align the front fence and tighten it down.
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Oh darn, I need one more post.

[glenn bradley]

There’s a ZCI in the front fence as well. Once the fence is aligned, I finish the cut.
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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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Whew. OK, all done. I did the rotating panel / cut all four sides to add up the error test, everything's cool. Hope this helps someone out.

[Jim Becker]

Great pictorial, Glenn!

[Pete Brown]

Very nice. I would never have thought of putting a ZCI on a sled.

One question, the front of the ZCI looks like it is captured under the fence. Can you still remove it and get a new one in there?

Actually, I see the back is also captured. I assume you'd remove the fences to put a new ZCI in.

Pete

[glenn bradley]

Thanks! The front fence is removable. Part of how it adjusts. I just loosen it a bit, take out the bed's ZCI screws and slide it out. I've prepared some spares for the bed and the fence. Slide the new one in, replace the screws, cut it part way, align the fence and finish the cut. I actually put a bit of paste wax on the bed-ZCI where it slips under the rear fence to keep it from sticking in case it ends up there for awhile. One operational caution I should have mentioned; I don't haul this one around by the front fence like those that are glued down. It is handled from the sides. At about 25lbs it isn't a real problem even for a little guy like me. I'm 6 foot but only weigh a buck fifty-five.

[Pete Brown]

Thanks Glenn.

That's a nice sled. I threw together a quick one in melamine to get me out of a bind, and it didn't last long :P

[Bruce Wrenn]

I don't think I would refer to it as a "dummie block", but rather as a SMART BLOCK. Nice job and pictures.

[Peter Stahl]

There’s a ZCI in the front fence as well. Once the fence is aligned, I finish the cut.
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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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Whew. OK, all done. I did the rotating panel / cut all four sides to add up the error test, everything's cool. Hope this helps someone out.

Glenn, Excuse my ignorance but what is ZCI? Thanks.

[glenn bradley]

Zero Clearance Insert; prevents tearout and gives you a visual guide to exactly where the blade is going to cut. Easily replaceable if damaged or another blade or angle is required.

[Peter Stahl]

Zero Clearance Insert; prevents tearout and gives you a visual guide to exactly where the blade is going to cut. Easily replaceable if damaged or another blade or angle is required.

Thanks Glenn, couldn't get that acronym. I usually guess most of them. What is the ZCI made out of and also nice sled by the way. Gotta make one of them one of these days.

[Don Bullock]

Now that's what I call a great set of directions. Using the double sided tape for the rails has solved a problem that I was thinking through before I design and build one. I'm thinking of making one that is a combination of several nice sleds that I have seen on this forum lately. I've now added a few ideas frm your design to my ideas. Thanks for sharing your design and construction techniques.

[jonathan snyder]

Glen,

Could you please eloaborate a bit on the use of the T bolts. How do they make fence adjustements easier. I just can't follow!! :confused:

Thanks
Jonathan

[Bart Leetch]

How did you prepare the area for the ZCI & what material did you use for the ZCI?

[glenn bradley]

"How did you prepare the area for the ZCI & what material did you use for the ZCI?"

Bart,

I routed a 1/4" deep x 3" wide dado in the 3/4" BB ply bed and rear fence. ZCI is 1/4" Masonite. Mine happened to have white melamine on it and it increased visibility (plus it was laying around) so I used it. I used a scraper to fine tune the fit for the added "thickness" of the melamine but it is a small enough amount that regular 1/4" hardboard should be fine if I run out of the melamine covered spares I made during the build. It was easier to just go ahead and make the spares as I had the drill press stops already set up for the screw holes.

[glenn bradley]

"Could you please elaborate a bit on the use of the T bolts. How do they make fence adjustements easier."

Jonathan,

The t-bolts are 1/4". I made the holes in the fence a tight 1/4". The hole in the bed is 3/8". The bottom of the bed has an 1/8" deep slot centered on the 3/8" hole to allow the base of the t-bolt to move forward and backward to the extent that the 3/8" hole will allow the 1/4" bolt to move but does not allow it to turn. This is more than adequate play to adjust the fence.

I made the fence / t-bolt holes in a straight line left to right. The ability to shift the left side of the fence (for example) forward up to 1/16" from center and the right side back up to 1/16" from center allows for several degrees of adjustment. If you start somewhere close to 90*, this is a lot of adjustment. The photo showing the t-bolts in the OP just isn't very good but if you look closely you'll see the reliefe infrint and in back of the bolt t-head that is installed.

[David Cramer]

Excellent Glenn! Outstanding pictorial and a great shop project. Thanks for posting this. Very nice:) of you!

Dave