Sled question re: carriage bolts

When I built my temporary sled, I recessed the brick carriage bolts so they did not touch the workpiece. Not too surprisingly, seemed that there was issues with high sled to workpiece resistance. It almost made me wonder if the sled resistance could be a major factor in the accuracy. Similar to a violin bow on a string, or earthquakes on a faultline.

In any case, when I cut the final sled, using the design from the community garden, the carriage bolt heads are proud.

I was about to recess them with a drill, but then wondered if this is by design? If the sled is riding on four smoothish points at the bottom, the overall resistance of the sled might go down.

Recess or not??

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I say recess. I’d be more worried about scratching if it is riding on the bolts. Good thoughts though!


I recessed mine, the intention with the posted file is that the larger circle is cut as a pocket to recess the bolts. My concern with the bolt heads exposed would be that they might fall into holes in cut parts making the sled tilt


A lot of people have done things to the bottom of their sleds to reduce friction. You want some so it’s kind of a juggling act. I coated the bottom of mine with a couple coats of polyurethane to help it glide, lets saw dust fall off easier and to harden up the surface for durability. It seems to be working fine. I also made sure to heavily sand and chamfer all edges on the bottom of the sled ( outside sled edge and any other hole or counterbore).


Has anyone tried this stuff yet? It seems like a few strips of this applied to the bottom of your sled would solve any friction issues.


I purchased this in 9in wide. I’ll let you know how it goes.

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I haven’t cut anything yet but this stuff is slick. 2 sheets of the 9 inch covered the entire sled. Moving it around the board with GC you can definitely tell that it has way less friction then my old sled. My only hang up was trying to figure out how to fold the edges around without creating crinkles.

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Heat gun?

you must have a lot of extra, and it’s expensive stuff. If it ends up being worthwhile, you should sell the rest on the forum!

2 rolls of the 3/4 inch width tape that I linked should be enough to cover the sled, it would just take many strips.

36*5*.75= 135 square inches of tape per roll

Sled is 18 inches in diameter, so radius is 9 inches
π*9^2= approx. 254.5 square inches

Although I’m not sure you’d need to cover the whole sled, just using a single roll might be enough, it’s only .010 inches thick, so there’s not much chance for it to get stuck on the edges of the tape, if you spaced it out a bit.

The cheaper and wider versions of the tape are thinner, at .005 and .007 inches thick. I’m not sure if that would help, as we might want it to be thicker so that it wears through less quickly. Normally, you use this stuff on drawers or anywhere wood is rubbing against wood, although I’ve also heard of it being used on metal against metal parts : for example, if you have enough clearance, it might be used to make the router’s Z axis move more smoothly.

edit: markdown is annoying when doing math

edit 2:

I just looked a round a bit on amazon and see that they also have 12 inch square pieces of this stuff, 2 of those would also work if you don’t want to line up a bunch of 3/4 inch strips, although it would require some interesting cutting. Search for “UHMW adhesive” on amazon to see them