I’m about to cut my final sled and I’ve looked at a few iterations, including the one with the centering jig (brilliant.)
I’m wondering though why I have not seen one with a counterbore for the plate of the router. Seems to me that would allow for the whole sled to be at one level except for the counterbore for the carriage bolts. This seems to me to provide better stability over the 18in diameter.
I have made up a .nc file for it, but I’m wondering if I am missing something before I go wasting wood.
I’m not sure what you are suggesting, but you don’t use the plate. You attach the base directly to the top of the plywood.
I think hes suggesting counter sinking the router base into the plywood. I thought about doing this as well but for stability and alignment purposes.
I never did cut a final sled. I just used a compass and made multiple circles on a piece of 1/2 inch ply (gives an extra 1/4 inch of z travel), drilled a 1/4 inch hole in the center, put a 1/4 in drill bit in the router to center and marked the base mounting holes, used the circles to properly align the ring kit and mark the mounting holes, cut the 18inch circle out with a 5 minute router circle jig made out of spare hardboard scrap, used a hole saw to cut out the open area for the router bit, used a round over bit on all bottom edges. Checked center accuracy by using a square to mark inside diameter of ring once it was mounted, drilled some 1/16 holes along this line and used a caliper to measure the distance from the outside edge of the 1/16 drill shank to the outside edge of the 1/4 drill shank mounted in router and ended up with a variance of about .015 inch or less. Used the circles to mark brick mounting locations, works great. Total time to create this sled (not counting excessive cig breaks and locating misc tools and scrap that I think was relocated by some of @mooselake 's swamp rats that were on vacation out here) was about 75 minutes.
Now I realize some people may only have a drill and a handsaw in their toolbox but I think they should have a caliper in any case (to properly measure thickness of their stock), a compass is easy enough to fake (i mean make) out of scrap (or even a cheap plastic ruler with some holes drilled in it) and a hole saw is usually less than $7 (this hole doesn’t need to be perfect anyway, use your router if need be)
Took the base plate for the router and threw it in the fancy Ridgid case that came with the router along with handles and z axis knob and then promptly misplaced the case (some more of mooselake’s swamp rat mischief I think). I did reinstall the handle bolts to hold the z axis tension bungie cord (which I made out of the nice shock cord and zip ties Bar sent with the kit since I am using fancy imported 2 liter Dr Pepper bottles 1/3 full of exotic tap water to use to counter weight the chain slack (yes, I am using the over the top chain config)