I’m trying to prototype a top that has an elliptical edge, rather than simply a round over (think of a surfboard edge that’s). Does anyone have any experience with this? I’m looking at a bit by Freud that’s a low angle, large diameter, round over bit, but with the guide bit needing a flat surface to rest on, this wouldn’t work when I flip and do the underside. I was thinking I could get around this by using the fence on the shaper instead, but wanted to see what others had done. Thanks!

I've done this with my cnc on a few table tops. It would be difficult and possibly dangerous to attempt a radius this large with a hand held router. Pushing a large table top around on a shaper wouldn't be easy either. It took about 20 minutes to shape this 2.25" thick walnut top using a 1/2" chipbreaker bit to rough it out, and a 3/8" ballnose to finish it.

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Thanks for the response duster. From a safety perspective, I don't see how this would be much different than raised panel, which we do with handhelds as well as on the shaper, but appreciate the heads up. Maybe I should have specified this is for a relatively small coffee table top. Since a guide bearing isn't an option, I'm leaning towards the shaper, but would love to hear from others who have done this.

I don't have a clue if this would work but, Amana sells a round over bit with a matching curved bearing they call an ultra glide radius bearing. Depending on the radius's involved if the bearing lines up with the small diameter cutting edge of the elliptical bit, it could possibly work.

You could have a shaper knife made and then make a fence that is the same curve as the table top. I have done this with 2 pieces of 3/4 baltic glued together. Same principle as the Hussey curved molding jig.

I have used a shaper for a cut like that with a round top on edge, curved cradle support, taller fence, and a feather board to hold it all. Just did it in a few light passes. Depends on how big the top is. I guess you could run a router with the base on the edge of the table and a large fence referencing off the face. Never gone that route but it may work.

Thanks for the great input! That Amana radius bit looks awesome. I should have mentioned that this will be for a rectangular top, so all straight edges. I found this bit last night from Orbit, and it looks like it might fit the bill perfectly. Merry Christmas!

Todd

You can always have a bit made to your specs? Should be fine to do by hand in several cuts.