routing a rabbet

[Mark Hoffman]

I am making an oak counter and will be installing a cooktop flush. The corners of the cooktop have a 3/8" radius. The rabbet needs to be 1/2" wide to support the lip of the cooktop. To get a rabbet that wide, the bit i'm using has a diameter of 1 3/8" 1/2" is the largest the bit is capable of. That said, the corner will not produce a 3/8" radius to match the cooktop. I'm glueing up the counter with the proper sized cutout prior to routing the rabbet. How can i get that 3/8" corner? just free hand it after i rout the bulk of the rabbet?

[Jamie Buxton]

You could use a different bit. You could use a straight bit of 3/4" diameter, and make a template to guide it. For instance, you could cut a rectangular hole in a sheet of plywood, and use that hole to guide the outside of the router base. Or you could build a rectangular hole from four pieces of scrap, and again use the hole to guide the outside of the router base. Or you could put a template guide on the router base, and run that guide against a template which is a rectangular hole.

[Mark Hoffman]

aha!! that's a great idea. for some reason i was just drawing a blank. probably because i moved recently and haven't been in the shop for about a year. this is my first project in my new place. I don't have a 3/4" bit but i do have a slightly undersized plywood bit that will be very close. Thanks!

[Jim Becker]

Make a template and use a top bearing cutter that has the same diameter as the cutter. The template should be the correct size for the cooktop to slip into (be sure there's a slight allowance so it doesn't bind...like the thickness of a piece of paper all around. Route the perimeter and then offset the cutter slightly to get the remainder toward the inside of the opening if your cutter isn't wide enough. Clean up the corners manually to match the cooktop.

[Cameron Wood]

Use the rabbeting bit that you have, then freehand the corners with a smaller router bit, a carving gouge, or a forstner bit.

[Maurice Mcmurry]

Use the rabbeting bit that you have, then freehand the corners with a smaller router bit, a carving gouge, or a forstner bit.

I have a Dermel with a DIY router base I use just as Cameron describes. With an OptiVisor on and having not had too much coffee I use it freehand.

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