OT: Router bit bearing question

[calebrichardson]

Originally Posted by smontanaro

I have a question for the woodworkers in the group. Maybe I am going about this all wrong. If so, perhaps you can steer me in the right direction. I want to cut a 3/8" square rabbet on the edges of four pieces of wood (making boxes from 3/4" plywood which has been cut to size). The idea is for the two rabbets on adjacent edges to interleave to create a stronger joint than a simple butt joint. I'm having trouble seeing how I'm going to cut these rabbets with my router and current bits.

I have a handful of bits for my router and only use it infrequently, so I'm hardly an expert. In particular, a I have a Freud rabbeting bit (# 32-100). It has a 1-1/4" diameter cutter and a 1/2" bearing, so it will cut a 3/4" deep rabbet. I want to cut a 3/8" x 3/8" rabbet. Adjusting the depth of the router is no problem, but I can't seem to see my way clear to the other side of the rabbet. (I assume if I had a router table this would be a no-brainer.) I thought I would just buy a 7/8" diameter bearing to enable the shallower cut, but that seems to be a (rotating) unicorn. I can't seem to find one with the right ID for the router bit (3/16", I believe). I would just cut the too-deep rabbet and trim to size with my flush cut bit, but I don't think that's going to work here (both rabbets will be too large in one dimension, so I can't glue up the joint then trim the excess).

That bit looks like it will cut a rabbit 3/8" wide (the width of the rabbet will be the distance from the edge of the bearing to the edge of the cutter) with an adjustable depth (which should be able to set to 3/8"), so not seeing what the problem is (other than the fact that your ply might not actually be 3/4" like someone else mentioned).

Also agree that for box construction, cutting rabbets on only 2/4 sides is easiest/better - your double rabbet solution isn't going to leave any space for screw heads, and I wouldn't do glue alone.

[C40_guy]

Originally Posted by smontanaro

I think the rabbeted joints will expose less end grain on the plywood (which is more expensive stuff from the local lumber yard, not the big box store stuff, and does measure a true 3/4" thick).

You are fortunate to have good quality wood. The stuff sold at the big box stores is absolute caca.

Can you run an external trim piece (or two) to cover the plywood end grains? Some pine trim could cover a multitude of sins.

[HenryA]

Glueing solid wood edging of the same species to the plywood is one way of hiding sawn plywood edges. About a 2 inch strip parallel to the grain of the face ply, glued and clamped. Use your router hand held to plane the two flush and sand ever so carefully. Then cut your joint in the solid wood.

Also, a picture of the napkin with your wife's sketch or the torn out magazine page she gave you as an example would be quite helpful. Is this a built in cabinet or is it free standing and viewable from all sides?

[CaptStash]

Do the half rabbit and get yourself a Kreg jig for pocket holes. The joints will be strong and the pockets can be filled as necessary. I've been doing face frames with the Kreg for years. It's invaluable. KREG JIG

CaptStash....