Testing Joints - Results

Phew... well... that was rough.  I definitely need more practice using the routing table.  Here are the results:

Everything started off good.  First, the dado--pretty straight forward.  It did make a nice smooth cut.  As an added bonus, because the plywood is slightly less than 3/4" thick, it fits perfectly in the dado without having to make it wider.

Getting ready to make the dado

Finished

Plywood fits perfectly

Onto the cabinet door joints.  I used two pieces left over from my tests with stain/dye.  First, I beveled the would-be inner edges:

Beveled Edge

Next, I made the center groove and that's when everything started to go poorly.

Not pretty.

This groove should be nice and clean.  It's also about twice as deep as it should be.  The router bit actually started to pull itself out of the router.  Thankfully, it didn't come all the way out and nothing else happened.  I had the speed set too low and was probably trying to cut too much in one pass.  So after really tightening the bit what do I do on the very next cut?  Make the classic mistake of running the board along the wrong side of the bit and send the board flying into the basement wall.   Guh.

Moving on.  I made the rest of the cuts for the joint without issue until I got to the 45 degree groove.  I was hoping I could use the very top of a chamfer bit to make the groove but the cutting edge doesn't go all the way to the top.  I gave it a shot anyway and I wound up with this burnt mess.  (The wood is stained, not totally burnt, the burn marks are only at the top.)

You can see the charred edge right at the very top

So I would definitely need a different bit (or bits) to make this joint.  I did have better luck with the lock miter, though, still not a total success.

Top piece with just the mitered edge left

Things were looking pretty good until I had to do the mitered edge, again using the chamfer bit.  What I didn't think about was that I needed to use only the very widest part of the bit otherwise it would cut into the tongues.  This made it a bit more difficult to get the correct depth.  I also had trouble trimming the tongues to fit into the grooves.  Here's the end result:

Lock miter - First Attempt

Not the neatest looking joint.  Obviously some of my cuts were a bit off.  It was challenging getting the right depth for the bit and the fence.  Something to work on I guess.

So in review:  Dado in plywood is a go.  Cabinet door joints need special bits.  Lock miter joint is doable but will take some practice or purchasing of a different specialty bit.