It took me a good hour and a half to get my 3/4 miter lock joint router bit setup, but I think this could work. Here is a picture of the final test of a miter lock joint using 3/4 MDF. The plan is to use a couple of these joints in Explorker2 for the media center doors and trim around the bed, to cover the slide-out cables.

First Decent Mitre Lock Joint
First Decent Mitre Lock Joint
First Decent Mitre Lock Joint

Here are some progress-type pictures. I’m not going to lie, I was close to giving up. It was very frustrating and I don’t think my router table is the best. I ended up sacrificing the fence, to get a close fit, and that made quite a big difference.

First Decent Mitre Lock Joint
First Decent Mitre Lock Joint
First Decent Mitre Lock Joint