Leon shares his new adventure: The other day, I started to help a friend whose employees had to take some time off. Seems there were orders for many, many picture frames to be made. I began with these sides.
Then into the gluing/pinning machine where they were assembled.
By locking two pieces squarely in the jig, the angled pin is driven up from the bottom in the corner. That secures the joint perfectly.
Here's one completed with all four corners joined.