I was struggling to come up with a way that I could prototype the cam roller bellcranks and associated tubes. I decided to make them out of brass so that I could solder them together using regular plumbing solder. I happened to have a scrap of brass sheet left over from some long-distant project, and it looks like it's going to work out nicely.

Using the step drill to drill the pivot holes up to the appropriate size in order to accept the brass tubing.

Bellcranks for the cam rollers are complete. The 2nd one from the bottom was a bit cropped, but no matter...that won't affect the prototype.

The actuation bellcrank needs to be thicker, so I soldered two layers of brass sheet together.

...then drilled the holes and sanded the outside.

The cam plates need a 10-32 tapped hole in the top so that a pushrod can extend upward to the forward end of the popup tipup arms.