Here’s the template I made.
For some reason, it came out about 1/16th too short when wrapped around the pipe. Maybe the paper thickness? Anyway, I just adjusted the grid size and reprinted it. After Getting it all lined up and square, I punched through paper at the crosshairs. I also slid the paper cylinder back just a hair and marked with a sharpie the bit that protruded. I filed the marked area off with a hand file the get the end perfectly square to the holes. ..well that’s the theory. All I know is that it’s square now as far as I can tell.
The drill press didn’t seem accurate enough for this job, so I cleared off the mill table and drilled the holes on there. The only V-Blocks I could find in the shop were rusty and un-even, so I made some wood ones quickly on the table saw.
As per the plan, I fixed the end cap on, the center drilled, drilled and tapped the holes. It took most of Saturday night, which my girlfriend wasn’t too psyched about.
I probably should have been more careful about squaring and securing the end cap in the pipe. It may have gotten slightly skewed. I’m not going to worry about it though, since perfect squareness isn’t critical here.
I also noticed another mistake.. When I reprinted the template, I accidentally made it with only 7 screw holes, not 12. I think it’ll still be strong enough though. I’ll have to do a little FEA before I test fire it.
Here’s the finished assembly. I made more mistakes on this part than I’d like, but eh, live and learn. It should work perfectly, and it looks awesome. 🙂