Does anyone remember the old Estes "C" rails?
The rail button was nothing more than a nylon screw through the tube. The screw head was the "button" that slid into the rail.
I used that concept as a quick and dirty mini button for the club rail so I can fly this weekend.
Flew this at the URRG launch on a D21. This was a good engine as the rocket weighed nearly 14 oz.
The chute snagged on one internal "braces", so it came down horizontally. Landed on the soft dirt with no damage.
This was definitely a different build. If I ever do it again, I would ease up on the extra layers of cardstock, as it made the rocket too heavy. Of course, how many rockets need to have triangular tubes????