A while back my daughter and I built an air compressed paper rocket launcher similar to the one in this video, but with some of our own modifications. Cutting out the rocket was always the most time consuming part. So made a design that seems to work well. It’s designed to be cut on 80lb cardstock. The SVG file should split up into three parts. Here are the settings.
Fold/Glue lines: 500/10
It’s made to fit around a 1/2 inch launch tube with a little bit of space so that it slides off easily. I used a glue gun to put everything together. Even if you don’t build the launcher, it may be a fun project for a kid.