How Would I Make a Firing Mechanism for a Catapult?

So I am trying to do this instructable here >>https://www.instructables.com/id/How-To-Build-A-Catapult/ and the author doesn't seem to be answering questions anymore. I am wondering if  anyone else knows what to do with the firing mechanism if using fibreglass pipe. Because if a hook is screwed in it, it seems like it would probably break out of it under the strain. Anyone have any ideas what i could do for the firing mechanism? Thanks!

Burf6 years ago
Make a clamp with a hook on it that clamps around the fiberglass pipe.
Something like this perhaps:

I would agree that the fiberglass would break. Instead use wood or metal for that part. You got to remember that all the torsion and stored energy is being held there. Catistrophic failure and/with possable personal injury is not something you want to gamble with.