29mm motor mount in a Estes Hi Flier XL

[RochonRockets]

Shear Pins, on a tiny Rocket like that?

Yeah, had to keep the one vent hole in the body tube lined up with the one in the nose cone. Shear pins were a bad idea.

 

[Handeman]

She really did scream up to amazing heights. I will build something better next time and not use shear pins again until I can figure out how to ground test.

Shear pins seem to be the rage on TRF lately. Everyone seems to say you have to use shear pins. I've been flying up to L motors with many DD flight for 7 years now and I only know of one, possibly two flights where I got main deployment during an apogee event. On both those cases I believe it was my fault for not setting things up right. I use friction fit for nose cones and apogee separation joints. When everything is set up and ready for the pad, pick the rocket up by the nose cone and shake it a few times. If joints separate, add tape.

For a small diameter motor eject rocket, I would never recommend shear pins. A snug fit on the nose cone is all you need.