I figure this is a good place to start for a first post. This past Sunday I flew my recently completed LOC IRIS for my L1 cert flight. I was concerned with the speed the rocket was going to leave the rail, so to avoid any issues there I went with an H550ST DMS from Aerotech adjusted for an 11 second delay. Probably a bit overkill for a cert flight, but the motor mount and retainer held.
The retainer was 3D printed with CF PLA. It gives the option of using a 3D printed ring that screws into the mount or clamping your standard thrust ring down like most retention systems. I had some concerns with the strength as well as heating from the motor, but there were no signs of stress or damage on the retainer ring, so it seems to have worked really well. I’ll be sure to keep an eye on it as I fly it more, but printing a new retaining ring is simple, cheap and quick so if I notice any fatigue I’ll be sure to swap it out.
The main benefit I see with this mount over your standard Aeropack/commercial retainer is the aerodynamic profile. It provides a smooth transition between the rocket body and nozzle. Does it actually do much as far as lowering drag? I’m not sure, but some testing may be fun. At the very least I think it looks pretty good.
The flight itself was uneventful. Launch was straight with no wobble, chute deployed right at apogee (Open Rocket has been very good to me in suggesting delay times) and we recovered it without too much wind drift. The hyperlink below leads to a short video from the launch.
A short drive in the truck and we found it without damage.