Hi all, couple of covid related projects that have been completed...both are completely 3D printed projects. The 29mm project is interesting in it's numerous features and configurations with the design parameter that it would be suitable for a first time Level 1 HPR attempt.
Some info on RetroSpacer 24...it is completely 3D printed (PETG and PLA) features a 24mm motor mount and is capable of flying a 4G 24mm case. Motor retention is by Aeropack retainer, although I am toying with a design that is also 3D printed. It is single deploy and intended for motor eject, however, the payload is ample enough for a chute tender or some other protected device. It is stable and has been flown on an F-80 CTI reload
Some information on the RetroSpacer 29: This one is versatile.
1) 29mm motor mount (capable of flying a 29 6XL case)
2) F-I impulse flights
3) 5 fins, fully and easily field replaceable, in case of the inevitable fin damage on an attempt. And with access to your own 3D printer, customizable by the flyer.
4) 900 grams dry weight (this was a design requirement, in that the entire rocket could be printed from a single 1kg roll of plastic. While you may choose to use different colors, you are free to do what you like)
5) Dual Deploy, Single Deploy, extremely versatile for the flyer. Can be flown with motor backup, motor plugged, or just motor eject. Can be flown with drogue and main in either payload section. Can be flown with backup altimeter. Can be flown with chute tender in either section. It is currently configured with an RRC3 primary tethered to an RTx GPS/radio downlink, with or without or as an alternative and RRC2. It pretty much can be configured with any commercially available flight altimeter. (although I haven't tested them all)
6) the nose cone tip can be replaced, (although it shouldn't need it), but more importantly, nose weight can be easily added and secured by the flyer in the field.
7) Currently it utilizes an aeropack 29mm retainer, however the plan is to replace that with a fully 3D printed retainer.
8 ) It is stable at 0.9 cal dry, the stability increases to 1cal with the longer motors and stays the same with shorter motors. CP & CG were calculated by hand, verified in Open Rocket and confirmed by live testing.
I would love to launch this for Saturday, however, it is intended as a small HPR and thus it's maiden flight will have to wait.
