PhxRocketeer
Well-Known Member
I have my L2 and I've built some high performance minimum designs as well as some just for fun types. Now I've decided to build an obnoxiously fat rocket for low flights. And I'm trying to do so relatively on the cheap and pretty custom. I also want to try some new techniques and push some boundaries to keep it relatively light. The goal is a simple to fly rocket that is dependable. I also would love to achieve a flying weight that can accommodate some 38mm motors so it's not always so $$. Aiming to get off a 6' rail with 30+ mph on smaller 350-500N motors (eg. I500, J425R DMS). The build plan currently looks like this (OR file at bottom), but I'm sure I'll end up modifying and missing some numbers.
Structural:
- 8" Sonotube (4ft)
- 3d printed Transition down to 5" (potential to do a FG version if I want to learn)
- 5" thick wall cardboard (~2ft)
- I may split this with a bulkhead if the BP charge is too large to pop the NC.
Fins: (still brainstorming)
- 3 fins because I'm lazy
- Complex sandwich: 2-3 layers of 6oz FG + 1/32" basswood + 3d printed skeleton + 1/32" basswood + 2-3 layers of 6oz FG
I need to calculate if this actually ends up lighter than a traditional plywood. The 3d print here just adds thickness, I may include spray foam as well if that is recommended.
- Will aim to do thru wall fins down to the MMT by using circular saw to cut out the bottom of the booster tube.
Nose:
- 12" 3d printed 'stubby' nose cone
- Will likely need some nose weight to add stability
Motor Mount: (expecting plenty of criticism here)
- 3d printer centering rings (Engineering analysis/testing in process)
- 54mm LOC MMT
- Retainer TBD
- BT-60 stuffer tube. I want to keep motor ejection an option for simple flights. I'll always have redundant ejection but prefer to avoid 2x electronics systems
Recovery:
- TBD 58-70" chute expected. Will be in the 5" section and eject the nose cone.
- Typically motor deploy + Eggtimer Quark for redundancy (2nd electronics if needed)
- Electronics will likely end up in a 3d printed case on the recovery line.
Paint:
- My friend recently vinyl wrapped a rocket for me and it turned out great and actually lighter than paint. So I'll probably do that again except for cone and fins
Currently I have the tubes and I'm planning to work on the booster section first. I've setup a test fixture so that I can optimize the design and weight of the 3d printed centering rings to keep the weight down. Any weight savings in the aft means additional savings in the nose weight I'll need to add. I have a nice test fixture setup for a static load test with very promising results. Aiming for ~1.5-2x margin for a K2050/ 500lb of thrust, which I would never actually fly in it anyway. I'll post some pics later if anyone is interested.
Looking forward to all of the negative feedback on 3d printed parts
. But I am looking for feedback on the fins, making an FG transition (thinking of using a 3d printed plug), or other areas of concern. usually I build quick, but I'm going to work on this one slowly and try to get it all right.

Structural:
- 8" Sonotube (4ft)
- 3d printed Transition down to 5" (potential to do a FG version if I want to learn)
- 5" thick wall cardboard (~2ft)
- I may split this with a bulkhead if the BP charge is too large to pop the NC.
Fins: (still brainstorming)
- 3 fins because I'm lazy
- Complex sandwich: 2-3 layers of 6oz FG + 1/32" basswood + 3d printed skeleton + 1/32" basswood + 2-3 layers of 6oz FG
I need to calculate if this actually ends up lighter than a traditional plywood. The 3d print here just adds thickness, I may include spray foam as well if that is recommended.
- Will aim to do thru wall fins down to the MMT by using circular saw to cut out the bottom of the booster tube.
Nose:
- 12" 3d printed 'stubby' nose cone
- Will likely need some nose weight to add stability
Motor Mount: (expecting plenty of criticism here)
- 3d printer centering rings (Engineering analysis/testing in process)
- 54mm LOC MMT
- Retainer TBD
- BT-60 stuffer tube. I want to keep motor ejection an option for simple flights. I'll always have redundant ejection but prefer to avoid 2x electronics systems
Recovery:
- TBD 58-70" chute expected. Will be in the 5" section and eject the nose cone.
- Typically motor deploy + Eggtimer Quark for redundancy (2nd electronics if needed)
- Electronics will likely end up in a 3d printed case on the recovery line.
Paint:
- My friend recently vinyl wrapped a rocket for me and it turned out great and actually lighter than paint. So I'll probably do that again except for cone and fins
Currently I have the tubes and I'm planning to work on the booster section first. I've setup a test fixture so that I can optimize the design and weight of the 3d printed centering rings to keep the weight down. Any weight savings in the aft means additional savings in the nose weight I'll need to add. I have a nice test fixture setup for a static load test with very promising results. Aiming for ~1.5-2x margin for a K2050/ 500lb of thrust, which I would never actually fly in it anyway. I'll post some pics later if anyone is interested.
Looking forward to all of the negative feedback on 3d printed parts

