Has anyone seen a smallish multi-stage N-1 rocket? I saw a video of a huge 1/16th scale one w/ 3 stages at LRDS 20 and have seen a few other paper and 3D models that all seem to be 1 stage. Is this possible to do as 2 or 3 stages?
The N-1 thread by @kuririn motivated me to go back to a 3D design I had started on a while back. I am redrawing / redesigning based on other STL files I can find, other models, and prototype pictures. I am shooting for good enough in my design to keep this pretty easy to print and light enough weight to launch w/ 3x D-engines in base (although people keep sending me better and better images or plans so I can improve detail). Design is currently around 30" long and on the order of magnitude of 240g of ABS filament for most parts (no tubes, centering rings, motor mounts, chute/shock chord). Counting on recessing motors where and if I can to help stabilize this.
I modeled this as best I could in OpenRocket. Component weights are not accurate since I will be 3D printing this but just wanted to see what default transitions showed for CP location, etc... This rough plan has 6oz of weight in nose to get this stable across all stages.
This is obviously an oddroc from OR's standpoint and not sure I can you model draggy fins like these by just making really thick / short fins like I did here. Interestingly modeling fins as normal 3cmx3cm .2mm thick fins only moves the CP back a little over 1cm.
Comparing CP calculation from OR to the ones published on Apogee's site for a couple of existing models suggests that this CP calculation is not impossible (at least for the full model):
The N-1 thread by @kuririn motivated me to go back to a 3D design I had started on a while back. I am redrawing / redesigning based on other STL files I can find, other models, and prototype pictures. I am shooting for good enough in my design to keep this pretty easy to print and light enough weight to launch w/ 3x D-engines in base (although people keep sending me better and better images or plans so I can improve detail). Design is currently around 30" long and on the order of magnitude of 240g of ABS filament for most parts (no tubes, centering rings, motor mounts, chute/shock chord). Counting on recessing motors where and if I can to help stabilize this.
I modeled this as best I could in OpenRocket. Component weights are not accurate since I will be 3D printing this but just wanted to see what default transitions showed for CP location, etc... This rough plan has 6oz of weight in nose to get this stable across all stages.
This is obviously an oddroc from OR's standpoint and not sure I can you model draggy fins like these by just making really thick / short fins like I did here. Interestingly modeling fins as normal 3cmx3cm .2mm thick fins only moves the CP back a little over 1cm.
Comparing CP calculation from OR to the ones published on Apogee's site for a couple of existing models suggests that this CP calculation is not impossible (at least for the full model):
- Altaria: 88cm long / CP 44.75cm (50.85%)
- Really Koo Stuff: 41.5" long / CP 30" (72.3%)
- My OR Sim: 68.2 cm long / CP 48.1 cm (70.5%)