Screaminhelo
Shade Tree Rocket Surgeon
- Joined
- Jan 30, 2013
- Messages
- 935
- Reaction score
- 4
While waiting for a dry day to put a clear coat on my Screamin' Green Meenie, I decided to explore an idea that had been growing in my mind.
While building the SGM, I started to wonder about a kitbash of sorts. I am a fan of short, fat rockets and if they are low'n'slow, that is even better. I figured that putting Kraken tube fins on an SGM could possibly produce an awesome short, fat, low'n'slow rocket so I started translating mindsim to OpenRocket. The first challenge was to sim contoured tube fins in OR. Fortunately, groups of three fins of the same contour effectively simulate a tube fin, the process is outlined here. The next challenge was to get a reasonable CG for a short, fat rocket so I referenced Peak of Flight Newsletter #154. The results from OR told a slightly different story than mindsim, so I decided that the wise approach would be to start small and adjust the design from there. The end goal is a 2.6 inch version, I just have a few things to figure out.
I used the fin templates from OR to transfer measurements to a 2 fin marking guide to produce a template for the tube fins.
We now have some parts to play with. I know that the Kraken has 4 fins but tube fins are cool so more is better in my book.
The OR file will get updated shortly. I used a nose cone that I had laying around, I think that it is the BNC-50Y but I am not certain of that. I will also over ride mass and CG when I get a chance to put the finishing touches on this little guy.
Motor mount and finished assembly to come shortly.
While building the SGM, I started to wonder about a kitbash of sorts. I am a fan of short, fat rockets and if they are low'n'slow, that is even better. I figured that putting Kraken tube fins on an SGM could possibly produce an awesome short, fat, low'n'slow rocket so I started translating mindsim to OpenRocket. The first challenge was to sim contoured tube fins in OR. Fortunately, groups of three fins of the same contour effectively simulate a tube fin, the process is outlined here. The next challenge was to get a reasonable CG for a short, fat rocket so I referenced Peak of Flight Newsletter #154. The results from OR told a slightly different story than mindsim, so I decided that the wise approach would be to start small and adjust the design from there. The end goal is a 2.6 inch version, I just have a few things to figure out.
I used the fin templates from OR to transfer measurements to a 2 fin marking guide to produce a template for the tube fins.
We now have some parts to play with. I know that the Kraken has 4 fins but tube fins are cool so more is better in my book.
The OR file will get updated shortly. I used a nose cone that I had laying around, I think that it is the BNC-50Y but I am not certain of that. I will also over ride mass and CG when I get a chance to put the finishing touches on this little guy.
Motor mount and finished assembly to come shortly.