qquake2k
Captain Low-N-Slow
- Joined
- Jan 26, 2010
- Messages
- 13,574
- Reaction score
- 65
Like a lot of you, I like stubby rockets. And also like a lot of you, I like upscales. I've been thinking for a long time of building a Fat Boy upscale. But there are a ton of them already out there, and I decided to do something different. I've never seen an upscale of the Quest Cobalt. Mine will be an approximately 3.5x upscale, based on LOC 5.54" tubing. It will have a 54mm motor mount, and I'll also make a 38mm adapter for it.
I decided to build it slightly longer than scale, for the stability. The original Cobalt is 7.5" long, which would make the upscale about 26.25". Mine will be about 27.5" long, a little over an inch longer. But that extra 1.25" means I'll only need 8oz of nose weight, instead of 20oz or more. That's a significant weight savings. I've also reshaped the fins slightly, to increase the stability further.
View attachment cobalt_5.5_38mm5.ork
View attachment cobalt_5.5_54mm5.ork
I decided to build it slightly longer than scale, for the stability. The original Cobalt is 7.5" long, which would make the upscale about 26.25". Mine will be about 27.5" long, a little over an inch longer. But that extra 1.25" means I'll only need 8oz of nose weight, instead of 20oz or more. That's a significant weight savings. I've also reshaped the fins slightly, to increase the stability further.
View attachment cobalt_5.5_38mm5.ork
View attachment cobalt_5.5_54mm5.ork
Last edited: