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Old 09-24-2018, 10:20 AM
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tbzep tbzep is offline
Dazed and Confused
 
Join Date: Mar 2005
Location: TN
Posts: 11,610
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Quote:
Originally Posted by Andy63
Yep. Going with a 29mm mount (using an LT-115 series tube). The nearest ring off of erockets that matches the 1.4" diameter of the FSI is the SEM-CR-115-150P at 1.5". But when you do the math off the scale drawings, the narrowest part of the tail cone is 14" which works out to be 1.75" @ 1/8" scale. Its quite perplexing as to why the tail cones are/were made so narrow.

I've come to realize the FSI kit is only semi-scale. I just thought it may be a little closer in scale than it is (the nose cone is perfect). Just one of these things you find out when you nit-pick the details. End the end, I'll probably put it together knowing the fins are a bit undersized as well as the tail cone and appreciate it for what is it - still a **** good looking sounding rocket!

I was thinking backwards on your 1.75" vs 1.4" numbers and was thinking it was underscaled.

I'm guessing they had one or two reasons for it. They probably didn't want a big thick heavy hunk of wood back there so they may have cut the angle sharper to remove some mass. Possibly a better reason is that sometimes things don't look right to the eyeball when done to scale, so they exaggerate them. The Centuri Saturns (and more recent versions of the Estes models) are an example. Most people like them because you can see the corrugations better, but they are considerably exaggerated. Of course, there is another option. They could have just screwed up.
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