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Old 10-22-2018, 05:53 PM
the mole's Avatar
the mole the mole is offline
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Join Date: Mar 2005
Location: Illinois
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Default Estes #1250 question

I'm wanting to build another Interceptor #1250 and I would like to shorten up the body tube from 18" to 15". I know I will have to add nose weight.


My question is has anyone ever built one with a shorter body tube?
Would it be necessary to change the motor size if I make this modification?

Thanks in advance for any advice.
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Old 10-22-2018, 07:03 PM
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Sprint60 Sprint60 is offline
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Well, I can't say that I've ever shortened an Interceptor, however I have shortened a rocket or two for various reasons (all unhappy ones) and it always came out OK.

Using a "bigger" engine may be required; it's hard to predict in this case since we can't know how much nose weight you'd need and there for the final weight is a guess. Since the weight at liftoff dictates the minimum thrust you can't know if a given engine is enough. My own Interceptor came out very heavy and barely flies on a C6-3. It's great on a D21-7 though! Goes like a banshee!

Have a simulator? Download a file; make some mods, run some sims. My guess is that three inches won't make a great deal of difference.
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Old 10-22-2018, 07:18 PM
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tbzep tbzep is offline
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Some of the guys here and on TRF loved to sim just about every kit. Throw out a bone and see if somebody has it simmed already. They can quickly shorten the length and see what it needs.

With all the hardware hanging on the rear and with those horizontal stabs moved forward few inches like they are, it may very well need some weight in the nose. Unfortunately, the nose is narrow so you may need more than with a more stubby nose where all the weight can be concentrated at the very tip.
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