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El Cheapo

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Can someone please run a quick Rocksim file for me to see if an AT Initiator would still be stable on, say, a G71 if I were to shorten the BT by about 5.5". Total BT length would be 18.5 " and total rocket lenght would be 33.5"

It suffered a nice zipper on an RMS reload that happened to have about a two second delay instead of seven. I'm not sure if I'll have enough room to pack the chute but if I can, atleast I'll be able to fly it until I can get some 2.6" tubing and coupler to fix it up. I never did get the decals on it so maybe I'll slap an "M" on the front of it and call it the Minitiator and leave it as is.

DSC02818.jpg
 

Iceman1979

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I have the initiator file at home but I'm at work now. If no one has done it by the time I get home I'll do it for you
 

El Cheapo

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Thanks. Atleast it looked good on the way up. I decided to fly it somewhat unfinished as the fins crackled horribly and didn't have time to sand them down again before the launch.

_MG_7534.jpg


_MG_7535.jpg
 

Richard

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I subtracted 5.5" from the airframe and the distance between the CG and CP was only 0.4 calibers without a motor loaded. With a G71R loaded, it was only 0.13 calibers.

Best Regards,
Richard
 

shreadvector

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Can someone please run a quick Rocksim file for me to see if an AT Initiator would still be stable on, say, a G71 if I were to shorten the BT by about 5.5". Total BT length would be 18.5 " and total rocket lenght would be 33.5"

It suffered a nice zipper on an RMS reload that happened to have about a two second delay instead of seven. I'm not sure if I'll have enough room to pack the chute but if I can, atleast I'll be able to fly it until I can get some 2.6" tubing and coupler to fix it up. I never did get the decals on it so maybe I'll slap an "M" on the front of it and call it the Minitiator and leave it as is.
Since you plan to use a new length of tube to repair the rocket (and probably make it longer?), and your primary wish is to be able to fly is now ASAP, you will want to do the safe and easy thing: Sand a bit of the paint off the damaged area and glue a cardboard doubler on the outside of the ripped area.
 

hardinlw

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I got a static margin of 0.07, so I think you need to wait until you get the parts.
 

El Cheapo

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Uhhhhhh, I still don't understand static margins and their numbers relative to stability. If the SM is .13, I should be fine, but if it's .07, we'll be doing loop-de-loops. Does that about sum it up?
 

KHamel

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Uhhhhhh, I still don't understand static margins and their numbers relative to stability. If the SM is .13, I should be fine, but if it's .07, we'll be doing loop-de-loops. Does that about sum it up?
The Center of Gravity (CG) should be at least 1 caliber (SM), in this case 2.6" in front of the Center of Pressure (CP) for stable flight. If the SM is .13 or .07 you will be doing loop-de-loops.

I hope this helps.
 
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