Open rocket design question

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Troy3003

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I'm new to open rocket and still figuring it out. I have two questions for now.

1) how would you add in a motor adaptor like the aeropack 3854.

2) The original sim i found here to start working from has a zero mass transition located on the rear of the design, i assume to introduce extra drag for the simulation. If im building stock would i be better off to remove that from the design?
 

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  • LOC 5.5 Goblin.rkt
    14.4 KB · Views: 12
The adapter can be simulated by adding an internal tube and centering rings to the stock MMT. I believe those adapters are aluminum, but could be wrong.
The zero mass transition is there to simulate base drag for CP. With it, your flight characteristics will be off, remove for a better simulation of altitude and off the rail speed.
 
This is a short/stubby design, in which base drag contributes significantly to the Cp determination. OpenRocket does not model this effect natively, and it has been found that adding this massless transition helps to determine Cp more accurately. So, what you should do is:
1) Leave it there for figuring out where Cp is, if you need to do this, and
2) Remove it when you're doing the flight simulation to determine altitude, etc.
 
The words "sim", "found", and the file format being a .rkt makes me guess that it came from RocketReviews. I always urge caution when using files from there as there's no standard of quality for them. I'm sure that they're safe enough, but not necessarily that accurate. Still I'd doublecheck everything on a file I download from there (especially fin templates).
 
I forgot the name so i did a search again. It was created by Arsenal78. Only one i have found for the Loc 5.5" version.
I'm going to verify the file specifics against my parts. I just got the kit the other day but haven't had time to do anything besides a check to make sure it was all there and no shipping damage.
 
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