RockSim 7.0- Subassembly

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Well-Known Member
Jul 23, 2002
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Okay. can anyone explain how to use this feature? I have looked at the help topics, videos, and searched the apogee site until I turned blue. HELP
it does actually work but it is not intuitive and the info available doesn't help.

you might take a look at Apogee's newsletter #118, there is a pretty good step-by-step explanation in there.

basically what you do is:

1 - in some design, add a sub-assembly.
2 - add the parts you want, under the sub-assembly tree
3 - when the parts are all right, go back to the tree and select the sub-assembly node. click edit on it, then click "save to database".

Careful, remember what the file name is and what directory you saved it in.

4 - when you want to use the subassembly, in another rocket, click in the parts tree and select "subassembly" in the Add New Component area in the Rocket Design Components tab. This will pop up a dialog, click "choose from database" and then go find that file.

the Rocksim Sub Assembly files have extension .rsa. that extension isn't registered by Rocksim so there's no icon for it. bad rocksim, bad :)

it would be great if we started making a subassembly library, maybe put it on EMRR or something.

seems like managing the "database" of subassemblies might take a bit of diligence with directories.

hope that helps!!
Originally posted by cls
it does actually work but it is not intuitive and the info available doesn't help.

hope that helps!!

Great. I was starting to think I was going nuts! I built a subassembly, saved it, then when I went to retrieve it...I CAN"T FIND it...or it doesn't come up whne I click on it. I'll check out the letter.
Thanks CLS:D
CLS-Thanks. I think I was hoping for something that apparantly I can't do. I was trying to attach a side mounted tube that had a motor and 1 fin and some other components. CAN"T DO IT!! Not yet anyway. :kill:

You can attach a side mounted tube that has fins on it in RockSim version 7! See my fins on fins simulation article in the Apogee Peak of Flight Newsletter Issue #113 and My Side Pod simulation article in issue #119

Create the side pod tubes as I describe. When you do this, you need to use the fin mount concept I describe in the fins on fins article e.g. use a word processor program to change the side pod tube from an inside tube to an outside tube which you can then assign fins to. Attached is a modified Estes Gemini DC model I did this for. Note that RockSim draws the side pod fins on the main centerline even though they have the information associated with them to be mounted on the side pods.

The sub assembly will still only work for the motor mount portion in the side pods.

Bruce S. Levison, NAR #69055
Bruce, you are the total awesome studly rocksim GOD!!! seriously!
I do agree with Flying_Silverado in that a hosted chat session would be a really neat idea. If you decide to work with the moderators, I might be able to help out and set up a web based session where a "lecture" could be demonstrated.

No promises, as I would have to do some serious arm twisting. Possibly we could get Apogee to underwrite the remote session costs :D
Seminar! In a chat room? I could not figure out how to get the chat room up an running on my computer!

This sounds fun though, how do we arrange for this to happen and at what time?

A demonstrated lecture; will you guys put up with my misspellings and dyslexia. I recently wrote and 4 page article without spell check and at least I am not batting 1000 on misspellings, but pretty close to 500. I am famous for misspelling the word "of" in my high school senior composition class.

I should have read this thread first tonight!

Bruce S. Levison, NAR #69055
There are ways that it is possible for a person to be working on a PC stepping thru some teaching/demonstations while others watch, and in some cases interact. We do this occasionally where I work, however there are fees often involved, The cost is why I thought Apogee might be interested in sponsoring it. I know there are other suppliers who akso frequent the forum and they may want to get a piece of the promotion. It would be a challenge to set up, however if there is enough interest, I'd be willing to pitch in and help coordinate.

I've read that one of the super moderators, CTULANKO is listed as a network architect. Given that, he may have some insight on how we might make this happen.

I really feel if we can start educating people on the parts of rocketry that lie beyond a simple BP engine an $10 Estes airframe, the possibilities to demonstrate how the hobby can lead to an expansion by showing the real educational aspect of what we do.
We have a setup like this at work as well. I'll ask around about it, but I believe licensing fees are prohibitive for the solution we use (but then again, we have 450-500 people working remotely off the same live database, so it may not be appropriate either).
OK I understand how you are getting Rocsim to display these structures but now my question is.
How accurate would the CP calculations ect.. be?
Would RS still consider these as inside structures when doing calcs.?
RockSim is actually calculating the CP based on the side pods!
I address the CP and Cd issues of side pods in the Apogee Peak of Flight Newletter Issue 119;

I think these CP values are pretty close to reality; I am actually waiting on some wind tunnel data to confirm these simulations. The theory I used is based on a mathematical argument that compairs side pods, tube fins and ring tails to flat fins.

Bruce S. Levison, NAR #69055