RockSim Tips & Tricks

[Tau Zero]

Elsewhere on YORF, Don "Barone" Fent and that Craig McGraw boy :chuckle: observed:Maybe we need a "RockSim" section here in the forum under "Workbench" where people who have a RockSim specific question can ask it and those really knowledgable about the subject can inform us. I know there's bits and pieces posted all over this forum but maybe a dedicated section would be helpful? [SNIP] it would be really nice to find all the info in one spot instead of surfing the forum trying to find it.....Maybe we should create a new thread...? :cool:So here we go. :D

In the interest of keeping the content of this particular thread on-topic :eek: , please limit your questions and answers to the following loose but specific parameters ;) :

Q. "I have RockSim [specify version here]. How do you make ring and tube fins sim accurately?"

A. "That will require borrowing a technique pioneered by Bruce S. 'teflonrocketry1' Levison, who is a qualified RockSim guru. Here's how Bruce does it..."


Each of us who have been bashing around with RockSim for a version or three :rolleyes: have either managed to come up with our own little tricks, or learned and borrowed from other people (or each other). And migrating between versions can require some adjustments, too. ("What the hey? I *used* to be able to do that with the old version of RockSim? What gives with *this?*"


So here we go. (Parent's voice) "I don't think I need to remind you boys and girls to play nice." ;)


Cheers,

[CPMcGraw]

A compound component is where you merge the properties of two simple database components together to create a third component, which you cannot save to the database. The attached files show an example of this. I have created a transition to use with Estes BT-50 and BT-60 tubes, and which has a 1" wide base on the BT-60 end. The shoulder for the transition is still available as it would be with any other.

The idea is relatively uncomplicated. Start with your transition. Go into the edit dialog for the transition, and click the "Shoulder" tab. Locate the "Length" for the end you are adding the extension to, and increase the value found here by the length of the extension. Change the name of the component to some descriptive identifyer, and add "Front" in parentheses. Make sure the Material is "Balsa" (or whichever material you want it to be). Close this dialog. The shoulder is now very long on the 2D and 3D display screens.

Now, add a 1" length of standard tubing (in this case, BT-60) to that end of the transition. Open up the editor dialog for that piece of tube, and locate the "Material" drop-down box. Change the type of material, and the part name to match that of the original cone section, but add "Rear" in parentheses. Close the dialog.

You now have the equivalent of a single-piece component.

[James Pierson]

Although a new thread about Rocksim is great however ;) I personally would like to see a new Forum Title under the Workbench section. Something like "Rocksim Asylum" or something of that nature. Besides we could have many threads under such an area. We definely need to get all the DATA files in a neat thread along with the component parts, tips and tricks, etc... Just my two cents worth, JP.

We would be the first Forum to have an exclusive "Rocksim" thread to my knowledge.

James Pierson
NAR# 77907

[CPMcGraw]

Although a new thread about Rocksim is great however ;) I personally would like to see a new Forum Title under the Workbench section. Something like "Rocksim Asylum" or something of that nature. Besides we could have many threads under such an area. We definely need to get all the DATA files in a neat thread along with the component parts, tips and tricks, etc... Just my two cents worth, JP.

We would be the first Forum to have an exclusive "Rocksim" thread to my knowledge.

James Pierson
NAR# 77907

Some have also mentioned "SpaceCad", so maybe a "Software" section with "RockSim" and "SpaceCad" as primary sub-threads. I know Scott could add them, but the question is do we need a "top-level domain" type of category (like Workbench, or Swap Shop) for this? I'm 50-50 with the idea. Most of us use RockSim, but I've never seen anything drawn up with SpaceCad. Does anyone here actually have it installed, and use it?

Might be something to have some discussions about, before setting it up.

[Mark II]

Hey, Jay! What do you say? :D

OK, here's my first dilemma. I whipped up a RockSim 8 clone of the Centuri Groove Tube #KA-11. Everything is done per the plans found at JimZ's site, and it is built with parts from Semroc. The result matches up pretty well with the rocket's vital statistics shown in the 1972 Centuri catalog at Ninfinger.

The recommended engines are A8-3, B4-4 and C6-5.

Here are my results:

Length: 18.35"
Diameter: 0.908" (ST-8)
Fin Span: 2.724"
Weight: 1.5 oz

All simulations use a 48" x 1/8" rod.

A8-3........79.6'......Dv 42.6 FPS
B4-4........99.2'......Dv 70.6 FPS
C6-5........105.6'.....Dv n/a

The rocket is unstable using all recommended engines. :(

What am I missing?

Mark \\.

[CPMcGraw]

Although a new thread about Rocksim is great however ;) I personally would like to see a new Forum Title under the Workbench section. Something like "Rocksim Asylum" or something of that nature. Besides we could have many threads under such an area. We definely need to get all the DATA files in a neat thread along with the component parts, tips and tricks, etc... Just my two cents worth, JP.

We would be the first Forum to have an exclusive "Rocksim" thread to my knowledge.

James Pierson
NAR# 77907

Getting back to your idea, James...

Having a thread under the "Workbench" category... RockSim technical discussions do tend to get buried in other threads, don't they? Maybe we do need a way to bring them out into the sunshine. What do you think about having a whole category (like Workbench and Swap Shop) dedicated to RockSim, or "Software", with RockSim as a sub-category?

Sorry for this habit of thinking out loud... :o

[CPMcGraw]

OK, here's my first dilemma. I whipped up a RockSim 8 clone of the Centuri Groove Tube #KA-11. Everything is done per the plans found at JimZ's site, and it is built with parts from Semroc. The result matches up pretty well with the rocket's vital statistics shown in the 1972 Centuri catalog at Ninfinger.

The recommended engines are A8-3, B4-4 and C6-5.

Here are my results:

Length: 18.35"
Diameter: 0.908" (ST-8)
Fin Span: 2.724"
Weight: 1.5 oz

All simulations use a 48" x 1/8" rod.

[/font]
A8-3........79.6'......Dv 42.6 FPS
B4-4........99.2'......Dv 70.6 FPS
C6-5........105.6'.....Dv n/a
[/b]


I just fed the data into my copy, and got the same results, so it's RockSim not liking something. Let me look at one of my tube-fins and see what I did differently. I'll post later...

It's 1:37 in the morning, and my brain is whining... :eek:

[Tau Zero]

Hey, Jay! What do you say? :D

OK, here's my first dilemma. I whipped up a RockSim 8 clone of the Centuri Groove Tube #KA-11. Everything is done per the plans found at JimZ's site, and it is built with parts from Semroc. The result matches up pretty well with the rocket's vital statistics shown in the 1972 Centuri catalog at Ninfinger.

The recommended engines are A8-3, B4-4 and C6-5. [SNIP]

The rocket is unstable using all recommended engines. :(

What am I missing?Here's how the aforementioned Bruce S. Levison did it in RockSim 7 (see attached file originally downloaded from The Rocketry Forum [TRF]). He did it to contrast how inaccurate RockSim 8 was with its tube fin calculations.

Of course, now that I look at it, I realize *I* may have been misinterpreting the way Bruce models tube fins. :o On the other hand, I think I have *ring* fins down okay, since Bruce was kind enough to look over an early version of my Tau Zero design and tweak it so it actually worked. :cool:


Cheers,

[Tau Zero]

"Think BIG Jay"Jim, that *really* hurts my head. :rolleyes: :chuckle:


Although a new thread about Rocksim is great however ;) I personally would like to see a new Forum Title under the Workbench section. Something like "Rocksim Asylum" or something of that nature. Besides we could have many threads under such an area. We definely need to get all the DATA files in a neat thread along with the component parts, tips and tricks, etc... Having a thread under the "Workbench" category... RockSim technical discussions do tend to get buried in other threads, don't they? Maybe we do need a way to bring them out into the sunshine. What do you think about having a whole category (like Workbench and Swap Shop) dedicated to RockSim, or "Software", with RockSim as a sub-category?Gentlemen,

I humbly recommend that we blend your suggestions thusly:

Workbench / Software / RockSim Asylum (with multiple threads)


"Gather ye inmates, while ye may..." :eek:


LTV Scott ;) , is this doable? And do we need any further discussion on the matter?



Submitted for your consideration,

[Mark II]

Here's how the aforementioned Bruce S. Levison did it in RockSim 7 (see attached file originally downloaded from The Rocketry Forum [TRF]). He did it to contrast how inaccurate RockSim 8 was with its tube fin calculations.

Of course, now that I look at it, I realize *I* may have been misinterpreting the way Bruce models tube fins. :o On the other hand, I think I have *ring* fins down okay, since Bruce was kind enough to look over an early version of my Tau Zero design and tweak it so it actually worked. :cool:


Cheers,
OK, Bruce Levison's RS8 version looks almost identical to mine, yet his version works (at least for BP A's and B's) and mine doesn't. I don't see what the critical difference is. Can anyone point out what I am missing?

I encountered this same problem when I tried to simulate a Quest Totally Tubular. That's what caused me to think that there was something very odd about the way that RS does tube fins. :eek:

BTW, what are those extra fin-like structures in the tubes in the RS 7 version of Bruce's file? What the heck is that all about? :confused: And what is that blue star-like structure at the base of the main BT in your file?

Finally, you mention ring fins. Does RS do something weird with them, too? (See next post.)

I like RockSim's concept, its execution and its polish. I want to keep this on topic and find answers about these particular things, in order to gain some insight and learn a trick or two or a tip that I can use in the future.

If Scott creates a new subsection under the Workbench as James and Jay propose, then I'd be happy to confine the discussion of this one issue to one particular thread within it. That would work well, I think.

I think that the proposed subsection should be confined to talking about specific techniques, solving specific problems and answering specific questions. IOW, "hands-on" stuff. (Conceptual ranting about the program itself or anything else, which I am as prone to doing as anyone else, could still be done in other places, just not there. ;) )

Mark \\.

[Mark II]

Jay,

You mentioned that Bruce Levison had to tweak the ring fin in your Tau Zero design file in ways that you, the rocket's designer, don't even understand, in order to get it right. Does that mean that you had to alter something in the actual design of the physical Tau Zero as a result? Or does it mean that the TZ's design file had to be altered to match the results you obtained with your physical model? Is this an area where the designer may need to do some tweaking of the program's calculations in order to bring them in line with real-world performance? If so, are there any particular guidelines for doing so?

Mark \\.

P. S. Jay - I prefer plasma cannons myself - they might be more wasteful of energy, but they get the job done a whole lot quicker! :D

[Ltvscout]

Ok. I've added a new forum section called RockSim Asylum as requested. I placed it under Workbench vs creating a whole new parent forum. If I suddenly see an avalanche of users using/posting SpaceCAD files, I can add its own section at that time.

If you guys want me to change the description for this new section, please let me know.

[Tau Zero]

P. S. Jay - I prefer plasma cannons myself - they might be more wasteful of energy, but they get the job done a whole lot quicker! :DMark,

Here's how the original exchange "went down" back in August 2006:


DeanHFox: Jay, I really like this design so far, but the sci-fi geek in me is screaming, "it needs fin-tip laser cannons!"

I'm thinking "launch lugs with dowels in them" ala the Canaroc Scorpion.

CenturiGuy: We could call it the Dean H Fox "Sci-Fi Geek" Ion Cannon Mod.

JRThro: But Dean asked for *laser* cannons. If you install *ion* cannons, you'll have to reroute the warp manifold at the very least.

DeanHFox: Hey, "Ion" cannons, "Laser" cannons, "Thermal-Phaser-Pulse-Tuned-Plasma" cannons, they're all the same when you're looking down the barrell of one!

BOY, those tip-cannons make that design sexier. If they make it to Semroc's "production" version, I'm glad to have contributed a little something. You even got the LENGTH I was thinking about right on the money!


So as my mom would say, "Pick your poison." :eek: ;) :D


Cheers,

[Mark II]

Mark,

Here's how the original exchange "went down" back in August 2006:


DeanHFox: Jay, I really like this design so far, but the sci-fi geek in me is screaming, "it needs fin-tip laser cannons!"

I'm thinking "launch lugs with dowels in them" ala the Canaroc Scorpion.

CenturiGuy: We could call it the Dean H Fox "Sci-Fi Geek" Ion Cannon Mod.

JRThro: But Dean asked for *laser* cannons. If you install *ion* cannons, you'll have to reroute the warp manifold at the very least.

DeanHFox: Hey, "Ion" cannons, "Laser" cannons, "Thermal-Phaser-Pulse-Tuned-Plasma" cannons, they're all the same when you're looking down the barrell of one!

BOY, those tip-cannons make that design sexier. If they make it to Semroc's "production" version, I'm glad to have contributed a little something. You even got the LENGTH I was thinking about right on the money!


So as my mom would say, "Pick your poison." :eek: ;) :D


Cheers,
JG and Semroc: Giving The People What They Want!

(Sounds Kinda Kink-ish, doesn't it?)

So what about those tube-fin designs? (Keeping this discussion focused laser-like on target.)

Mark \\. ("Johnny Thunder" :D )

[Tau Zero]

JG and Semroc: Giving The People What They Want!

(Sounds Kinda Kink-ish, doesn't it?) :chuckle: ;) :D


So what about those tube-fin designs? (Keeping this discussion focused laser-like on target.)Mark,

You sent me back to some of my ancient (2005-06) RockSim files to see what I could figure out. Additionally, I've been researching Apogee's "Peak of Flight" Newsletters to see if I can understand Bruce's techniques. You can download issues 113 (fins on fins) and 117 (sidepods), which explain how he did it in RockSim 7.

I'll start a separate thread, now that Scott Hansen gave us our own separate asylum. :eek: :cool:

To quote Carl M. quoting Mike Myers as Middle-Aged Man, "I'm workin' on it!" :rolleyes:


Cheers,

[Mark II]

:chuckle: ;) :D


Mark,

You sent me back to some of my ancient (2005-06) RockSim files to see what I could figure out. Additionally, I've been researching Apogee's "Peak of Flight" Newsletters to see if I can understand Bruce's techniques. You can download issues 113 (fins on fins) and 117 (sidepods), which explain how he did it in RockSim 7.
Yeah, I think that I've get those somewhere...

I'll start a separate thread, now that Scott Hansen gave us our own separate asylum. :eek: :cool:
Thanks!

To quote Carl M. quoting Mike Myers as Middle-Aged Man, "I'm workin' on it!" :rolleyes:
Keep Drinkin' Buddy by your side (even though he needs to make frequent pit stops) and watch out for Independent Woman! :chuckle:

Cheers,That's what DB said! :D

Mark \\.

[K'Tesh]

Umm... Shouldn't this be stickied? This was the absolute last post in this sub-forum, and I'd think it should be the absolute first for new users. Then again, I don't use RocSim.

[teflonrocketry1]

You might also find Bruce Levison on this forum to help you with your RockSim simulations. I am the #1 Certified Expert RockSim user, a title and avatar given to me several years ago by Tim Van Milligan at Apogee Rockets. Since I am "certified", I guess I belong in the RockSim Asylum.

[teflonrocketry1]

Bruce Levison's Model Rocketry Bibliography:

"Teflon Rocketry: Use of New Inexpensive Teflon Materials in Rocketry," By Bruce S. Levison Sport Rocketry, 40 (1997), 38.

"The Tripod Mount" By Bruce S. Levison Sport Rocketry, 42 (1999), 20

"Ablative Blast Deflectors," By Bruce S. Levison Sport Rocketry, 42 (1999), 30.

"Swivel Device for Painting Model Rockets," By Bruce S. Levison Sport Rocketry, 44 (2001), 35.

“Simulating the Effects of Tube Fins with RockSim” by Bruce S. Levison http://web.archive.org/web/20120219081025/http://www.apogeerockets.com/simulating_tube_fins.asp

“Predicting where your rocket will land using RockSim v4.0” by Bruce S. Levison, Apogee’s Peak of Flight Newsletter, Issue #024, 10/15/00 https://www.apogeerockets.com/education/downloads/Newsletter24.pdf

“Simulating Ring Tail Fins in RockSim v4.0” by Bruce S. Levison, Apogee’s Peak of Flight Newsletter, Issue #027, 11/05/00 https://www.apogeerockets.com/education/downloads/Newsletter27.pdf

“Simulating fins-on-fins in RockSim” by Bruce S. Levison, Apogee’s Peak of Flight Newsletter, Issue #113, 10/27/03 https://www.apogeerockets.com/education/downloads/Newsletter113.pdf

“Simulating Pop-Pod Boost Gliders In RockSim v7 #1” by Bruce S. Levison, Apogee’s Peak of Flight Newsletter, Issue #116, 12/05/03 https://www.apogeerockets.com/education/downloads/Newsletter116.pdf

“Simulating Pop-Pod Boost Gliders In RockSim v7 #2” by Bruce S. Levison, Apogee’s Peak of Flight Newsletter, Issue #117, 12/19/03 https://www.apogeerockets.com/education/downloads/Newsletter117.pdf

“Simulation of Side Pods in RockSim v7.0” by Bruce S. Levison, Apogee’s Peak of Flight Newsletter, Issue #119, 01/27/04 https://www.apogeerockets.com/education/downloads/Newsletter119.pdf

“Simulating Foam-filled parts in RockSim” by Bruce S. Levison, Apogee’s Peak of Flight Newsletter, Issue #122, 03/26/04 https://www.apogeerockets.com/education/downloads/Newsletter122.pdf

”CP's of Short and Fat Rockets in RockSim” by Bruce S. Levison, Apogee’s Peak of Flight Newsletter, Issue #154, 12/30/05 https://www.apogeerockets.com/education/downloads/Newsletter154.pdf

”Creating Short/Fat Rockets in RockSim, Pt. 2” by Bruce S. Levison, Apogee’s Peak of Flight Newsletter, Issue #158, 03/14/06 https://www.apogeerockets.com/education/downloads/Newsletter158.pdf

”Simulating UFO and Cube Rockets in RockSim” by Bruce S. Levison, Apogee’s Peak of Flight Newsletter, Issue #162, 06/15/06 https://www.apogeerockets.com/education/downloads/Newsletter162.pdf

“Advanced RockSim Technique: How to create a nested boat tail in a 2-stage rocket” by Bruce S. Levison, Apogee’s Peak of Flight Newsletter, Issue #172, 12/07/06 https://www.apogeerockets.com/education/downloads/Newsletter172.pdf

“Simulating Angular Airframe Tubes in RockSim v9 - Part 1” by Bruce S. Levison, Apogee’s Peak of Flight Newsletter,Issue #296, 09/27/11 https://www.apogeerockets.com/education/downloads/Newsletter296.pdf

“Simulating Angular Airframe Tubes in RockSim v9 - Part 2” by Bruce S. Levison, Apogee’s Peak of Flight Newsletter, Issue #297, 10/11/11 https://www.apogeerockets.com/education/downloads/Newsletter297.pdf

"3D Printing Nosecones with RockSim" By Bruce Levison, Apogee Components' Peak of Flight Newsletter, Issue #476, 08/21/2018 https://www.apogeerockets.com/education/downloads/Newsletter476.pdf

Other articles that I wrote but didn't get credit for:

"Simulating Strap-on Boosters in RockSim 7: Part 1" By Tim Van Milligan Apogee’s Peak of Flight Newsletter,Issue #108, 08/04/03
https://www.apogeerockets.com/education/downloads/Newsletter108.pdf

"Simulating Strap-on Boosters in RockSim 7: Part 2" By Tim Van Milligan Apogee’s Peak of Flight Newsletter,Issue #109, 08/22/03
https://www.apogeerockets.com/education/downloads/Newsletter109.pdf

"Simulating Strap-on Boosters in RockSim 7: Part 3" By Tim Van Milligan Apogee’s Peak of Flight Newsletter,Issue #110, 09/12/03
https://www.apogeerockets.com/education/downloads/Newsletter110.pdf

"Simulating Strap-on Boosters in RockSim 7: Part 4" By Tim Van Milligan Apogee’s Peak of Flight Newsletter,Issue #111, 09/30/03
https://www.apogeerockets.com/education/downloads/Newsletter111.pdf

[K'Tesh]

You might also find Bruce Levison on this forum to help you with your RockSim simulations. I am the #1 Certified Expert RockSim user, a title and avatar given to me several years ago by Tim Van Milligan at Apogee Rockets. Since I am "certified", I guess I belong in the RockSim Asylum.

Nice!

While not recognized by Tim, and not using RocSim, I've done stuff for Binder Design, eRockets/Semroc, and Aerotech/Quest.

Here's a sample that I'm especially proud of... Mike Fisher's Prototype of the Binder Design Velociraptor:

https://farm8.staticflickr.com/7437/27871674571_99bb3903f3_o.png (https://flic.kr/p/JsVBPi)

Someone on the forums labeled me as the "OpenRocket Chuck Norris". I dig that.

[teflonrocketry1]

K'Tesh,

I have seen your OpenRocket posts on the other forum https://www.rocketryforum.com/threads/kteshs-openrocket-files.123564/, and must say your top notch simulations convinced me to try out the software. While OpenRocket is not yet able to do the complex designs like RockSim (no pods yet), it is much more graphically advanced and can generate the realistic artwork you are well known for. What I appreciate most about OpenRocket is the ability to read files from and convert files into the RockSim format.

[teflonrocketry1]

My latest RockSim article https://www.apogeerockets.com/education/downloads/Newsletter476.pdf
gives details on how to 3D print model rocket parts from the RockSim software without having to learn a CAD program.