Open Rocket vs RockSim

[Alby]

Can anybody comment on the quality of Open Rocket vs. RockSim?

Considering the cost of RockSim, I'd really like to not purchase the
full version if Open Rocket is just as good. Initially, I've not noticed any
real issues. So I'm wondering, is the RockSim price tag really worth it
if you've got this Open Source alternative called Open Rocket?

The first thing that comes to mind is Windows vs. Linux.

Source: http://openrocket.sourceforge.net

[SteveF]

rock sim does have a free trial period so you can compare them. Open rocket will open rocksim files so you can get the files from rocket reviews. Overall I think you will find open rocket should do what you need

[jms]

There are a few subtle differences that RockSim offers above OpenRocket. For 90% of what you're probably going to do (based on that badboy rocket you have on there) OR is going to do it for you. Also I notice you are in fact using it on Linux, which will save you try to run RockSim under VMWare or WINE.

[Alby]

There are a few subtle differences that RockSim offers above OpenRocket. For 90% of what you're probably going to do (based on that badboy rocket you have on there) OR is going to do it for you. Also I notice you are in fact using it on Linux, which will save you try to run RockSim under VMWare or WINE.

That pic is just a screenshot from SourceForge. But it seems like
Open Rocket is likely the best choice unless you are doing something
super advanced.

[Eric1]

I'm spoiled I use them both, I just started with Open Rocket though.
Very cool features, I'll keep using Rocksim though, I'm pretty quick with it.

I don't think of either as a bad choice.

Eric Foster

[Lentamental]

Does open rocket work on linux? That would be a major plus.

[SteveF]

yes - open rocket is java - you need to install java but it is free and and there is a linux version - so open rocket runs on linux

[jms]

Yeah just as I described in another thread, just fire it up with a "java -jar OpenRocket.jar" on your commandline. I think I had java already but on a Debian/Ubunutu machine just do a "sudo apt-get install sun-java" and you should be ready to rock.

[Lentamental]

Well it was considerably more complicated than that for me, but I got it to work. Thanks for the help!

[gpoehlein]

Well, I tried Open Rocket, but it still has a few kinks to work out.

Aside from the fact that there are to parts databases to choose from (it is really handy to just select a nose cone or body tube in Rocksim), OR does not do tube fins. I tried using the old Rocksim 7 trick of using three fins per tube with the length and cross section of the tube for each fin, but OR tells me I have too many fins - it apparently maxes out at 8 fins. Also, having to create the model with the motor already in it is a little clumsy and counterintuitive, and since there are no instructions, it is a bit of a hurdle. It did a pretty good job of simming a BT-80 Tartar, so I'm gonna keep playing around with it, at least until I can get Rocksim fixed.

[AndyC]

I've been using OpenRocket for a while. I've been quite happy with what it does. My approach was not to expect it to be a drop-in replacement for Rocsim - actually I hope as it continues to develop it moves in different directions, possibly better ones than Rocsim.

I agree, parts databases would be nice, though maybe not necessary for me. I've not had to have a motor in it during a build. I've always built without adding a motor until the end, then you can switch the motor configuration drop down box above the rocket picture on the right from "No Motors" to one of your choice.

[Sampo]

Hi,

Yeah just as I described in another thread, just fire it up with a "java -jar OpenRocket.jar" on your commandline. I think I had java already but on a Debian/Ubunutu machine just do a "sudo apt-get install sun-java" and you should be ready to rock.

Or you could just do "sudo apt-get install openrocket" (or do the same through the graphical software management). Debian has OpenRocket readily packaged, though I haven't tested it. Also you won't have the very latest version unless you're running Debian unstable/testing.

I know having a parts DB would be useful, but since I personally live in Finland and don't really have ready parts available, it hasn't been a high priority for me. I've got some ideas for it though. If someone wants to help out a bit...


Cheers,
Sampo N.
(OpenRocket main developer)

[Lentamental]

Or you could just do "sudo apt-get install openrocket" (or do the same through the graphical software management). Debian has OpenRocket readily packaged, though I haven't tested it. Also you won't have the very latest version unless you're running Debian unstable/testing.

Right now I've just got the .jar on my desktop and made a little launcher applet on my top bar that runs the launch script (I'm on Ubuntu 10.4). I'll let you know how that goes once I get a little free time to mess around with it. I'll mainly be using it on linux on my netbook at school when I don't want to lug my big laptop everywhere.

[jms]

Hi,



Or you could just do "sudo apt-get install openrocket" (or do the same through the graphical software management). Debian has OpenRocket readily packaged, though I haven't tested it. Also you won't have the very latest version unless you're running Debian unstable/testing.

I know having a parts DB would be useful, but since I personally live in Finland and don't really have ready parts available, it hasn't been a high priority for me. I've got some ideas for it though. If someone wants to help out a bit...


Cheers,
Sampo N.
(OpenRocket main developer)

If you handled the GUI madness and just exposed some methods, I would totally be willing to do a MySQL or sqlite (or if you have any other suggestions) database layer for OR. I am by trade a Python guy, and I've really been looking at how I could help out using Python...unfortunately I think I may have to learn java

Didn't realize OR was in the repos either, good tip.

[Alby]

I've not had any issues so far with OpenRocket. I'd have to say,
Free Open Source is likely going to give RockSim a run for its money.

[SacEsq]

Looking at Open Rocket and I like it. Was wondering tho ... is there a way to just select a popular kit and mod from that? Or do you have to put in all of the specs of your kit and then do the mods for a sim?

Thanks

[jpummil]

You can grab Rocksim files of many kits from EMRR's Rocksim Library then read them into Open Rocket for modding.
Just remember, the end result is only as good as the data you use. I prefer to weigh things as I go to make sure the Rocksim files agree with the real stuff

[SacEsq]

You can grab Rocksim files of many kits from EMRR's Rocksim Library then read them into Open Rocket for modding.
Just remember, the end result is only as good as the data you use. I prefer to weigh things as I go to make sure the Rocksim files agree with the real stuff

Thanks

[Alby]

I'm an Open Rocket fan. Open Source baby....

[El Phantasmo]

Things lacking in OpenRocket I have Found:

1. I have yet to find a way to design anything in OpenRocket that allows for tubes to be positioned non-concentrically, but it's still all I use for now. No custom tube fin designs for me.

2. I can't cut open a nosecone to have a smaller nosecone protrude forward to mimic a ramjet.

3. It won't create a custom, colored 3D graphic.

4. No "free form" nosecone design.

If someone can correct me on the first 2, I'd be grateful.

You can install the trial version of RockSim and move/copy all the pre-made rockets to some other folder then use them in OpenRocket. Not all features transfer, like spill holes.

[[POW]Eagle159]

Things lacking in OpenRocket I have Found:

1. I have yet to find a way to design anything in OpenRocket that allows for tubes to be positioned non-concentrically, but it's still all I use for now. No custom tube fin designs for me.

2. I can't cut open a nosecone to have a smaller nosecone protrude forward to mimic a ramjet.

3. It won't create a custom, colored 3D graphic.

4. No "free form" nosecone design.

If someone can correct me on the first 2, I'd be grateful.

You can install the trial version of RockSim and move/copy all the pre-made rockets to some other folder then use them in OpenRocket. Not all features transfer, like spill holes.

Its a simulator remember not Photoshop!!!

I don't think that ramjet nosecones will affect the Cp/Cg more than a normal NC




Foe me now,
I don't use any sims. at all.

[T-Rex]

Keep in mind, Open Rocket is a free product! Sampo is generous enough to allow us to use his work. He could very easily charge us for his product.

Yes there are things that it wont do, like tube fins, or pods, but is sure is nice to have for the basics. One day when I feel the need, I may bite the bullet and purchase a copy of RockSim, but for now I am thankful that OR is out there and free.

Thank you Sampo!

[GDJ]

I don't have an opinion on Rocksim, but I have heard good things about it.

If you learn and work around OR, you can work around any limitations it has, but so far it's been pretty faithful to real life, as long as you plug in all the numbers and don't guess.

OpenRocket will serve you well.

[Dr. Quigley]

Things lacking in OpenRocket I have Found:

1. I have yet to find a way to design anything in OpenRocket that allows for tubes to be positioned non-concentrically, but it's still all I use for now. No custom tube fin designs for me.

2. I can't cut open a nosecone to have a smaller nosecone protrude forward to mimic a ramjet.

3. It won't create a custom, colored 3D graphic.

4. No "free form" nosecone design.

If someone can correct me on the first 2, I'd be grateful.

You can install the trial version of RockSim and move/copy all the pre-made rockets to some other folder then use them in OpenRocket. Not all features transfer, like spill holes.

I can, in fact. To place off-center tube fins, there's a tab in the inner tube editing window with something to do with radial placement. And to fix the nosecone problem, you could use a transition instead, then a nosecone. It'll complain about mismatched diameters, but it'll sim.

[El Phantasmo]

Its a simulator remember not Photoshop!!!

Agreed, OpenRocket is not PhotoShop and neither is RockSim. But, RockSim can do what I mentioned. This thread is titled OpenRocket vs RockSim.

I can, in fact. To place off-center tube fins, there's a tab in the inner tube editing window with something to do with radial placement. And to fix the nosecone problem, you could use a transition instead, then a nosecone. It'll complain about mismatched diameters, but it'll sim.

Thanks. Too bad it still treats the off center tubes as inner tubes.

[dunedain289]

Tube fins are the big missing feature to me as well. I tried researching tube fin simulation methods, hoping to help out, but couldn't find much. Does Barrowman handle them and I missed it? I'm an electrical engineer, not aerospace, so some of the physics gets past me - on the other hand, I usually understand programming .

[jeffgeraci]

I have 9 days left on my free ROCsim trial, and I'm torn whether or not to buy it. I swore i'd never use a computer program for rocketry, but I have to say I learned quite a bit just by fiddling around. At first, I was frustrated that I couldn't even move pieces around (tried to click and drag, which it won't let you do), but after an hour or so, I was running with it with ease.

WHAT I LIKE:
I absolutely LOVE the way you can pick an existing stock part from an actual supplier! (and custom too!) Let's say you want to start with your airframe: you can select a 2.1 quantum frame from PML, and the specs are automatically loaded!! This means you can build an entire rocket, and you already have all the part numbers you need right there! You can just call up and say "hey, I want these parts" It's almost disgusting.

What I don't:
It allows you to lanch a rocket without vital components installed. For example, I made a rocket and forgot the centering rings and launch lug; it allowed it to launch anyway! I guess the program is not designed to indicate when your rocket might end in disaster, but it does give an idea on stability.

I still don't know if I should buy rocsim or another program. I'm leaning toward rocsim, because it was easy to learn.

[gpoehlein]

I have 9 days left on my free ROCsim trial, and I'm torn whether or not to buy it. I swore i'd never use a computer program for rocketry, but I have to say I learned quite a bit just by fiddling around. At first, I was frustrated that I couldn't even move pieces around (tried to click and drag, which it won't let you do), but after an hour or so, I was running with it with ease.

WHAT I LIKE:
I absolutely LOVE the way you can pick an existing stock part from an actual supplier! (and custom too!) Let's say you want to start with your airframe: you can select a 2.1 quantum frame from PML, and the specs are automatically loaded!! This means you can build an entire rocket, and you already have all the part numbers you need right there! You can just call up and say "hey, I want these parts" It's almost disgusting.

What I don't:
It allows you to lanch a rocket without vital components installed. For example, I made a rocket and forgot the centering rings and launch lug; it allowed it to launch anyway! I guess the program is not designed to indicate when your rocket might end in disaster, but it does give an idea on stability.

I still don't know if I should buy rocsim or another program. I'm leaning toward rocsim, because it was easy to learn.

Well, I love Rocsim - I bought version 7 and have purchased both upgrades. I consider it to be very flexible and useful for a lot of purposes. As for allowing you to launch without launch lugs, that isn't an issue if using a tower, so simming without LLs is sometimes preferable. And forgetting the centering rings will mess up the CG calculations, but won't affect the CP - and if you measure the weight and CG of the finished rocket and put that in, any differences between what is inside the real thing and the sim is moot. Open Rocket is just too limited for me, and I really don't like that you have to "build" the rocket with a particular motor, then change the design if you want to try a different motor - having a library of motors for your design in Rocsim so you can compare performance in a single table is a plus for me.

[jpummil]

Well, I love Rocsim - I bought version 7 and have purchased both upgrades. I consider it to be very flexible and useful for a lot of purposes. As for allowing you to launch without launch lugs, that isn't an issue if using a tower, so simming without LLs is sometimes preferable. And forgetting the centering rings will mess up the CG calculations, but won't affect the CP - and if you measure the weight and CG of the finished rocket and put that in, any differences between what is inside the real thing and the sim is moot. Open Rocket is just too limited for me, and I really don't like that you have to "build" the rocket with a particular motor, then change the design if you want to try a different motor - having a library of motors for your design in Rocsim so you can compare performance in a single table is a plus for me.

Change the design to use a different motor?!?! I typically have 3-4 motors per design loaded up to compare. Just go to the "Motor Configuration" pull-down mid page on the right, select "Edit Configurations", then click "New Configurations" as many times as you like. Then, in each configuration, double click where it says "None" in the right column and select one of a plethora of motors from various manufacturers. Load as many as you like here, then you can easily compare back at the main screen by selecting the one you want from the "Motor Configuration" pulldown again.

[jeffgeraci]

I really don't like that you have to "build" the rocket with a particular motor, then change the design if you want to try a different motor.

Thank you, you've made up my mind; I find that I switch motors constantly, and no WAY do I want to have to change the design every time! That's worth $120