Is roc-sim really worth getting?

[The Rocket Kid]

I've heard all about this program called roc-sim and i wanted to know if it was something that is really as cool as i've heard.

[chadrog]

It's a very useful tool, if you have a use for it. I use it from time to time, not so much to design but to check my designs. They do offer a free one month trial, you should get that then decide for yourself.

[gwolski]

RockSim is a really nice tool. I also really like OpenRocket and RASAero. Awesome value for the price!

[Benbug]

I highly recommend RockSim. If nothing else, it allows you to visualize your rocket completely before you start building. You can order just the right amount of materials/ components etc.

I use it almost every day - great value for money.

[Aksrockets]

I would try both openrocket and rocksim. If youthink rocksim really has a $90 advantage over openrocket, get it!

Alex

[JStarStar]

I had full-version RockSim a few years ago and it was cool, but quite pricey. If I designed a lot of rockets or a lot of complex ones, I would definitely upgrade to the current version.

These days I use OpenRocket much more -- most of the stuff I design is not tremendously complex so for most purposes it is OK. RS is definitely superior, as it should be in light of price. It has some nice features OR does not.

[blackjack2564]

NO.

Use Openrocket.... it's free. It will also save files in RS.

Should you happen to outgrow it, [which I doubt] then consider buying RS.

[CarVac]

The advantage of RockSim is that it can simulate more complicated designs. However, its simulation of typical rockets isn't known to be the most accurate.
RASAero is limited to 3 or 4FNC, with maybe a fincan and tailcone, strongly limiting its usefulness, but it is extremely accurate up to the very highest-performing flights. It is not a design tool, it is purely a simulation tool that takes in parameters of a rocket's exterior.
OpenRocket is a design tool, like RockSim, but it has slightly less capabilities: it can't have external pods or tube fins. However, its aerodynamics are better in the high-speed regime than RockSim.

I don't own RockSim, but my school does. I used it to design and simulate a cluster rocket with pods (not yet built), but otherwise I use OpenRocket to design and RASAero to simulate.

[rockets4kids]

If you are designing a "traditional" rocket, OpenRocket and RASAero will likely do all you need. RASAero is preferred over OpenRocket if you are going to go supersonic. RockSim has lots of bells and whistles and can model non-traditional designs, so if you need those features then it is well worth the price.

[Salvage-1]

I have RockSim and OpenRocket on this computer. I seem to do most of the designs in RockSim, and then open then up in OpenRocket to check data between the two, ie, altitude, etc.

Both are useful, but, OpenRocket is the one to get if you dont have the cash for RockSim!

[FastCargo]

And OR will run on an Android tablet and phones. Perfect for when you are at the field.

Next iteration of OR for Android will allow for engine configuration changes in simulation.

FC

[FastCargo]

Okay, I feel silly. Apparently, there has been a beta version of OR out since April that gives you the ability for this:



Who knew...

FC

[CarVac]

Those tubes at the wingtips are modeled as inner tubes, which do not appear at all in the aerodynamic calculations. You can feel free to design things with them outside the rocket, but it won't simulate.

[FastCargo]

I am aware of that...though the sim does take the weight of the tubes into consideration.

FC

[MarkII]

I've heard all about this program called roc-sim and i wanted to know if it was something that is really as cool as i've heard.

Yes. Absolutely. It is packed with useful features, is very well-supported by the vendor and has a huge knowledge base associated with it. It is the de facto standard for simulation software in the hobby.

[MCS]

I have to question the accuracy of any model with an odd shaped rocket.

I am a big fan of OpenRocket and OR has a lot of nifty features in the pipeline.

[cavecentral]

Never used it. I'd imagine it (or a similar app) is important for high altitude attempts (for an estimate). Anything where the motor is so big that you need to know how much to weight the nose cone to be stable. I'm sure it is great for L3 attempts to know your exact CG as well. Alos for motor ejection if you have no idea what delay reange is proper for a rocket.

[MCS]

The real problem for high altitude is the FAA Class 3 license... begining with 6DOF simulations. I haven't seen an alternative to ($1,000) RockSimPro.

On my wishList/todoList is to look into adding the feature to OpenRocket, but it is only a fantasy for now.

[Adrian A]

Yes. Absolutely. It is packed with useful features,

True

is very well-supported by the vendor

Depends if a failure to fix bugs that were pointed out 2+ revs ago counts as not-well-supported

and has a huge knowledge base associated with it.

True

It is the de facto standard for simulation software in the hobby.

Definitely not true for supersonic flights due to serious drag accuracy problems that have been well-known for a long time. RASAero is the standard there.

[daveyfire]

Depends if a failure to fix bugs that were pointed out 2+ revs ago counts as not-well-supported.

+1!

[G_T]

I use Rocksim as a CAD program to lay the rocket out. Then I plug in real measured masses (when I have them) as the defaults are not all that accurate. I include chutes, electronics, Kevlar, quick links, everything. That gets me a decently accurate expected final mass and CG. Then I take this and use RasAero for analysis. I find the combination works well for me.

I have very little experience with Open Rocket. I have imported some of my stuff out of curiosity. It looks like it would probably be better to not do the import but to redesign.

If all you want to do is slap some tubes together with fins that are too big, then really you don't have a need for these programs. If you have a target stability range, they help. If you plan to go fast, they help. If you plan on a complex rocket, they help. If you have a need to determine if you might be closing in on a waiver, RasAero helps. If you are subsonic, and have real measured masses, Rocksim seems decently accurate and I'd expect Open Rocket is as well.

It really depends on what you want to do. If you just want to make some rockets to fly, then you don't need any of this. If you want to design for specific behavior, then it helps to have some tools to aid in the process. These tools are not hard to use, but there still is a learning curve.

0.02c

http://www.rocketryforum.com/showthr...t-and-a-baby-O

You can look at the pictures in the first post of that thread to get an idea of the sort of thing you can do with Rocksim or Open Rocket. The pictures seem to have been mangled by compression during import. I'll likely have to replace them. Many lines disappeared... But it should still give you an idea. Subassemblies are in different colors. Yep, I could have designed that rocket without software support. But I could do it better and/or faster with the software.

Gerald

[PhlAsh]

If you do upscaling and downscaling, you can load the traditional rocket's file, set the multiplier then tweek the individual parts. Once done, you can produce a shopping list, sim different motors and different range/weather conditions. You can predict optimum delay times for delay-drilling. All sorts of stuff can be done with RockSim that OR just isn't up to (yet)

[CarVac]

OR can sim W and weather conditions, as well as predict optimum delay times.

[FastCargo]

If you do upscaling and downscaling, you can load the traditional rocket's file, set the multiplier then tweek the individual parts. Once done, you can produce a shopping list, sim different motors and different range/weather conditions. You can predict optimum delay times for delay-drilling.

OR can do all of this, and can do some of it on your Android phone...

FC

[PhlAsh]

OR can do all of this, and can do some of it on your Android phone...

FC

I stand corrected...