# Open Rocket vs RockSim

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#### scsager

##### Slightly burned-out old guy
Here's my :2:

I used the trial version of Rocksim 9 until it expired. Many have commented on the "parts database" issue. To my way of thinking, this is really just a convenience feature in Rocksim.

I'm not sure if my RS9 trial version had an accurate "parts database" or if it was intended primarily as a feature demonstration of the fully licensed version. I found when selecting "parts" from the database, they did NOT match up favorably with the actual part I had in my hand. I measured the actual parts with a caliper, micrometer, and a gram scale. Sadly they did not match the RS database in many cases. I was disappointed with the finished design in the RS9 demo when it differed in weight and size from the actual rocket I built. Granted the difference was a small one, but still...

As manufactures such as Balsa Machining Service and Semroc, etc. change or add to their catalog of parts for sale, Is anyone maintaining/releasing updates for the database in RS?

If OR did include a "parts database", It might only be good, accurate, useful if the data is accurately maintained.

I might be in the minority, but I like that OR forces me to enter the tube sizes and dimensions. It might not be the easiest or quickest way to sim your rocket, but the way I see it, the end result is as accurate as you are willing to make it.

#### jpummil

##### Well-Known Member
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I might be in the minority, but I like that OR forces me to enter the tube sizes and dimensions. It might not be the easiest or quickest way to sim your rocket, but the way I see it, the end result is as accurate as you are willing to make it.
THIS! The little extra effort seems to really ensure pretty accurate weights and distributions due to having to manually enter dimensions and select proper materials. I'd probably do it this way even if there were a component database included

#### JMGrant

##### New Member
Apogee has a TARC video section on their site that explains how to have separate components come down under their own recovery devices.
Well, don't I feel stupid. After finding the video, I went and tried the technique in OR, only to find that it didn't work.

Thanks, Pat_B, hopefully we'll see this feature pop up in OR, in the mean time, I guess it's worth upgrading my copy of RS.

#### jpummil

##### Well-Known Member
......

......

I might be in the minority, but I like that OR forces me to enter the tube sizes and dimensions. It might not be the easiest or quickest way to sim your rocket, but the way I see it, the end result is as accurate as you are willing to make it.
THIS! The little extra effort seems to really ensure pretty accurate weights and distributions due to having to manually enter dimensions and select proper materials. I'd probably do it this way even if there were a component database included

#### Sampo

##### Well-Known Member
Hi,

Specifically, I want a single stage, single Estes style motor rocket to launch, then separate at ejection into a payload section and "booster" section that return independent of each other.

The payload would use a parachute, while the booster uses a streamer.
To get the parts to separate they need to be as separate stages. The upper stage just wouldn't have any motors.

I just added support for deploying a recovery device when the lower stage separates. If you're in a hurry you can build the code from source, or I can send you a pre-release build. (In older versions you can emulate this by creating a thrust curve with 0.01s burn time and add that to the upper stage - this will cause the recovery device to deploy immediately.)

Unfortunately OR does not yet support simulating descent of lower stages. The code architecture is designed to support this, but it hasn't been implemented.

As for preset components, Kevin Ruland is in the process of adding support for them.

Regards,
Sampo N.

#### JeromeK99

##### Well-Known Member
I found this thread because I wanted to learn a little more about Open Rocket. Haven't learned much that much more than I have discovered on my own.

I'm a long time RockSim user (9yrs) and rocketeer (30+ years). What strikes me as almost absurdly funny is folks complaining about the price of RS. Let's see.... we have a hobby where the bulk of model rocket kits (Estes) are at least $20 on average, mid to high power can be on average around$100. We literally burn money every time we launch from $3 for a C motor to$20+ for an AT G or larger... Even 9 years ago when I was on a tight budget, the $100 for RS was a no brainer. The thing has paid for itself numerous times over. The support is there.. I have been a very happy customer. Now that said... I'm not a big Open Source fan. The whole digital hippie, free the code thing isn't my thing. I've been playing around with OR... built a couple of sims.. imported a bunch of my RS .rkt files... most basic types work... some don't. Being a Rocksim user makes the interface easy to use. I would definitely recommend OR to kids that don't have a lot of money or jobs... and to those on a real tight budget. Honestly though.. if you have a Level 1, 2 or 3 in your sig and complain about$100.. that's just kind of funny.

In all honesty, I'll be using both.. back and forth..

Cheers!

Jerome

##### Well-Known Member
Digital Hippie? Are you suggesting that people that write open source software are lefties? communists? anti-capitalists? Nothing could be further from the truth. I think you're mistaking open source with the Free Software Foundation, which tends to be an ideological driven social movement. They have things in common, but are also very different.

I've owned Rocksim for many years, but I've also contributed several features to OpenRocket as well. I've found Rocksim useful, but at the same time very buggy and maddening to use at times. On the flip side, OpenRocket is still missing a few capabilities that Rocksim has (although the same can be said of Rocksim with respect to OR), but when people have issues the major contributors to OR are very responsive and quick to fix defects.

You're not a fan of open source, yet you confess to continue to use it? Send Sampo a donation for $100 to ease your conscience. Cheers, Doug #### JeromeK99 ##### Well-Known Member Digital Hippie? Are you suggesting that people that write open source software are lefties? communists? anti-capitalists? Nothing could be further from the truth. I think you're mistaking open source with the Free Software Foundation, which tends to be an ideological driven social movement. They have things in common, but are also very different. I've owned Rocksim for many years, but I've also contributed several features to OpenRocket as well. I've found Rocksim useful, but at the same time very buggy and maddening to use at times. On the flip side, OpenRocket is still missing a few capabilities that Rocksim has (although the same can be said of Rocksim with respect to OR), but when people have issues the major contributors to OR are very responsive and quick to fix defects. You're not a fan of open source, yet you confess to continue to use it? Send Sampo a donation for$100 to ease your conscience.

Cheers,
Doug
I like my software to work... Most open source software tends to be in a perpetual testing phase... Most commercial software has been through that for the most part and is only successful if it works! I don't mind buying software.

You say I "confess" to use OR like I have sinned. Isn't that what people that create open-source software want?

As a matter-of-fact I have in the past donated to creators of "free" software if I find them useful. At this point I have not yet found OR more useful than RS... That doesn't mean I won't change my mind at some point..

My conscience is clear. I'm sure Sampo and many others have put a lot of effort into creating a "free" version of this commercially available product. All the calculations and coding I'm sure were quite challenging. My hats off to those involved.

Jerome

#### CarVac

##### Well-Known Member
I like my software to work... Most open source software tends to be in a perpetual testing phase... Most commercial software has been through that for the most part and is only successful if it works! I don't mind buying software.

You say I "confess" to use OR like I have sinned. Isn't that what people that create open-source software want?

As a matter-of-fact I have in the past donated to creators of "free" software if I find them useful. At this point I have not yet found OR more useful than RS... That doesn't mean I won't change my mind at some point..

My conscience is clear. I'm sure Sampo and many others have put a lot of effort into creating a "free" version of this commercially available product. All the calculations and coding I'm sure were quite challenging. My hats off to those involved.

Jerome
"Most open-source software" is a generalization. There is a lot of stable open-source software out there.

And on the other hand, when you say "perpetual testing phase" I like to think of it as "perpetual improvement phase". There's nothing like getting the next best thing. Also, the ability to contribute work, rather than money, to a project is awesome.

#### Derek

##### Well-Known Member
I'm not a big Open Source fan. The whole digital hippie, free the code thing isn't my thing.
you do realize that most of the internet runs on open source sw, right?

#### JeromeK99

##### Well-Known Member
you do realize that most of the internet runs on open source sw, right?
Yes I do! I used email, irc and web in the early 90s. Look at the progress it has made due to the commercialization. None of most of what the web has become would be nearly as advanced if it was not driven by money.....

Now.. back on topic....

#### kruland

##### Well-Known Member
Well, don't I feel stupid. After finding the video, I went and tried the technique in OR, only to find that it didn't work.

Thanks, Pat_B, hopefully we'll see this feature pop up in OR, in the mean time, I guess it's worth upgrading my copy of RS.

JMGrant,

That feature will pop up in the next release.

<edit> When the new release shows up, check out the TARC example. It shows a payload section recovering separately from its booster. </edit>

Kevin

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#### jcantalupo

##### Active Member
I know it's an old thread, but I think at this point the best answer to the original question is this:
Start with OR, and if you get to the point where it can't do what you need, consider Rocksim. OR is free, and it can read/save files in Rocksim format. I use it a lot - it is easy to use, not at all buggy, and now does have a parts database. Nothing to lose.

I'd love to see tube fins and pods in OR as well, but get along without them. Side question: Does either product support tubes cut at a diagonal?

Commercial product or open source? Either one could effectively EOL any time. That's what happens with software. But the flexibility in file formats provided by OR mitigate that to some extent.

And I'll comment: I'm a regular customer of Apogee - great customer service and outstanding amount of free info on their website - but it is worth noting how present and responsive Sampo and other OR folks have been on this thread.

#### Alby

##### Well-Known Member
I know it's an old thread, but I think at this point the best answer to the original question is this:
Start with OR, and if you get to the point where it can't do what you need, consider Rocksim. OR is free, and it can read/save files in Rocksim format. I use it a lot - it is easy to use, not at all buggy, and now does have a parts database. Nothing to lose.

I'd love to see tube fins and pods in OR as well, but get along without them. Side question: Does either product support tubes cut at a diagonal?

Commercial product or open source? Either one could effectively EOL any time. That's what happens with software. But the flexibility in file formats provided by OR mitigate that to some extent.

And I'll comment: I'm a regular customer of Apogee - great customer service and outstanding amount of free info on their website - but it is worth noting how present and responsive Sampo and other OR folks have been on this thread.

OR Rulez...

#### Rktman

##### Eric
TRF Supporter
Does anyone know if OpenRocket can design gliders?

#### BBB

##### New Member
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: https://openrocket.sourceforge.net

I am just getting back into the model rocketry hobby after a few decades of working too much. I too was wondering if Rocsim had any real advantages over the current version of OpenRocket (15.03). OpenRocket seems to have all the motors I would use so that is not an issue. From the pictures on the Rocsim web page it looks like it can do assymetric rockets, like a Bomarc or boost glider, while OpenRocket is limited to models with rotational symmetry. Has anyone out there done an assymmetric model in either program and how difficult was it to do?