OpenRocket 12.03 motor data editing

[Tom M.]

How do you edit the existing motor data files or add new motor data?

Tom M.

[Polyalcoholic]

If you have files from Burnsim or Motorsim:
Edit->Preferences->Options(tab)->user-defined thrust curves
Navigate to the folder where you store your motor data.

To edit an existing file I use Thrust Curve Tool
http://www.thrustgear.com/software.html

[CarVac]

I to this day cannot get OpenRocket to see the new thrust curves I put in, so I can't simulate things with newer motors...

[scsager]

There are two main ways to work with the motor database in OpenRocket.
#1 the easy way.
#2 The perfectionist way.

The easy method is just that - easy.
The perfectionist method is more difficult, but affords much greater control.

To start you should know that OpenRocket has a Built-in motor Database. In addition to the "Built-in" motors, you can tell OpenRocket to use your own collection of motor files.

The easy way.
You can find motor or engine files around the interwebs at places like thrustcurve.org
Motor files are simply files that contain motor data. The file names end in .eng or .rse.

For example, you can surf to thrust curve and search for a particular motor - for example the G138.

Then you can download the motor file to your computer.

It looks like this AeroTech_G138.eng

The trick is - to keep all your motor files in one folder on your computer. I keep all my motor files in a folder called "all my motor files".

This can be any folder anywhere on your computer, as long as you know where it is and can find it.

I got a nice big collection of them that I have gathered over the years.

Now Run OpenRocket.

Click on EDIT
Then Click PREFERENCES
Then Click OPTIONS

Where it says "User defined thrust curves:"
Click the ADD button

Then browse to your collection and click the ADD button.

Open rocket will use the built-in motor database AND the files in your motor folder.

All done - it's just that easy.

[scsager]

But wait - there's more.

I should point out these are PC instructions. If you have a Mac, - you can use these instructions as a GUIDELINE.

#2 The perfectionist way.
If you are a perfectionist like me, you may not be happy with the built-in motors at all. You might want OpenRocket to use ONLY your motor collection and nothing else.

If you seek perfection, then you need a little additional knowledge, and must take some additional steps.

First you should know that OpenRocket is a Java file. When you download it, you get just one file.

The .jar file is actually made up of many files and folders all smooshed into one. Smooshed - that's technical computer-guy talk - don't let it confuse you.

You need a tool to "pop the hood" on the jar file so you can change or delete the built-in motors.

The tool you need is called 7-zip. This is a free tool you can download from 7-zip.org.

After you download and install 7-zip, you are ready to do some work on the .jar file.

Locate the Openrocket .jar file on your computer. Once you have located it, now comes the hard part.

You want to open the .jar file with 7-zip. More specifically with the 7-zip file manager.

Start by RIGHT clicking the jar file.
From the menu choose OPEN WITH…

The 7-zip file manager might not show up as a choice. If that's the case, then click CHOOSE DEFAULT PROGRAM at the bottom of the list.

Important point -> UN check the box that says "ALWAYS USE THIS PROGRAM TO OPEN THIS KIND OF FILE". Then Click the BROWSE button.

Browse to where the 7-zip files are installed.

Choose the file "7zFM.exe" and click OPEN.

Once again make sure to UN check the box that says "ALWAYS USE THIS PROGRAM TO OPEN THIS KIND OF FILE".

Then click OK.

This will open the jar file with 7-zip… and you are now looking "Under the hood" at all the STUFF that makes OpenRocket work.

Now …
Double click "Datafiles" to open that folder.
Then Double click "Thrustcurves" to open that folder.

Now you are looking at all the motor files that are Built-in to OpenRocket.

Now what?

If you are like me, You may have a very good collection of AT, CTI, and Estes motor files of your own.

I simply highlighted all the motors in OpenRocket that I did NOT want… and clicked delete.

You MUST leave at least ONE motor in the Built-in database. Not sure why this is - but if you delete them all it won't work.

At this point, you can simply close 7-zip.

OpenRocket will read any motors still left in the Built-in database AND the motors in your motor folder (as described in the easy way instructions)

One last thing… Open rocket will read motor files in a .zip file too. I have all my Estes motors in one .zip file. OpenRockets reads .eng, .rse, and .zip.

sorry only one screen shot - maybe if I have a ton of free time later in life - I could write up a how-to guide

[CarVac]

Ah. I didn't really feel like putting the effort into opening the jar archive, especially since I double check my sims on RASAero anyway... I use Linux so maybe it just doesn't like reading from a folder.

[Sampo]

Hi,

Also note that if there are duplicate thrust curves defined for the same manufacturer/designation, then they all appear in the motor selection dialog under the same row. Once you select the motor, you can select the specific thrust curve from the dropdown box on the top-right. You might need to untick the "Hide very similar thrust curves" tickbox to see all the curves.

In Linux OpenRocket by default read extra thrust curves from $HOME/.openrocket/ThrustCurves, so you can drop the eng, rse or zip files there as well.

Regards,
Sampo N.

[CarVac]

I was putting them there but they staunchly refused to be read.

[JPVegh]

scsager, thanks for the tutorial, I've been wanting to add the Estes E12 for a while. Followed your instructions last night and had it done in a matter of seconds. Thanks again!

[kruland]

JPVegh,

Do you have "official" files for the Estes E12 motors? I could get them added to the next OpenRocket release.

Kevin

[MCS]

>> I was putting them there but they staunchly refused to be read.

If you have a syntax error in the *.eng file the motor will not show-up. Some tools (HDAS for example) don't build the *.eng file correctly. I have better luck modifying a working file when building custom burn curves.

Also watch the name of the motor vs name of the file. Sometimes the custom motors show-up in strange places in the master list.

-->MCS

[FastCargo]

Quick side note... I'm getting an error trying to open the latest OR PC beta (the one with the 3d view) on Windows 8 32-bit. I know the OS isn't released yet... figured y'all could use the data point. I'll try to get the data dump if you are curious.

Been testing the latest OR betas on the PC and Android... they've been awesome. Haven't found any new issues with either that haven't already been documented. Y'all will find adding motors is even easier on the Android version.

FC

[CarVac]

I basically pulled my RASAero .eng file (which works completely) and dumped it in that directory, but no new motors showed up.

[JPVegh]

JPVegh,

Do you have "official" files for the Estes E12 motors? I could get them added to the next OpenRocket release.

Kevin

Hmmm, that's a good question. The file I used is one that was posted here on the forum in the "New Estes BP Motor - E12" thread.

http://www.rocketryforum.com/showthr...ight=Estes+E12

I have no Idea how "official" it is.

[Tom M.]

Thanks!

[donperry]

Download Free ENG Editor. It was built FOR open rocket, so it exports the ENG file directly in the correct directory.
Link: FREE ENG EDITOR

[MCS]

Thanks for the ENG editor. Nice!!!

One suggestion I can make for improvement is letting the user specify units (lb, oz, kg, etc)