Rediscovering RASP

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Buckeye

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Since it has been a few years, I dug up the venerable RASP program from www.rocketryfiles.com. I installed the wRASP32 version on my 64-bit Win7 machine (after a few installation complaints about out of date .dll files and such), and it seems to be working fine.

I love the simplicity. Inputs: rocket mass, diameter, Cd, motor, and basic environment conditions. No “building” a rocket needed. All the simulation results are neatly placed on one window when you click “Launch.” Included are max values, delays, graphs – everything I need.

Nice features include helpful warnings, various Optimal Mass scenarios, a “Good Motor” filter (somebody was asking for this in OR in another thread), and the ability to input your own Cd vs. Mach curve.

Anyway, an oldie but still a goodie for quick flight simulations.
 
Yep, I still use this. And its older counterpart, pRASP (for the PalmOS!). I wish there was a simple RASP like this for the MAC.
 
It would be great if it could be ported over to our phones. I'm no programer so I don't know if thats possible.


Richard
 
An alternative phone friendly entry screen for Motor Guide would be really useful. I am often asked to give a sanity check on max altitude, delay times, etc. What is easy to do at home on real computer is much more difficult in the field with the screen size and data entry difficulties on small mobile devices.
 
Since it has been a few years, I dug up the venerable RASP program from www.rocketryfiles.com. I installed the wRASP32 version on my 64-bit Win7 machine (after a few installation complaints about out of date .dll files and such), and it seems to be working fine.

I love the simplicity. Inputs: rocket mass, diameter, Cd, motor, and basic environment conditions. No “building” a rocket needed. All the simulation results are neatly placed on one window when you click “Launch.” Included are max values, delays, graphs – everything I need.

Nice features include helpful warnings, various Optimal Mass scenarios, a “Good Motor” filter (somebody was asking for this in OR in another thread), and the ability to input your own Cd vs. Mach curve.

Anyway, an oldie but still a goodie for quick flight simulations.

Did you have to do anything especially complex? I'm from the if-it-doesn't-work-right-delete-it school of computers. I used WRASP and vcp 1.64 until neither would work anymore with the OS "updates".

I get RASP working and get ahold of Gary (writer of vcp) and see if there's a fairly easy way to get vcp working and I'm gold. I'm working with SpaceCAD. It's ok but....
 
Did you have to do anything especially complex? I'm from the if-it-doesn't-work-right-delete-it school of computers. I used WRASP and vcp 1.64 until neither would work anymore with the OS "updates".
I have the wRASP32 version running on Win 8.1 and I didn't do anything special except just do the install.

All the files I had saved worked fine with it.
 
wRASP32 packages some Windows libraries. During install, your computer will tell you that you already have newer versions of these files. Keep the newer versions and proceed with the install.

wRASP32 uses the old Windows Help format. If you want the Help documentation (it is good), then there is a Windows Update that you need to do. You will be directed to it when you try to launch the Help menu from wRASP32. It is easy.
 
wRASP32 is always my first choice when I need a quick sim. I changed the Motor Data under Settings to MyMotors.eng file which I created and update with all the new .eng motor profiles. If it doesn't have the motor I want, I just use a text editor to copy of the .eng file data to the MyMotors.eng file.

One issue I did come across when I first started trying to load CTI .eng files is that wRASP32 will only allow 6 delay times. As soon as you put a 7th delay time in the data for a motor, you get a subscript out of range error when you try to open the program and it tries to read the file. The first CTI .eng files I tried would list every second of adjustable delay for a motor i.e. 5-6-7-8-9-10-11-12-13-14. I think the .eng files from ThrustCurve only use 5 or fewer delay times for CTI motors now , but if you get an old .eng file or one from another source, it might be an issue.
 
That is not true of Thrustcurve as far as I know, and I am the Editor of Thrustcurve. The older rasp had some limitations compared to newer simulators. I am not arguing that it does not work, but you may need to edit the files a little to take out the extra delay times.


Mark Koelsch
Sent from my iPhone using Rocketry Forum
 
That is not true of Thrustcurve as far as I know, and I am the Editor of Thrustcurve. The older rasp had some limitations compared to newer simulators. I am not arguing that it does not work, but you may need to edit the files a little to take out the extra delay times.


Mark Koelsch
Sent from my iPhone using Rocketry Forum
I had to edit out the extra delay times when I recently updated my .eng files because of the subscript error. I believe I got them from Thrustcurve
 
The other limitation of wRASP that isn't enforced by ThrustCurve.org is 31 point maximum (32 including the final zero). While few files have more points than that, it's something to look out for.
 
An alternative phone friendly entry screen for Motor Guide would be really useful. I am often asked to give a sanity check on max altitude, delay times, etc. What is easy to do at home on real computer is much more difficult in the field with the screen size and data entry difficulties on small mobile devices.
That's a great idea; let me think about what it would take to do. (I don't have any experience writing mobile apps, but I could probably whip something together with PhoneGap without too much difficulty.)

I don't want to infringe on the territory of the dedicated simulators, but I've always been puzzled why they don't get the latest data automatically and why they don't provide a "try every motor" feature.
 
I don't want to infringe on the territory of the dedicated simulators, but I've always been puzzled why they don't get the latest data automatically and why they don't provide a "try every motor" feature.

Because sometimes you design a rocket for a specific motor. And you want to know what the stability looks like throughout the flight.
 
I don't want to infringe on the territory of the dedicated simulators, but I've always been puzzled why they don't get the latest data automatically and why they don't provide a "try every motor" feature.

I love this feature. For my big rocket projects, I want to achieve a certain flight regime, and I want to know which motor will get me there. I am not attached to any motor brand, flame color, or impulse level. The motor is just a disposable, plug and play commodity to me. I pick the motor to fit my airframe design, not vice versa. Given the hundreds (thousands?) of motors available, the MotorGuide-like feature in a simulator is the only way to quickly narrow the choices.
 
I don't want to infringe on the territory of the dedicated simulators, but I've always been puzzled why they don't get the latest data automatically and why they don't provide a "try every motor" feature.
The "try every motor" feature is called the "Good Motor" feature in wRASP32. It will run a quick sim on all motors within a specified size & impulse range, and list all motors that meet a specific flight profile (min/max altitude, min launch speed, max speed/accel, etc.) for the specified rocket. Very handy.

Sure wish I had the source code to wRASP32, I'd like to (attempt) a port to newer desktop OS versions. I'd really like an OSX version of this.
 
I do have a zip file with the wRASP source code (or at least that's what the sub-folder says). I probably got it a few years ago on a website, but I cannot find out where now as I got no hits when I did a search. So I wonder if the website I got it from no longer exists.

Greg
 
I do have a zip file with the wRASP source code (or at least that's what the sub-folder says). I probably got it a few years ago on a website, but I cannot find out where now as I got no hits when I did a search. So I wonder if the website I got it from no longer exists.

Greg
I had this site listed on my webpage https://www.wrasp.com/ but it appears to no longer exist. might try the internet archive (wayback machine) -- it is blocked here at work, so I can't check it out.
 
Sure wish I had the source code to wRASP32, I'd like to (attempt) a port to newer desktop OS versions. I'd really like an OSX version of this.
IIRC, wRASP was written in VisualBasic. But rather than port it to another single platform, I suggest a web app.

Or, use the ThrustCurve.org Motor Guide which already does this.
 
IIRC, wRASP was written in VisualBasic. But rather than port it to another single platform, I suggest a web app.

Or, use the ThrustCurve.org Motor Guide which already does this.
Note that wRASP32, is *not* the same wRASP. Yes, thrustcurve is great, but I often need an offline tool, so use wRASP32, pRASP (palm V), and/or SmartLaunch (iPod).
 
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