ANNOUNCEMENT: The OpenRocket 22.02 Beta Period is now finished

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I'm a bit confused (nothing new...) about the Cg override for the sustainer in the RC release. I am near to finishing up a rocket and I measured the Cg, which didn't quite agree with the calculated value, undoubtedly because of glue, uneven application of paint, etc. So I override the Cg, and click on "override for all subcomponents". So far, so good. However, if I change a subcomponent, it moves the Cg. I would have assumed that the figure entered for the override would take precedence, especially if I am overriding the subcomponents.

Hans.
Hmmm... please post the .ork file and give a very specific description of exactly how you performed those steps.
 
OK. Might be a little while until I get back to the computer with the files on it.

Hans.
False alarm. Chalk it up to user error.

If I select "No motors" in the main rocket display screen, the Cg overrides work as expected. I was a bit puzzled as to why the overrides seemed to not work when, after a motor was selected (causing an expected change), the Cg would move when I changed the mass of an internal component But on reflection, this is how it should be. In effect, the "overrides" are for an empty rocket, and the motor selection overrides the overrides, if you get my drift. That part I understood. But subsequent changes internally also alter the weight imbalance that the motor caused. That's the part I finally realized. Glad you thought this through - better than I would have - when you designed the system.

The way you have it working is handy if the rocket is marginally stable, and nose weight might need to be added for heavier motors. After setting the overrides, one can subsequently tinker with motors and nose weights without having to reset those overrides.

All of the above is worded terribly, I hope you get what I was trying to say....

Hans,
 
I watched my first tutorial on YouTube tonight but it looks like I need to watch all of the others that are on YouTube, multiple times.
 
Just open up the “Simple Model Rocket” example design (File -> Open Example -> A Simple Model Rocket) and explore. 90% of what you need to know is there.

Ask questions here when you have them.

As an experienced rocketeer you should *not* need to watch 1000 hours of YouTube videos to know how to use the program.
 
Catch @JoePfeiffer talking OpenRocket on the latest episode of The Rocketry Show Podcast!

I came here to post a link to that excellent interview, but someone beat me to it.

So, I'll ask a question instead: I haven't checked with the latest release, but even though the program can predict rocket RPM caused by fin cant, my simulation tests seem to indicate that the increase in rocket stability due to spin doesn't seem to be taken into consideration. Is this correct? If so, not really a complaint, just curious.
 
I absolutely love the new Beta and cannot wait for the RC.

I'm running RC1. I haven't had much time to play yet, but I like it... a lot.
(I downloaded, but skipped beta 5)

As soon as I finish getting Linux Mint (thanks for the suggestion @neil_w ) setup on my "new" OLD (like really old) Latitude D830 dual-boot laptop, I will install it there and really beat on it to see what it'll do. :D Can't get wireless working on Mint yet.

Pretty fired up to have a laptop, any laptop, available again.
 
I came here to post a link to that excellent interview, but someone beat me to it.

So, I'll ask a question instead: I haven't checked with the latest release, but even though the program can predict rocket RPM caused by fin cant, my simulation tests seem to indicate that the increase in rocket stability due to spin doesn't seem to be taken into consideration. Is this correct? If so, not really a complaint, just curious.
It doesn't. Something to add somewhere down the road...
 
Thinking about contributing to the documentation side of things. Can't. To whom do I speak about OR Wiki's apparent hatred of my IP address?
My IP is clean. ALWAYS is.

View attachment 560719
For reasons that escape me completely, it sometimes gives me the same error. So far, clearing my cookies for the site has brought it back.
 
Maybe borrow SpinSim code found in FinSim as discussed in Apogee Peak of Flight #90.

https://www.aerorocket.com/
That would only be possible if the author were to make it available under the GPL, which I regard as unlikely (search for his name on this forum to see the reasons for my pessimism).
 
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New problem... OR is not displaying changes to the graphics... I've created a basic image (body tube paint and decals.png)... Then click edit, I make the changes needed to the image, then save it, and yet OR isn't displaying the changes. I have to change the name, and open that new file to get it to work. 15.03 still works, but copying from it, and pasting in the beta doesn't work.
 
A tiny bug that's reproducible consistently for me, any rocket design. If I pick a parachute out of the parts library, save, and re-open the next day (doesn't always work immediately) the parachute will be at max allowed "packed length". Fixing and resaving the issue happens again in another day. Can post an affected ORK file if it helps.
 
A tiny bug that's reproducible consistently for me, any rocket design. If I pick a parachute out of the parts library, save, and re-open the next day (doesn't always work immediately) the parachute will be at max allowed "packed length". Fixing and resaving the issue happens again in another day. Can post an affected ORK file if it helps.
That issue has been fixed after the 22.02.beta.05 release. The fix will thus be included in the final 22.02 version (releasing somewhere this month).
 
That would only be possible if the author were to make it available under the GPL, which I regard as unlikely (search for his name on this forum to see the reasons for my pessimism).
The MathCAD formulas for spin stabilization effects are on page 5 of a PDF document I have in my spin stabilization subdirectory. I don't know where I got it and searches don't turn it up. The file download date is November of 2017.

ROCKET SPIN STABILIZATION USING CANTED FINS
FINSIM ANALYSIS
October 2002
BY JOHN CIPOLLA AEROROCKET
 
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