Open Rocket Software Question

[VonRecktofen]

Hey Gang,
Just a stupid and probably obvious question for more experienced Rocketeers, but where is the CP measured from in Open Rocket? I presumed that it was from the nosecone, but I'm building an Estes Astron Sprint XL, and the sim file that I found had a nosecone a bit too long, so I adjusted the length shorter in OR and now it puts the CP at 15.67 inches back...The measurement doesn't come close to the diagram on the build window underneath...Is the CP measured from the tip of the component?

Maybe I need to find a more accurate sim file, just trying to learn how to use the software on my own.

Thanks for any information or suggestions!

Franz in NJ

 

[K'Tesh]

Can't answer the computations questions for you... However, I've been known to do a sim or two.

I'd suggest you check out this thread...

https://www.rocketryforum.com/threads/kteshs-openrocket-tutorials.62884/

And you never know, I may have a sim over here that can help...

https://www.rocketryforum.com/threads/kteshs-openrocket-files.123564/#post-1430472

[Edit] D'OH!!! You want this sim...

https://www.rocketryforum.com/threads/kteshs-openrocket-files.123564/page-3#post-1459443



Pointy Side Up!!!

 

[T-Rex]

It measures from the tip of the nose. What was the CP before you changed the nose length?
The CP should have changed basically the amount you changed the nose length (+/-). Are you maybe confusing the CG & CP marking on the diagram?

 

[VonRecktofen]

It measures from the tip of the nose. What was the CP before you changed the nose length?
The CP should have changed basically the amount you changed the nose length (+/-). Are you maybe confusing the CG & CP marking on the diagram?

Thanks Terry,
CP is the Red circle with the dot, correct? I also had to measure and then change the length of the body tube to accurately represent the model that I have and now the CP mark on the software looks closer to where it is measured on the actual rocket...

So much to learn!

Thanks for the information....
Franz in NJ

 

[K'Tesh]

Thanks Terry,
CP is the Red circle with the dot, correct? I also had to measure and then change the length of the body tube to accurately represent the model that I have and now the CP mark on the software looks closer to where it is measured on the actual rocket...

So much to learn!

Thanks for the information....
Franz in NJ

If you look at the top right corner of the build window (where the rocket you are working on, you'll see the blue Secchi Disk that represents the CG, and the measurement of its location, and the red dot in the center of the red circle that gives the CP's location.