Estes Super Neon XL Repair - Stability Question

Good Evening Everyone,

I had a CATO damage my Estes Super Neon XL. I had to remove a section of the body tube and replace the motor mount. I also removed the small balsa fins from the tube fins.



I decided to try my hand at Open Rocket and check the stability of my new creation.

Here is what I came up with:



The stability with no motor is 2 calibers.

With an E9, the stability is 0.951 calibers.

Here is the .ork file if you would like to take a look at what I did:

View attachment Estes_Super Neon XL_CATO Repair_8.14.16.ork

My question is this...can I fly the rocket as is on an E9-6 and expect a stable flight, or do I need to add some nose weight.

Adding nose weight in the simulation does not seem to have much effect on the stability.

The total mass with the motor is 261g. I do not want to add weight if it is not necessary or if it is of little benefit.

This is my first repair and my first attempt at Open Rocket, so I may be way off base here.

Suggestions and advice welcomed!

(I hope this is posted in the correct category)

As long as the 6 second delay isn't too short or long, I think you'll be just fine launching with that stability margin. Close enough to 1 for me. And remember, as the propellant is being burned, the stability margin increases.

You have the CG locked in that file. Adding nose weight will not change anything until the CG is unlocked.

Your Center of Pressure is probably too far forward. Sims have trouble with tube fins.

6 seconds is fine for the "original" rocket. Blows just past apogee by about 20 feet. You might be spot on for the delay without the fin and extra tubing weight.

Thanks for all the helpful advice guys.

I am going to unlock the CG and play with simulation some more.

I found some Open Rocket tutorials and blog posts that have shed some light on corrections I need to make.

At least now I feel more comfortable that my rocket should be stable enough to safely fly.