OpenRocket altitude problem

I've got two nearly identical rockets designed in OpenRocket, one was the initial design and the second is a cleaned up model to give to my TAPS for approval and the altitude on the second rocket is lower than the first despite having the same outer dimensions, same nose cone, same fins, same motor, and is lighter. How is this possible.

Initial Design


Cleaned up Design


They both have the same simulation settings


The only difference I can see is the original design was made in version 13 where the new one was made in version 14.

A rocket with less mass does not always go higher than a rocket with more mass. Lighter rockets are more affected by drag once the motor is out of boost phase, so they slow down faster and won't reach the same coast height. Conversely the heavier rocket will maintain speed and could coast to a higher altitude in the same time.

kj

qquake2k said:

What about parameters like type of paint and fins rounded or square?

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Thank you, it was the fin thickness, on the old design I left it at the default and the new one put the correct thickness. They now agree

CyborgTable said:

Thank you, it was the fin thickness, on the old design I left it at the default and the new one put the correct thickness. They now agree

Click to expand...

I'm glad you found the problem so easily.