Any Problems with the Rockethead Rockets RHR 2003 unstable?

[rocket trike]

Hello

We had a customer tha just said he had a problem with the RHR 2003 going unstable with a C6-5. We are not trying to say that this customer is wrong but I am trying to find out if anyone else had a problem with the RHR 2003 with a C6-5. If there is a problem I will have to look at some cahnges for this rocket. I have flown over 30 flights between 2 RHR 2003 on C6-5 and the only problem I had was that the first one ended up in a tree. Please give any information that you can so we can get the problem fixed if there is one.

Thank you
Tom

 

[teflonrocketry1]

Tom,

In lieu of this report, I did some investigating using the RockSim file Bob Cox created for RHR 2003 and posted to the EMRR site. If the parachute was packed so it is just above the motor in the smaller diameter body tube, the stability margin will decrease to 0.7 calibers. If the larger central RHR fins were installed forward of their suggested loaction, or one was missaligned, warped or improperly airfoiled you might get an unstable flight especially in high wind conditions. The loaction of the larger central fins is crucial, placing them at the forward end of the middle diameter tube (when they should be 0.25 inches from the tube's base) will give an unstable configuration.

Hope this helps,

Bruce S. Levison, NAR #69055