Restrictions on 3D printed rockets for cert flights?

[rharshberger]

I don't believe Steve is actively trying to "break the rocket", applying light to moderate pressure to determine if something is loose or can break loose is reasonable, as would be light to moderate flexing of the airframe tube (not actually trying to bend/break the tube or fins), if the tube breaks under light stress (or even the fins) the rocket shouldn't be flying. As others have said and if not I will say it....
"If you are going to 3D print a rocket make sure you know what the common issues and failure points are and make sure they are mitigated".

 

[Steve Shannon]

I don't believe Steve is actively trying to "break the rocket", applying light to moderate pressure to determine if something is loose or can break loose is reasonable, as would be light to moderate flexing of the airframe tube (not actually trying to bend/break the tube or fins), if the tube breaks under light stress (or even the fins) the rocket shouldn't be flying. As others have said and if not I will say it....
"If you are going to 3D print a rocket make sure you know what the common issues and failure points are and make sure they are mitigated".

Thanks for understanding what I’ve been trying to say, Rich.
It’s just squeezing the fin tips towards each other, testing the glue joints. I sometimes talk to the owner while I’m inspecting the rocket, telling them what I’m looking for:

“I’m trying to see if the motor can easily be pulled out. I’m flexing the fins to see what if I feel or hear anything from the glue joints. I’m checking how tight the rail buttons are. I’m checking to see how easily the nosecone slides out. How are your shock cords attached to the nosecone? Can I see? Do you have another quick-link on the other end? Did you tighten it down? How did you fold your chute? Does it slide out pretty easily?”

Like I said, the few times the fin glue joints have popped loose while I flexed them(no fins were actually hurt), I have helped the people understand why and I’ve helped them fix them so they could fly. They were actually grateful because they didn’t lose their rocket to a crash, and they learned something.

 

[Frederocket]

Thanks for understanding what I’ve been trying to say, Rich.
It’s just squeezing the fin tips towards each other, testing the glue joints. I sometimes talk to the owner while I’m inspecting the rocket, telling them what I’m looking for:

“I’m trying to see if the motor can easily be pulled out. I’m flexing the fins to see what if I feel or hear anything from the glue joints. I’m checking how tight the rail buttons are. I’m checking to see how easily the nosecone slides out. How are your shock cords attached to the nosecone? Can I see? Do you have another quick-link on the other end? Did you tighten it down? How did you fold your chute? Does it slide out pretty easily?”

Like I said, the few times the fin glue joints have popped loose while I flexed them(no fins were actually hurt), I have helped the people understand why and I’ve helped them fix them so they could fly. They were actually grateful because they didn’t lose their rocket to a crash, and they learned something.

I guess my understanding of what is an inspection differs from yours and a few others. However, I do agree with your intent. That being said, I would feel quite awkward if during my RSO inspection, I broke a fin or dented a air-frame on the flyer's rocket; "conditions I can for the most part determine by a visual inspection". OTH, physically checking motor retention, nosecone fit, rail buttons, and recovery attachment points, etc., for security is more than acceptable phisical security inspection items as they are attached items and not part of the actual structure.

I guess this is one of those issues we will agree to disagree on.