rharshberger
Well-Known Member
Any further updates on this project?
I am putting together my L3 package currently and would like to reference this thread as the technique I will be using for my fins. The only change in construction for me will be endgrain balsa instead of honeycomb and my upscale of the Cherokee-D will be a 5.5".
Just spotted this thread. Sorry for the slow start.
I am using an isogrid structure on the Apache stage of my 1/2 scale Nike Apache.
Isogrid is a structure developed by NASA to produce very light structures that have relatively isotropic properties. It was used, among other things, on the Delta IV, Orion CST-100 (and Skylab and the SST main tanks IIRC) and various other items.
https://en.wikipedia.org/wiki/Isogrid
Here is my take on it:
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Fins start in the build thread here: https://forum.ausrocketry.com/viewtopic.php?f=6&t=5019&start=31
I could tell you if it flew successfully, but we had 2.5 months of scrubs and delays due to weather, then the fire season kicked in. Waiting...
Have you considered T-nuts? They don't pull through as easily as the friction-fit inserts. Work great in plywood.
Search Google for "t nut" (I can't post pics at the moment )
Tim,
How about a u-bolt on ply bulkhead epoxied up in center tube. Use heavier back plate and thick ply with filet.
Can't seem to upload pic sorry
With these larger diameter, longer rockets, I'm worried about bending moments at the couplers. Are you doing anything special to secure the airframe around the couplers and around the payload bay?
I'm currently in my early L3 build stages with an 8" diameter model.
How is this for a slow build... Have the two couplers and two of the three airframes glassed now. I'm OK though, planned first flight is at Airfest 23.
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