Yes, I'm ripping off the Honey Badger fins. I wont pretend this is an original design or concept. Credit for this goes to Ryan and David, who's build
you can see here.
I contemplated several different ways of making fins. I did a few experiments with bending sheet metal but was unable to achieve consistent results. There have been few composite fin cans that have survived upper M3 flights, so there isn't a lot of examples of solutions to the aerodynamic heating problems. I settled for the honey badger design because A: it has been previously successful; B: because its relatively inexpensive and C: I was confident I could replicate it with my table saw. I bought a 3/16in sheet of LE Phenolic from McMaster-Carr for the leading edges and a sheet of 1/16in G10/FR4 for the fin core.
I put my circ saw blade on the table saw because I knew it had a 1/16in kerf. I enjoy having all 10 fingers, so I wanted to avoid a setup that would keep my fingers well away from the blade (Im talking to YOU Manny and Steve). The jig I made was essentially a track I could clamp the phenolic to that would slide along the table saw fence. That way I could just push the sled and not get near the blade at all.
Here's a photo of my jig on the table saw.
Here's a different angle where the cutting occurs.
After cutting a slot I took the plate over to the bandsaw to cut the strip out.
They came out pretty good if I do say so myself.
I cut out the 1/16 G10 cores with a jigsaw. No pics of that because that isn't interesting at all.
Here you can see the separate G10 and Phenolic pieces that make up each fin.
Ready to bond them.
After setting the core into the leading edge, I placed 2 1/32in spacers on each side of the fin. This was to ensure that the core was perfectly parallel with the leading edge.
I then set a sheet of fiberboard on them with a few pounds of lathe stock on top of it. This is just to add pressure and make sure everything comes out flat.
Here's a finished fin. I cut the excess strip off with the bandsaw and sanded it flat with the belt sander.
I'm happy with how these have turned out so far. Next up is reinforcing them with a few layers of CF.
Maybe if I had more time I'd like to explore different ways of making fins, but I'm working 40 hours a week and taking a condensed chem class, time isn't something I have a lot of. I'd like to do some research on metallic edge strips or efficient metal fin cans, but now just isn't the time.
Thanks for following,
Casper
Will need to get the story on the name sometime, too...
"The parachute rests in the nose cone," that's a quote from his write up. Also you can see in the OR file that there is a mass object...
