Prepped 5 rockets for Sunday's CMASS launch in Amesbury MA. Left to right: Honey Badger (Estes Doorknob), KSP-II (LOC Graduator), NCR SA-14 Archer, LOC Athena and SunDiver (LOC Sandhawk). Also assembled my first reload - an AT G64-4, which will be powering SunDiver.
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I wasn't going to go, but you are tempting me. I only have one super simple rocket to fly, though, and I'm not sure it's worth the drive. I guess, since CMASS seems to be a NAR club, they never have any "experimental" motors there? And I really should burn the gunk out of my car's engine once in a while. Will there be any vendors? What's the altitude limit there? On reviewing the wind forecast, I guess everyone will be pretty conservative with altitude, unless they have an RC rocket glider or something. Hmmmm...
Snap! I've been using the same "re-purposed" kitchen item for the past few years. Works well. From the altimeter's I've put in it, the hand pumping gives a bit of a saw-tooth ascent curve so you have to pump quickly to avoid a false apogee being detected. My altimeters have clocked 17,000ft in there!
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Can you use something like that to calibrate your altimeter too? What would you check it against? I have a couple of vacuum pumps, but I doubt a vacuum gauge is accurate enough for checking the calibration of an altimeter. One could turn an ordinary aquarium pump to a vacuum source for a virtual 5,000 feet of altitude.
Laminated a second plywood fin with Flax cloth materials for the "Flax Capacitor" my Level 3 organic rocket concept.
Same method as before - Fin core is 5.6mm marine plywood; a triple flax sandwich each side using 200gsm and 300gsm flax cloth. Oven dried the flax laminations at 110degrees C for 15mins just before laminating.
Used a total of 300gms of bio epoxy in the process to ensure the flax fibres got a good soaking into their cores, which is a known challenge of using organic material versus f/glass. The laminates went on, reverse layer cake fashion as before, peel ply and absorbent material on top. Vacuum bagged using my food saver appliance.
Took 3 hours to cure to leather stage. De-bagged and trimmed. I weighted the peel ply and absorbent material with the excess epoxy that was drawn into it - 200gms total, so a big wastage of epoxy to get the required soaking and bonding.
Got any info or links on the structural properties of this stuff? I gotta wonder how they make bio-epoxy without using refined dead dinosaurs. Have you considered infusion? Not something I've tried just yet myself, and my bags, on the rare occasion I do it, tend to have frustrating little leaks.
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As far as what I did, rocket-wise yesterday I was out for a walk and saw that someone was throwing out metal pipe that looked like it might be the right ID for my Jetex fuel molds. It turned out to be exactly the right ID. Upon review this morning, it turned out I had a piece of PVC electrical conduit that could be persuaded with heat to go over the pipe to make it match the diameter of my other molds. So I cut three molds and added the conduit, with epoxy, to make them match my tooling. Maybe later today I'll wax the molds and mix up some fuel, which is all ready except for the epoxy. Hmm... maybe I'll try hair gel as mold release again. I have a vague memory that it worked well. Maybe I won't have to ream the molds afterwards.
