When this nose cone does its job, dinner gets cooked at Mach 3. The four-inch composite part was laid up in fiberglass for the High Steaks rocket, where the plan is aerothermal cooking during the flight, and the payload side gets equal care: an internally spiked aluminum heat sink, turned and milled to hold the meat while isolating that heat from the rocket body.
The construction path rewards a close read. A two-piece mandrel came off an Original Prusa XL in red filament, the halves drawn tight by a 1/4-20 threaded rod. Over that form, Titan 3XL latex acted as the release barrier, and nine plies of biaxial braided sleeving were wetted out with an epoxy system using 2060 hardener, with a vacuum degassing chamber in the setup. A blunt copper nose tip cup caps the front, the aft fin tabs are red-anodized 6061 aluminum from a sponsor, and the tool list also covered a Tormach CNC mill and a lathe.
The latex stage fought back. After the condoms tore repeatedly on the first try, BPS.space sanded the mandrel and added Super Lube grease plus Stoner E236 release spray. Getting the cured shell free went no better: striking the internal threaded rod, then driving an aluminum drift pin into the crown, left the printed mandrel collapsed inside, still gripping.
That leaves a genuine open question. The bonded assembly spent two hours in a domestic freezer to see whether thermal contraction would let go of the PLA, and the outcome has not been shown. Freezer contraction as a release method looks like a smart, low-force idea to me.
Project by BPS.space. Watch it on their YouTube channel: