(Courtesy of Star Rocketry)


Hypertek Fill Stem Mod for Those "BIG ONES"!


Korey Kline released the Hypertek "L" motor systems (and Hypertek "M" - now certified) to push those larger diameter heavier rockets into the atmosphere. But how am I going to get a large diameter rocket onto the current fill stem assembly that will only take up to a ½" rod and a 6" diameter rocket? Well, here is one solution to that problem.


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I drilled three holes at the midpoint between the hinge and the ½" rod sleeve. Then I inserted the three eye bolts that had a ¾" ID eye that would slip onto my ¾" rod. The system above can handle rockets up to 12" in diameter by adjusting the nuts on the eye bolts.








My son Scott (standing) and I have tested this system by launching a PML Pterodactyl with the Hypertek J250 at the Huntsville Area Rocketry Association’s (HARA) Ardmore, Alabama launch site. The launch went flawlessly, pushing the 20 pound dinosaur 630 feet into the air. At apogee it spread it’s 14’ wings, a Rocketman chute, and floated back to earth.




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