Monday, July 15, 2013

This Is Not the Rocket You Are Looking For

At yesterday's launch, Ron Hill offered me the remains of a fireworks rocket that he found. The fins looked nice and seemed very sturdy, so I accepted.  It is also perfectly symmetric and the fins show no signs of warping.  He relayed the story of a fire that was blamed on model rocketry...and the photo shown was one of these. Obi Wan's famous line came to mind and I named the new rocket as shown in this post's title.

The body is close to 29mm and fits a 24mm motor pretty well. The business end is thinner and will accommodate an 18mm nicely.

To get the motor out, I inserted an spent E9 case from the top, flipped it over, and gave the nozzle a good whack with a punch and a big ball-peen hammer. The motor popped right out. The motor itself is plastic and the nozzle end is moulded in. Clay is backfilled to form the nozzle. The motor is 18mm in diameter and is a little shorter than the standard 70mm in length. This makes me wonder how such a case might lower the price-point of modroc engines. It could be that these run at a lower pressure than Estes motors, so there may not be any benefit.

This will make a cute little modroc. Tonight, I'll decide on how to install the motor mount and come up with some design options.