I've watched this thread for awhile now and think I may have some experience
that is relevant. First, I've launched several flippy fin rockets using a 5
foot long section of ABS pipe that is closed at one end with a screw-in
plug. The rocket is loaded into the tube nose first from the open breech.
the igniter must be at least 18" long. wadding is stuffed around the base of
the rocket to help protect it from the heat of the exhaust. the igniter
leads are then threaded through a hole in the screw cap. The cap is then
secured. With the tube locked in the upright position, the rocket is
launched. The tube acts as a gun barrel and the wadding serves to help
confine the exhaust. Needless to say, it rips out of the tube. I've used
G55s. F102s, and an assortment of other 24mm motors ranging from E-G and all
have worked perfectly.
The second method I've used uses the same tube but this time, it's 4" in ID.
The fins of the rocket are fixed rater than folding and a seal is maintained
using Styrofoam spacers that act like a sabot. Ignition is done the same way
and the results are the same as well except that acceleration out of the
tube is faster due to the lower weight of the rocket and the much better
seal at the breech. Not exactly a piston launcher but the result is very
much the same.
R. J. Talley
Teacher/James Madison Fellow
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