Saturday, February 28, 2009
Sugar Motor Data
This is the test data for the motor used in
the RU-486, discussed in the previous post.
I thought about posting a pic of the actual
motor, but to a non-rocketeer, it looks like
a boring aluminum tube. To a rocketeer it
looks like an aluminum rocket motor that's
boring because it's not lit.
I've been into making sugar motors for
about 8 years now on an unsteady basis. I
started developing this Bates grain motor
right after my initial successes with small
disposable motors. Initial ground tests of
all motors were done with a peak reading
pressure guage in order to dial in the correct
nozzle size. I flew the 4th and 6th motors,
the 6th being the RU-486 flight. This is the
first time I've gotten to test these motors
on a proper motor test stand, unfortunately,
the pressure transducer had a broken wire,
so there is no chamber pressure graph.
We believe that the strain guage was not
properly calibrated and the unexpectedly high
ISP number bears this out. There is no doubt
though, this is an extreme motor.
I recently adjusted my motor labelling
nomenclature. 638-B7 means, Cooking batch
#6 for any 38mm motors, B for Bates geometry,
7th bates motor produced. Labels packed with
the reloads hold additional data, but this is
enough to I.D. the motor when referring back
to my notes.