Any way, my first attempt was last month with the igniter wire taped to the
fill stem. It didn't work, the gain was pot marked with burns but didn't
light. The wire needs to be taped to the grain itself on this grain. The L
worked well with the wire taped to the fill stem but the M is too big.

The 2nd try was Sat. the 25th. The Rocket is the Obsession III 15.1/2' by
11.6" glass covered PML tubing. With filled flight tank it weighed 95
pounds. It flew out of a 12 tall wood Launch Tower. The tower was built so
as to hold up the rocket and let the fill stem and blast deflector drop out
of the motor at ignition. I designed the drop at 1/2" . As it turned out
that wasn't enough. I should have dropped it out more like 1". I will check
this detail out more on the next flight.

I like the basic design of the drop fill stem in the launch towel because of
what Scott Bartel told me about his first flight. The force of the blast
bent the fill stem and blast deflector because it was only supported on one
side only. The tower design gave support to the blast deflector on all 4
sides. In fact it looks like it supported the stem too well. Any way it is
an easy fix, just hold the rocket up another 1/2".

We built the tower around the rocket as we prepped the rocket. We used the
tower (with one side open) as a cradle while working on the rocket. After
the rocket was finished prepped the last two side of the towel were
installed.

After prep, we took the combination out to the pad, stood it up, staked it
down to the ground and hooked up the wires and lines. After checking all the
electronics it took about a min. to fill the flight tank and we had a 10 sec
count down. At 0 the flames at the nozzle looked more like a blow torch. But
because the fill stem didn't drop enough to clear the "O" ring in the Kline
valve. the N2O couldn't flow. It was my bad design that caused the problem.
It took 7 seconds for the flame to burn through the 1/2" thick alum. blast
deflector enough for the fill stem to drop through the hole. Then the N2O
began to flow, and the rocket was off with a roar (a very big roar).

The heave rocket lifted off with 3.8 G that is a max. thrust of about 450
lb. and had a total burn time of about 10 seconds, but because of my mix up
the bell injector was damaged on the pad and didn't work right. It dumped
too much N2O and had a burn through at the top of the grain near the top of
the O2 tube on the fill stem. The burn through was late in the flight so
little damage was down to the rocket itself. Infact the PML motor mount tube
was only toasted a bit on the inside and will be reused. I would also assume
that the nozzle was also damaged by the long blast on the pad.

Overall alt. was about half of what was expected at 2500 feet, but all the
recovery devices etc worked as expected and the rocket had a soft landing a
few hundred feet from the pads.

>From my one screw up, the fill stem was burned up, the blast deflector was
burned through, the injector was burned, the grain burned through and the
nozzle was damaged. With all that, there is no question why the alt. was
low, but wow what a flight.