Date: 01/24/04
CEG (Colorado Ex Group) get together for a day of static test fires at the Atlas launch site. The weather was about 40 to 50's but the wind was cold and made it more like the high 20's low 30's with some clouds. Still a good day to get out for some motor testing. Attending today was Steve Mashburn, Dale Netherton, Ed W. and his friends Hahn and Brady, and me. I did not have anything to light this time, I hung out taking pictures, video's and just gave everyone a hard time. We were going to use my newly remodeled thrust stand, but I needed to finish up a few things to get it right, so I was not able to bring it out. Dale brought his stand out so it was used instead.
Dale started off with his 38mm "I" motor using an Aerotech case and graphite nozzle he copied from the original. Part way through the burn half of the nozzle was popped out slowing to burn down due to the pressure drop. Upon examination the entire back half of the nozzle was gone. The case made it intact and he was able to get a pressure reading from the burn.
Next up was Steve's "Smokey Red" in which it was smokey but had no red, sorry Steve it had to be said (Hehe). The test was good never the less and I thought it had potential. Even without the right color it was a great motor.
Ed and his friends brought out a couple of sugar motors to test. They were looking for a longer burn time, somewhere around 4 seconds. I must say that they need some work as the first motor lit and burned for about half a second. Their second motor was a slower formula and burned a little bit longer, but not the 4 seconds they were looking for. Just like most of us, back to the drawing board.
Steve was prepping his 3 inch pink/fucia L motor while the sugar motors were being tested. He loaded the 3 inch case in Dales stand and got it ready to fire. 3...2...1 and it was off and running. at first it looked a little unstable but the plume changed and looked great for about .8ths of a second, then the motor blew. Upon looking at the video we had, it looked like the delay grain he put in may had dislodged (it was not in very tight in the Kosdon forward closure) and started floating around in the case which may have blocked the nozzle and over-pressurized the case. This may be the cause of the cato. Of course it took out Dale's stand so we were not able to test any more motors for the rest of the day.
Photo's from the 1/24/04 static tests day.
Date 05/16/04
The day was a little cold with overcast sky's as we made our way to the site. By the time we got there at 8:00am the clouds were burning off and it was turning out to be a nice day. The wind picked up a bit, but it was still a great day for testing motors. We only had two motors to test today. Both being Ken's. The first test was his AN 76mm 34 inch motor with an output of about 4700 Newton seconds. The pressure was about 425 psi and average of 180 psi of thrust for about 7 seconds. We tried something different where we put a video camera inside the bunker looking down at the motor and flame. We knew the camera was at risk, but Ken has his AN motors dialed in very well so we were ok with the thought. Turns out the video was awesome. See the video's below. The second motor was a 54mm AP motor. Ken's second attempt. Running a Kn of about 200 we thought it would be ok. Turns out the nozzle popped out and the pressure spike was over 1500 psi. We figured he may have ground some of the AP into a fine powder that may have cause the propellant burn too fast and overpressure. Video shows it all. I will be giving him the Tiger Tail formula. We found all but one of the gains and decided to burn them. They got so hot the Al slag that is usually left over was totally melted together in globs. Ken sent in his motor files from the Data Q (listed below) as well as his specs from that motor test.
Photo's from the 5/16/04 static tests day.
Videos:
AN 3 x34 inch case - Ken Swanks latest AN motor. (mpeg 3.6 meg)
AN 3x34 AN Motor - Another video taken from inside the bunker. Awesome! (mpeg 3.9 meg)
Kens new54 AP motor - May have grinded down the AP too much. (mpeg 1.4 meg)
Kens 54 motor - From another angle. (mpeg 1meg)
Grain burn - We burned the grain we found after the cato, they are kinda hot. (mpeg 6 meg)
Motor Specs.
Motor 75-34 test #1 5-16-04
Comments:
3 in casting tube = 154.9 g/48 in
Propellant A
Batch size 3000 g
Propellant wt 2796.7g (6.16 lb)
9 3.25 in segments
OD 2.5625
Bore 1.08
Density 0.0492 lb/cu in
nozzle 11/16 0.68
BTAR = 2.52 (1.32)
Max WT actual = not calc’ed psi
Max wall stress index = not calc’ed at wall thickness 0.125
burn time 6.98s
max thrust 205 lbs
median thrust 166 lbs
area 1057 lb.s (4698 ns)
max p 430 psi
median p 336 psi
mean p 307 psi
nozzle area 0.363 sq in
mass flow rate 0.88 lbs/s
Isp 189s wickman 1-9
c* 4077 ft/s Wickman pg 1-12 using mean p .
cf 1.36 Wickman 15-7
Web T = 0.74125in
burn rate 0.106 in/s
designation L 670
Cumulative a= 0.0049, n=0.536
Date 12/16/04
These reports start with the making of hybrid motors from a few members in the group.
First Hybrid - Ed and Don start making and testing their hybrid motors.
Second Hybrid - Ed and Don second test fire.
First Hybrid - A different angle.Second Hybrid - Different angle.
Second Hybrid - A different angle of second hybrid
Photo's from the 12/16/04 static tests day.