Site Map
Book List    

E-mail Ray

Latest firings in New Mexico

On 01 Oct 2000, the site was initiated by Brian Kosko, who fired a number of HPR class solids he had made. Keep checking back for video of the firings and test data.

In attendance were:

Brian Kosko - Propellant Design

Dave Johnson - Motor Assembly

Dennis Floyd - Technical Assistance

Rodney Earwood - Data Collection and Control

Terry Spath - Site Engineering

Ray Calkins - Site Manager, Photographer

The day's firings commenced with the caseless burning of a grain that had a void in it: 001001a.JPG.

For the instrumented firings, a small "H" motor started the data runs: 001001b.JPG. This one was a different formulation than Brian had previously tested, so it was a good idea to start small. The computer locked up during this run, either balking at the midday heat, or the 130+ VAC the generator was pumping out.

A shutdown, cooldown and generator adjustment got things going again with another small H motor, this one a "Quality Control" motor which ran nicely: 001001c.JPG. The data is here: in text form and thrust trace.

Okay, enough small stuff, time to start scaling things up: 001001d.JPG, in text form and thrust curve.

Not only did I miss the photo of this test, but the computer locked up and rebooted itself before the data could be saved. There will be a DC powered computer and better cooling next time to fix this problem.

This motor test 001001e1.JPG, was of a spectacular special effects motor with zinc and titanium added. Amazing amount of black smoke from that small thing: 001001e2.JPG and 001001e3.JPG. That cloud of smoke is every bit of 8 meters long by 10 meters high. Text data and thrust curve.

Time to scale up again. 001001f1.JPG, blew both closures quickly into the burn (001001f2.JPG), ejecting the grain out the back, and bending the metal stop on the thrust cradle as shown here: 001001f3.JPG. Note the unburnt grain sitting by the stand... A quick calibration check of the 1,000 lbf load cell showed no damage done there. The calibration remained true, on to the next motor. The failure happened so quickly after ignition that no appreciable thrust curve develops for this run, but a text file is interesting, showing a very low frequency resonance as the thrust structure rings from the casing failure.

Time to scale up again. The final burn of the day was this: 001001g.JPG, in text form and thrust curve. That's Brian Kosko, the motor's creator. The motor ignited and came up to pressure nicely, with a nice, steady burn with a steadily increasing exhaust note. About 3/4 through the burn, it over pressurized the case, fracturing at the forward snap ring grooves. The grain ejected forward around 5 meters away, where it burned in the open air until it was consumed. The case removed itself to the rear of the stand around 10 meters out in the desert. The load cell didn't survive this one. You can see in the text file how the strain gauge appears to have debonded about 3 seconds after the motor thrust dropped to zero. However, Brian provided a new load cell to replace the blown one, so testing can resume. There is hope the old load cell can be repaired as well.

Notice will be posted on the aRocket Forum when the video clips are up.

Valid XHTML 1.0!