OK----- Original Message ----- From: "Richard Nakka" <richard.rocketry@xxxxxxxxx>
To: <sugarshot@xxxxxxxxxxxxx> Sent: Monday, December 23, 2013 8:25 PM Subject: [SS2S-Main] Sugar Shot Weekly Activity Report - Dec.16-20, 2013 Highlights of recent developments on the DoubleSShot project --------------------------------------------------------------------------------------- -As planned, Rick Maschek test fired the 89mm (3.5”) 2-grain rocket motor with DD-slot grains on Saturday Dec.21st. The test firing was conducted at the FAR site, with the motor mounted nozzle down on one of the vertical test stands. The base of the stand was fitted with a blast deflector to help prevent smoke from obscuring the pressure gauge used to record chamber pressure. This worked well, and good pressure readings were recorded over the full duration of the burn, which was nominal. Maximum chamber pressure was about 260 psi (1.9Mpa), which compares well with the predicted pressure of 248 psi. Due to problems with the igniter, the planned firings of the 4-grain and 6-grain motor had to be postponed. Rick will be modifying the forward bulkhead with an igniter fitting to prevent a similar igniter issue from re-occurring. Rick and Richard Dierking setting up the motor: http://sugarshot.org/downloads/setup.jpg Richard Dierking connecting the pressure gauge: http://sugarshot.org/downloads/setup1.jpg Motor at full thrust: http://sugarshot.org/downloads/thrusting.jpg Gauge reading at full thrust: http://sugarshot.org/downloads/gaugereading.jpg DD-slot grain details: http://sugarshot.org/downloads/dd_grain.pdf Video: http://www.youtube.com/watch?v=h1mYHtsD7a8&feature=youtu.be (video courtesy Rick Maschek) -Richard has made further progress on fabricating the carbon composite nozzle exhaust cone for the VIC-2 motor. All 10 plies of carbon prepreg were wrapped around the mandrel. After each ply was laid, heat-shrink tape was wrapped around the prepreg, then shrunk using a heat gun to consolidate the layers. The product was then vacuum bagged in preparation for curing. Curing will be done in an autoclave at elevated temperature (300F/150C) and pressure (4 bar). -------------------------- -Sugar Shot to Space is on facebook. Check us out. http://tinyurl.com/2exr92k