1 # Batch 2017-batch-03 #
3 6 grains of 29mm using erythritol, intended to be a reloads for the longest
4 GMA 29mm snap-ring case. Grain length 41mm with 1mm spacing per grain, so
5 we'll make the casting tubes 42mm long. Delrin coring rods of 5/16" diameter.
7 Formula for a batch size of 175g:
9 * 65% KNO3, 113.75g, taken from the big bucket
10 * 35% Erythritol, 61.25g
12 The multi-cooker was preheated to about 250F with the lid on. Temp was
13 increased during melting to 300F indicated.
15 These grains were cast on 31 May 2017.
19 <!--Begin motor 29mm 6-grain Erythritol #14 HTML export from MotorSim-->
20 <table class='motor' style='text-align: left; border: 1px solid black'><tr><th colspan='6' class='title'>29mm 6-grain Erythritol #14</th></tr><tr class='summary'><th>Rating:</th><td>43% H-162</td><th>Max Pressure:</th><td>5.92 MPa (859 psi)</td></tr><tr class='summary'><th>Total Impulse:</th><td>216 Ns</td><th>Specific Impulse:</th><td>133 s</td></tr><tr class='summary'><th>Max Thrust:</th><td>206 N</td><th>Volume Loading:</th><td>70%</td></tr><tr class='summary'><th>Average Thrust:</th><td>162 N</td><th>Fuel Mass:</th><td>165 g</td></tr><tr><td colspan='4' class='thrust'><img src='http://chart.apis.google.com/chart?chxt=x,x,y,y,r,r&chs=400x200&cht=lxy&chco=3072F3&chds=0,1.36,0,206.37&chxr=0,0,1.36|2,0,206.37|4,0,46.39&chd=t:0,0,0.03,0.07,0.11,0.17,0.25,0.36,0.52,0.69,0.73,1.05,1.2,1.21,1.21,1.21,1.21,1.21,1.21,1.21,1.21,1.27,1.36|0,11.17,113.77,132.54,140.92,151.05,164.61,181.51,198.8,206.37,206.02,177.47,152.17,142.48,132.97,123.64,114.51,105.58,96.88,88.42,80.21,1.09,0&chxl=1:|s|3:|N|5:|lbf&chxp=1,50|3,50|5,50' width='400' height='200' alt='null' /></td></tr></table>
21 <!--End motor 29mm 6-grain Erythritol #14-->
26 Average casting tube mass 1.13g.
28 * Grain 1, ?g gross, ?g net
29 * Grain 2, ?g gross, ?g net
30 * Grain 3, ?g gross, ?g net
31 * Grain 4, ?g gross, ?g net
32 * Grain 5, ?g gross, ?g net
33 * Grain 6, ?g gross, ?g net
35 With a 10.00" liner, 14/64" nozzle throat, buna-n o-rings, simulation says
36 this makes a 37% H-156, 208 Ns, with about a 1.2 sec burn.