# Batch 2018-batch-02 # 4 grains 80mm long for 54mm cases, with 0.5 inch cores These grains were cast as a demo for college students on Monday. The simulator says we need 200g of fuel per grain, so the batch size will be 800g (plus a bit for the pan made up by re-melting previous scraps): * 65% KNO3, 520g * 35% Sorbitol, 280g * 1% red iron oxide, 8g, added after melt * 12 drops Polystep-B1, added before pour using eye dropper This formula is completely fluid with 225F indicated on the Presto Multicooker, but viscosity is noticeabley lower making for easier pouring at 250-275F. Grain fill lines 73.6mm from the bottom of the casting tube. These grains were cast on 2018-12-17. ## Results ## * Grain 1, 198.8g gross, 5.78g casting tube, 193.0g net propellant * Grain 2, 194.1g gross, 5.82g casting tube, 188.3g net propellant * Grain 3, 196.6g gross, 5.78g casting tube, 190.8g net propellant * Grain 4, 201.1g gross, 5.80g casting tube, 195.3g net propellant