X-Git-Url: https://git.gag.com/?p=web%2Fgag.com;a=blobdiff_plain;f=rockets%2Fresearch%2F2019.01.08.mdwn;h=569fa8b16f5d099709dc6e09f2a153e555bc6211;hp=0112b4beb154a4cf48a975cf70ec18a881cbc5e9;hb=379c8282055dc56843ff3a55f7389cad23b3569c;hpb=a315fc632f2cf2c730a16e1557ca9d0fbefb6a91 diff --git a/rockets/research/2019.01.08.mdwn b/rockets/research/2019.01.08.mdwn index 0112b4b..569fa8b 100755 --- a/rockets/research/2019.01.08.mdwn +++ b/rockets/research/2019.01.08.mdwn @@ -1,34 +1,25 @@ -# Batch 2019.01.08 # +# Batch 2019.05.21 # -4 Terry-length Everyclear grains for 54mm cases, with 0.625 inch cores, -cast as two 6-inch-long double grains with 0.5" delrin coring rods, then +8 Terry-length Everclear grains for 54mm cases, with 0.625 inch cores, +cast as four 6-inch-long double grains with 0.5" delrin coring rods, then cut, cored, and trimmed. The 54mm casting tube I'm using weighs 1.84g per inch. -This was my second time mixing APCP propellant. Again used the 4.5qt mixer -and hand packed with no vacuum processing. Same formula as yesterday +Third time mixing APCP propellant. Again used the 4.5qt mixer and hand +packed with no vacuum processing. Same formula as previous batches. -These grains were cast on 2019-01-08. +These grains were cast on 2019-05-21. ## Results ## -The updated batch size was just right, there was a bit of excess propellant -so we can make density and burn rate measurements after cure. The excess -weighed in at 17.9g after cure. -* Grain 1, 2.980" long, 162.6g gross, 5.48g casting tube, 157.12g net -* Grain 2, 2.970" long, 162.0g gross, 5.46g casting tube, 156.54g net -* Grain 3, 3.010" long, 164.7g gross, 5.54g casting tube, 159.16g net -* Grain 4, 2.995" long, 163.6g gross, 5.51g casting tube, 158.09g net - -The mass per unit length was within 0.1g/inch, which seems awesome. - -In total for this batch and the previous day's, which were post-processed -together at the same time, there was 10.4g sanded off the grain ends and -64.7g of waste from core drilling the 0.5"-ish holes to 0.625". Really -leaves me wondering if it wouldn't be better to just start with the right -size coring rod for future batches and avoid the coring waste. Might leave -me wanting to rough the cores for better ignition? But, maybe not. Something -to ponder more. +* Grain 1, " long, g gross, g casting tube, g net +* Grain 2, " long, g gross, g casting tube, g net +* Grain 3, " long, g gross, g casting tube, g net +* Grain 4, " long, g gross, g casting tube, g net +* Grain 5, " long, g gross, g casting tube, g net +* Grain 6, " long, g gross, g casting tube, g net +* Grain 7, " long, g gross, g casting tube, g net +* Grain 8, " long, g gross, g casting tube, g net