updated data after post-processing my first two APCP batches, Everclear

diff --git a/rockets/research/2019.01.07.mdwn b/rockets/research/2019.01.07.mdwn
index 7f3188314939219e18b835d59ad2656792410914..dae4d228782757655d340891803d34ded6e498b1 100755 (executable)
--- a/rockets/research/2019.01.07.mdwn
+++ b/rockets/research/2019.01.07.mdwn
@@ -1,7 +1,10 @@
 # Batch 2019.01.07 #
 
 # Batch 2019.01.07 #
 

-4 Terry-length Everyclear grains for 54mm cases, with 0.5 inch cores, 
-cast as two 6-inch-long double grains then cut and trimmed.
+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 
+cut, cored, and trimmed as necessary.
+
+The 54mm casting tube I'm using weighs 1.84g per inch.

 
 This was my first time mixing APCP propellant.  Used the 4.5qt mixer and
 hand packed with no vacuum processing.  The formula was taken from a pdf
 
 This was my first time mixing APCP propellant.  Used the 4.5qt mixer and
 hand packed with no vacuum processing.  The formula was taken from a pdf


@@ -11,12 +14,18 @@ These grains were cast on 2019-01-07.
 
 ## Results ##
 
 
 ## Results ##
 

-The batch size was too small, there was about 1/4" of the second casting
-tube left empty.
+The batch size was too small, so I couldn't fill the second casting tube, 
+which left grain 4 short.
+
+* Grain 1, 2.990" long, 163.7g gross, 5.50g casting tube, 158.20g net propellant
+* Grain 2, 2.992" long, 163.8g gross, 5.51g casting tube, 158.29g net propellant
+* Grain 3, 2.976" long, 163.4g gross, 5.48g casting tube, 157.92g net propellant
+* Grain 4, 2.650" long, 146.1g gross, 5.52g casting tube, 140.58g net propellant

 
 

-* Grain 1, gross, g casting tube, g net propellant
-* Grain 2, gross, g casting tube, g net propellant
-* Grain 3, gross, g casting tube, g net propellant
-* Grain 4, gross, g casting tube, g net propellant
+The length of grain 4 is estimated by measuring the average lack of fill on
+the full-length 3" casting tube section.

 
 

+The mass per unit length was within 0.1g/inch, which seems awesome.

 
 

+Since these grains were processed with the ones from the next day, see that
+batch for masses lost in post processing, etc.

diff --git a/rockets/research/2019.01.08.mdwn b/rockets/research/2019.01.08.mdwn
index 2d43d37e5122221ee1cb42849aa500dbe517c014..0112b4beb154a4cf48a975cf70ec18a881cbc5e9 100755 (executable)
--- a/rockets/research/2019.01.08.mdwn
+++ b/rockets/research/2019.01.08.mdwn
@@ -1,7 +1,10 @@
 # Batch 2019.01.08 #
 
 # Batch 2019.01.08 #
 

-4 Terry-length Everyclear grains for 54mm cases, with 0.5 inch cores, 
-cast as two 6-inch-long double grains then cut and trimmed.
+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 
+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
 
 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


@@ -11,10 +14,21 @@ These grains were cast on 2019-01-08.
 ## Results ##
 
 The updated batch size was just right, there was a bit of excess propellant
 ## 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.
+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.

 
 

-* Grain 1, gross, g casting tube, g net propellant
-* Grain 2, gross, g casting tube, g net propellant
-* Grain 3, gross, g casting tube, g net propellant
-* Grain 4, gross, g casting tube, g net propellant
+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.