From 5c478d87c187287c8d77a2f331f6732d7e732de5 Mon Sep 17 00:00:00 2001
From: Bdale Garbee <bdale@gag.com>
Date: Tue, 24 Oct 2017 11:57:16 -0600
Subject: [PATCH] need the referenced files, too!

---
 rockets/research/2017-batch-09.mdwn | 46 +++++++++++++++++++++++++++++
 rockets/research/2017-test-13.mdwn  | 40 +++++++++++++++++++++++++
 2 files changed, 86 insertions(+)
 create mode 100755 rockets/research/2017-batch-09.mdwn
 create mode 100755 rockets/research/2017-test-13.mdwn

diff --git a/rockets/research/2017-batch-09.mdwn b/rockets/research/2017-batch-09.mdwn
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+# Batch 2017-batch-09 #
+
+8 grains of 75mm using sorbitol, intended to be a reload for my CTI Pro75 6xl 
+case with Loki nozzle and forward closure.  Grain length 4.375" with 0.125" 
+spacing per grain, so we'll make the casting tubes 4.5" long.  Delrin coring 
+rods of 0.75" diameter.  
+
+To overcome shrinkage noticed in the last batch, fill lines set based on the
+total 4.5" casting tube length, on the assumption that any shrinkage will
+provide sufficient inter-grain spacing.
+
+Formula for a batch size of 4800g:
+
+* 65% KNO3, 3120g
+* 35% Sorbitol, 1680g
+* 1% red iron oxide, 48g, added after melt
+* 72 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.
+
+These grains were cast on 15 October 2017.
+
+## Results ##
+
+This batch made for a pretty full Presto, and a fairly long time coming up
+to temperature.  It seems like 5kg might be the most propellant I should try
+to melt at one time.  As an aside, that means for my 6" O project, we'd be
+melting and casting one grain at a time...
+
+Average casting tube weight 15.3g.
+
+* Grain 1, 542g gross, 527g net
+* Grain 2, 548g gross, 533g net
+* Grain 3, 552g gross, 537g net
+* Grain 4, 546g gross, 531g net
+* Grain 5, 544g gross, 529g net
+* Grain 6, 540g gross, 525g net
+* Grain 7, 528g gross, 513g net
+* Grain 8, 538g gross, 523g net
+
+Total propellant load 4218g.  That's enough lower than the anticipated mass
+that I decided to "top off" the grains with more melted propellant from the
+left-overs in this batch.  Will re-weigh after they cool/cure.
+
+
diff --git a/rockets/research/2017-test-13.mdwn b/rockets/research/2017-test-13.mdwn
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+# Test 2017-13 #
+
+8 grain 75mm sorbitol motor with pyrodex pellet ignition in 4-inch Wildman
+rebuilt airframe at Tripoli Colorado Hartsel.
+
+CTI Pro75 6xl case, Loki #52 (long) nozzle with 2 o-rings, CTI forward and aft 
+closure rings, forward bulkhead from Terry's pile machined to have 0.5" inside 
+snap ring plus 0.25" inside liner, with two o-rings, one pushing against liner.  
+Liner 37" long with just under 36" available for fuel load.
+
+Original simulation says this should be a a 26% M-2291 with 6138 Ns total 
+impulse, 869 psi max, 75% volume loading, and about 2.3 seconds burn 
+time.  After casting and weighing the grains, the adjusted simulation says
+this will be a 5% M-1785, 699 psi, 67% volume loading, and about 2.7secs burn.
+
+## Results ##
+
+Flown at last Tripoli Colorado launch of 2017 at the Hartsel launch 
+site.  Perfect flight, no damage.  Mach 1.1 on the way to 13711 ft AGL 
+by GPS, with a 2.8 sec burn time.  Winds at ground level 5-7mph, used
+Terry's launch trailer (20 ft 1515 rail), landing was 1 mile to the SSE,
+across the creek on state owned land south of the road.  Crowd response
+was very positive.  Largest sugar motor known to have been flown in 
+Colorado to date.  Spectacular!
+
+Flight data logged as sn 3121, flight 4 on 2017-10-22.  
+
+Used a Chinese e-match with 2 pyrodex pellets on a 1/8" dowel inserted so
+the aft end of the pellets was 36" from the aft end of the case.  The time
+from button press to smoke and then to acceleration was surprisingly short!
+
+Terry Lee captured launch video.
+
+I captured high-speed still of the launch.
+
+The acceleration plot looks pretty clean, with some bumps near burn-out that 
+strike me as maybe being related to propellant flaking off the inside of the 
+casting tubes?
+
+
-- 
2.30.2