[SS2S-Main] Re: Sugar Shot Weekly Activity Report - Dec.16-20, 2013

  • From: Rick Maschek <rickmaschek@xxxxxxxxxxxxxx>
  • To: "sugarshot@xxxxxxxxxxxxx" <sugarshot@xxxxxxxxxxxxx>
  • Date: Tue, 24 Dec 2013 18:52:49 -0800 (PST)

I can appreciate your comment. I could easily have left the four failed 
attempts out of the video and made it look like things went wonderful. I know 
many that try not to show things that don't work. 
This was the first time we did this type of motor. The tops of the grains were 
inhibited with polyester resin and a layer of pyrogen was painted across the 
top and down the two sides of the grain. During motor assembly, the floating 
nozzle slid forward and cracked the igniter's bridge wire, this was discovered 
after the first attempt and inspection of the igniter. On the second attempt 
with a new igniter, continuity was lost. On the third attempt, the igniter was 
not of sufficient intensity to ignite the pyrogen painted on the top surface. 
On the fourth attempt, a larger igniter was used and managed to burn the 
pyrogen painted on the top inbitited surface (seen in the 4th picture of the 
video) but failed to continue to burn down the sides of the grain. On the fifth 
attempt, a 0.125 thick slice of APCP propellant was cut from a 38mm grain and 
the igniter place in its center. That ignited the motor. This small K-class 
motor was to test this very thing,
 how to ignite these grains, would the sliver catcher work, and would this 
grain geometry burn as predicted. We were successful with these three things. A 
new bulkhead and igniter design has already been machined that should solve 
this problem.
If you look at our many previous videos of motor tests, you will see we have 
nearly 100% ignition on the first attempt. Thank you for your comments.

From: Eric Christy <sliderulelover@xxxxxxxxxxx>
To: "sugarshot@xxxxxxxxxxxxx" <sugarshot@xxxxxxxxxxxxx> 
Sent: Tuesday, December 24, 2013 6:02 PM
Subject: [SS2S-Main] Re: Sugar Shot Weekly Activity Report - Dec.16-20, 2013

You guys are EMBARASSING! Either you're lousy chemists, not able to get your 
mixture correct, or you're lousy electronics engineers, not able to make decent 
continuity between control board and igniter, or you're both. Which is it??? 
Suffice it to say, you bozos are very UNimpressive! When you grow some decent 
science, then get back to me. I bet you can't even balance the chemical 
reaction between Potassium Nitrate and Sorbital (sugar). You need to get that 
part right first before you try connecting to the igniter. 


> Date: Mon, 23 Dec 2013 22:25:28 -0600
> Subject: [SS2S-Main] Sugar Shot Weekly Activity Report - Dec.16-20, 2013
> From: richard.rocketry@xxxxxxxxx
> To: sugarshot@xxxxxxxxxxxxx
> Highlights of recent developments on the DoubleSShot project
> ---------------------------------------------------------------------------------------
> -As planned, Rick Maschek test fired the 89mm (3.5”) 2-grain rocket
> motor with DD-slot grains on Saturday Dec.21st. The test firing was
> conducted at the FAR site, with the motor mounted nozzle down on one
> of the vertical test stands. The base of the stand was fitted with a
> blast deflector to help prevent smoke from obscuring the pressure
> gauge used to record chamber pressure. This worked well, and good
> pressure readings were recorded over the full duration of the burn,
> which was nominal. Maximum chamber pressure was about 260 psi
> (1.9Mpa), which compares well with the predicted pressure of 248 psi.
> Due to problems with the igniter, the planned firings of the 4-grain
> and 6-grain motor had to be postponed. Rick will be modifying the
> forward bulkhead with an igniter fitting to prevent a similar igniter
> issue from re-occurring.
> Rick and Richard Dierking setting up the motor:
> http://sugarshot.org/downloads/setup.jpg
> Richard Dierking connecting the pressure gauge:
> http://sugarshot.org/downloads/setup1.jpg
> Motor at full thrust:
> http://sugarshot.org/downloads/thrusting.jpg
> Gauge reading at full thrust:
> http://sugarshot.org/downloads/gaugereading.jpg
> DD-slot grain details:
> http://sugarshot.org/downloads/dd_grain.pdf
> Video:
> http://www.youtube.com/watch?v=h1mYHtsD7a8&feature=youtu.be
> (video courtesy Rick Maschek)
> -Richard has made further progress on fabricating the carbon composite
> nozzle exhaust cone for the VIC-2 motor. All 10 plies of carbon
> prepreg were wrapped around the mandrel. After each ply was laid,
> heat-shrink tape was wrapped around the prepreg, then shrunk using a
> heat gun to consolidate the layers. The product was then vacuum bagged
> in preparation for curing. Curing will be done in an autoclave at
> elevated temperature (300F/150C) and pressure (4 bar).
> --------------------------
> -Sugar Shot to Space is on facebook. Check us out.
> http://tinyurl.com/2exr92k

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