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

  • From: monsieurboo@xxxxxxx
  • To: sugarshot@xxxxxxxxxxxxx
  • Date: Wed, 25 Dec 2013 10:02:12 -0500 (EST)

Nice burn!  In the absence of a thrust curve, this looked and sounded like a 
neutral burn with roughly 7+ seconds at full thrust.  The slo-mo of the 
pressure gauge confirms the chamber pressure stabilized quickly at a plateau.*  
The sliver sieve also seemed to work, and all its holes looked patent after the 
test fire.  I did see, at 3:56-57, a gum-wrapper size piece of thin metal/thick 
foil fly through the frame.  Any idea what that was?  

Looks to me like the new grain design is a winner.   It makes me start to 
ponder how well it'd scale down!

As for the ignition, well ... thermite???  ;-)

Cheers,
Mark L.
DC

 
* You might consider sticking one of those cheap quarter-size stick-on digital 
clocks on the test-stand girder within the slo-mo camera frame so the viewer 
could directly correlate time to pressure ... not that it would've made much 
difference with this burn.

 

 

-----Original Message-----
From: william colburn <space1space@xxxxxxxxxxxxx>
To: sugarshot <sugarshot@xxxxxxxxxxxxx>
Cc: sliderulelover <sliderulelover@xxxxxxxxxxx>
Sent: Tue, Dec 24, 2013 10:34 pm
Subject: [SS2S-Main] Re: Sugar Shot Weekly Activity Report - Dec.16-20, 2013



The history of the development of nearly any new design is either replete with 
failures or is somehow successful. The failures delineate and outline the 
parameters 
needed to address and their limits. In fact "Off-limits" testing is often done 
to survey the boundaries of successful and non successful dimensions. A success 
at the outset does not guarantee continued success.


Two years worth of development at China Lake for the first double-base rocket 
motor. Hundreds of failures amongst a few successes.


In a rocket motor there are too many factors to consider and their multiple 
interactions; as mentioned above, a success is just a lucky event in testing a 
new design.


When at Thiokol, I heard many an explosion coming from the competitor rocket 
company across the way. We had a few also despite having thermo, aero, 
ballistic, grain design, mechanical, process, and propulsion engineers.


It is not an easy go and perserverance is a necessary trait in the propulsion 
biz.


BC

 
Gravity is a Stern Mistress..
                   The Tick.


  
 
 
 
   From: Rick Maschek <rickmaschek@xxxxxxxxxxxxxx>
 To: "sugarshot@xxxxxxxxxxxxx" <sugarshot@xxxxxxxxxxxxx> 
Cc: "sliderulelover@xxxxxxxxxxx" <sliderulelover@xxxxxxxxxxx> 
 Sent: Tuesday, December 24, 2013 6:52 PM
 Subject: [SS2S-Main] Re: Sugar Shot Weekly Activity Report - Dec.16-20, 2013
  
 



Eric, 
 
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.
 
 
Rick
 
 
 




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. 


Eric






> 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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