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

  • From: "Cliff Bates" <cliff@xxxxxxxxxxxxxx>
  • To: <sugarshot@xxxxxxxxxxxxx>
  • Date: Wed, 25 Dec 2013 15:36:41 -0800


    I'm not exactly known for my tact either Eric, but I think the frustration 
you expressed was a bit out of line.  As I finished reading your comment, I  
wondered if you had ever done any such tests yourself, or were just a side line 
critic.

    Rick, my hat is off to you on including the failures in the video.  As you 
said, most wouldn't have.  But in reality, that is where the learning curve is. 
 Otherwise it is simply doctored science, where nobody learns from the 
failure(s) because they were surpressed.  Consequently that causes someone else 
to repeat the same problem again, and no advancement is made.  A rabid problem 
in today's science, to "appear" all knowing.
    The thing is, Rick and the gang stuck it out, found the problem(s) by using 
their heads, and ended up with a good test.  We all learned from the 
problem(s), and if you think about it, learned more than if it had fired 
perfectly the first time. 
    
    I kind of wonder about the terrific amount of build up of slag in the 
diversion part of the exhaust nozzle however.  It would appear that in flight 
if this happened it could cause a considerable yawing in the trajectory.  
    Also it appeared to me that the exhaust velocity was noticeably lower than 
normal.  But I'm kind of negatively bias on this diffusion plate idea anyway.

    Cliff
  ----- Original Message ----- 
  From: Jeppe Locht, Mainstage Co. 
  To: sugarshot@xxxxxxxxxxxxx 
  Sent: Wednesday, December 25, 2013 1:37 AM
  Subject: [SS2S-Main] Re: Sugar Shot Weekly Activity Report -Dec.16-20, 2013


  And the prize for showing remarkable restraint despite fair reason to go 
ballistic, goes to Rick ;-)


  On Dec 25, 2013 03:52 "Rick Maschek" <rickmaschek@xxxxxxxxxxxxxx> wrote:

    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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