Loading ...
Sorry, an error occurred while loading the content.
 

Re: G motors for contest certification

Expand Messages
  • John DeMar
    ... When this question came up before TARC last year, I sacrificed a G35 and weighed the propellant. It is NOT over 62.5 grams. Trip added it to the list
    Message 1 of 202 , Jan 1, 2004
      Jay Calvert wrote:
      > I just sent an email to Ellis asking for clarification of the 82 grams vs.
      > 62.5 grams propellant question. I'll let the group know what I find out.

      When this question came up before TARC last year, I "sacrificed" a G35
      and weighed the propellant. It is NOT over 62.5 grams. Trip added it to
      the list of allowed motors.

      TRA does a simple method of weighing the motor before and after the burn
      to get propellant mass. This ends up including the delay and some liner
      material. That is where the higher number came from.

      It is also worth noting that the raw data from the TMT tests of the Ellis
      G35 have quite a bit of variability from motor to motor. This also holds
      true in the flights I've done (and seen). For the intro to engineering
      course we had at Syracuse University in Fall 2002, we used about 40 of them.
      One catoed. I also had one that blew through the ejection charge at ignition
      (20 degrees outside at the time, not sure if that had anything to do with it).
      I've also seen about 4 or 5 at launches and they all worked well.

      Hopefully, if Bob Ellis submits a batch to NAR S&T, the variability of
      the motors will pass the stricter NAR tests.

      -John DeMar
      NAR #52094
      http://delta.syr.edu/jsdemar
    • Kevin Wickart
      ... For the most part, they go for what the long-time R/C airplane hobbyists would call an ARF trainer. To those outside the hobby to start with it s a pretty
      Message 202 of 202 , Jan 5, 2004
        --- doug holverson <dholverson@...> wrote:
        >

        > Do these people buy something as sensible as an ARF trainer or
        > do they
        > gravitate to something hairier?


        For the most part, they go for what the long-time R/C
        airplane hobbyists would call an ARF trainer. To those outside
        the hobby to start with it's a pretty impressive craft that they
        can yank out of the box, rubberband (or whatever) the wing to the
        fuselage, attach a couple of simple linkages, and go outside to
        fly.
        It's once they get the hang of R/C flying that they start
        thinking that they might want to tackle something a little more
        involved, especially after seeing what the hobby veterans are
        flying at the "local" field, and starting to ask more in-depth
        questions at the hobby shop. Sensible, really, to learn the
        critical skills before risking dozens of hours of craftsmanship.

        --Kevin--

        __________________________________
        Do you Yahoo!?
        Find out what made the Top Yahoo! Searches of 2003
        http://search.yahoo.com/top2003
      Your message has been successfully submitted and would be delivered to recipients shortly.