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3 second shut down problem...........

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  • Tim Soukup
    Hey, Just thinkin outloud...... How is the 3 Second time period for activation going to be enforced? What I mean is,..... does a judge just arbitrarily
    Message 1 of 8 , Nov 17, 2007
      Hey,

      Just thinkin' outloud......

      How is the "3 Second" time period for activation going to be enforced?
      What I mean is,..... does a judge just arbitrarily count to 3? We
      all know what happens during a flyaway........first you have the "Oh-
      $#it"---It's Loose" reaction.....then you look for a place to hide or
      run.......(preferrably AWAY from ANDY).So may I ask, "Who starts the
      shutoff clock".......
      Seems to me, this is going to open up an entirely NEW protest round,
      as you really can't effectively time a shutdown within that time-
      period......and no shutdown is going to be "Immediate" either.

      Next, what do you do when there is a collision ( "WHAM" )_and one
      model bites the dust, but the other model is left still flying, but
      on only ONE LINE? Next, it breaks free but doesn't shutdown. We've
      all seen some variation of this scenario.......

      The pilot can always claim that the shutoff was damaged in the
      collision and rendered inoperable. How do we settle this? I hope
      that when they unilaterally implement this ruling, they've thought of
      how it's going to be enforced and to what end?.....DQ the flyer? IT
      May not be his fault. What if the plane hits the ground in "about 2
      seconds" and the engine didn't shutdown completely? IS the flyer
      penalized?

      Just rambling thoughts
      Soukup
    • chicken_lovernz
      That is why a lot of F2D fliers are so angry, the proposed rules were cut and pasted from Fast combat with no mention of any of the points you have mentioned.
      Message 2 of 8 , Nov 17, 2007
        That is why a lot of F2D fliers are so angry, the proposed rules were
        cut and pasted from Fast combat with no mention of any of the points
        you have mentioned. The sub committee simply stated that shut offs
        work in Fast so they will work in F2D both physically and with regards
        to the rules. I think they have changed there view slightly when
        people pointed these things out to them which is what started this
        whole debate.

        Rather then the 3 second time limit maybe it should be "The shut off
        must cut the engine within the boundaries of the flyaway zone." A lot
        easier to police/judge?

        The only official current rules regarding shut-offs in F2D I know of are:

        F2D Combat 4.4.5, 4.4.6, 4.4.12, 4.4.15
        Add the following paragraph to section 4.4.5 immediately prior to
        "Note": An effective engine shut-of device will be compulsory. Amended
        at the F2 Technical Meeting and unanimously approved by the Plenary
        Meeting. Effective 01/01/09. Note: The F2 Sub-committee recognizes the
        seriousness of the situation. It will conduct F2D shut-of device tests
        beginning July 2007 and produce recommendations to the Bureau meeting
        of December 2007 for inclusion on the Plenary Agenda for March 2008.
        The three further rules in this proposal 4.4.6, 4.4.12, 4.4.15 were
        withdrawn pending these recommendations.

        Cheers
        Chris


        --- In combat-l@yahoogroups.com, "Tim Soukup" <trsoukup1@...> wrote:
        >
        > Hey,
        >
        > Just thinkin' outloud......
        >
        > How is the "3 Second" time period for activation going to be enforced?
        > What I mean is,..... does a judge just arbitrarily count to 3? We
        > all know what happens during a flyaway........first you have the "Oh-
        > $#it"---It's Loose" reaction.....then you look for a place to hide or
        > run.......(preferrably AWAY from ANDY).So may I ask, "Who starts the
        > shutoff clock".......
        > Seems to me, this is going to open up an entirely NEW protest round,
        > as you really can't effectively time a shutdown within that time-
        > period......and no shutdown is going to be "Immediate" either.
        >
        > Next, what do you do when there is a collision ( "WHAM" )_and one
        > model bites the dust, but the other model is left still flying, but
        > on only ONE LINE? Next, it breaks free but doesn't shutdown. We've
        > all seen some variation of this scenario.......
        >
        > The pilot can always claim that the shutoff was damaged in the
        > collision and rendered inoperable. How do we settle this? I hope
        > that when they unilaterally implement this ruling, they've thought of
        > how it's going to be enforced and to what end?.....DQ the flyer? IT
        > May not be his fault. What if the plane hits the ground in "about 2
        > seconds" and the engine didn't shutdown completely? IS the flyer
        > penalized?
        >
        > Just rambling thoughts
        > Soukup
        >
      • Iskandar Taib
        ... Three seconds is actually plenty long. Anything longer is really really long, and would be plenty obvious even without a clock. In any case, put the
        Message 3 of 8 , Nov 17, 2007
          Tim Soukup <trsoukup1@...> wrote:

          > How is the "3 Second" time period for activation
          > going to be enforced?
          > What I mean is,..... does a judge just arbitrarily
          > count to 3? We
          > all know what happens during a flyaway........first
          > you have the "Oh-
          > $#it"---It's Loose" reaction.....then you look for a
          > place to hide or
          > run.......(preferrably AWAY from ANDY).So may I ask,
          > "Who starts the
          > shutoff clock".......

          Three seconds is actually plenty long. Anything longer
          is really really long, and would be plenty obvious
          even without a clock. In any case, put the shutoffs in
          the control of the judges and the problem goes away.

          > Next, what do you do when there is a collision (
          > "WHAM" )_and one
          > model bites the dust, but the other model is left
          > still flying, but
          > on only ONE LINE? Next, it breaks free but doesn't
          > shutdown. We've
          > all seen some variation of this scenario.......

          Here's where the radio shutoff works.. you don't have
          to have a flyaway for the judges to hit the kill
          switch. If you see an airplane hanging on one line, or
          a really bad line tangle, kill the engines (and the
          match clock). You can restart after the mess is sorted
          out.

          > The pilot can always claim that the shutoff was
          > damaged in the
          > collision and rendered inoperable. How do we settle
          > this? I hope
          > that when they unilaterally implement this ruling,
          > they've thought of
          > how it's going to be enforced and to what
          > end?.....DQ the flyer? IT

          Examine the plane after it comes down. If it's damaged
          it won't get too far.

          Iskandar
        • henning.forbech
          If you read the proposals for new combat rules you will find both a 3 second AND a 5 second rule.
          Message 4 of 8 , Nov 18, 2007
            If you read the proposals for new combat rules you will find both a 3
            second AND a 5 second rule.
            (http://groups.yahoo.com/group/combat-l/files/clprprule1107.doc)

            The 3 second rule:
            "Demonstration of the engine shut-off device may be required by the
            judges before each heat. The engine shut-off device must stop the
            engine within 3 seconds of activation. Additional demonstrations may
            be requested by the judges after the heat"

            The 5 second rule:
            "In the event of a flyaway where the engine shut-off device does not
            stop the engine within 5 seconds"

            This discussion on the activation time is not new.
            One year back Doc Jackson made the first proposal for mandatory shut-
            off in combat and he used a 2 second rule. Back then I made an
            alternative proposal with the 3 and 5 second rules.

            /Henning Forbech




            PS: Here is some of the old background information to 3 and 5 second
            rules:

            Section 4.4.6: Controls - Technical Verification:
            "In the demonstration the shutoff must stop the engine within 3
            seconds of activation."
            Last year I did some experiments with a simple spring system that
            shuts off the fuel supply by squishing the fuel line. The engine
            stopped after approximately 1.9 seconds which is very close to the 2
            seconds proposed by Laird Jackson.
            A 2 second limit might lead to discussions on how to measure the
            response time in the demonstration. When has the engine actual
            stopped? When the engine is not making any combustion any more, when
            it is not turning over anymore or when the propeller comes to a
            complete stand still?
            With a shutoff system that stops the fuel supply a combat engine will
            normally stop working after 1.5 seconds and will typically come to a
            complete stand still after 2.5 seconds. Therefore a 3 seconds limit
            seems more suitable for practical use.
            You will find a video clip with the test here:
            http://www.modelflyvning.dk/f2d.htm

            Section 4.4.15: Cancellation of the Flight:
            "In the event of a flyaway the pilot shall be disqualified if the
            shutoff device does not stop the engine within 5 seconds."
            In this situation the time limit is set a little higher than during
            the demonstration.
            The idea is to let the technical verification ensure that the shutoff
            system is capable of bringing the engine to a fast stop. In the event
            of a flyaway it should then only be necessary to observe if the
            shutoff system is working or not.
            During a flyaway it will be very difficult to measure the exact
            reaction time for the shutoff system. The time keepers will typically
            be seeing the midair collision but hearing the engines stopping.
            The distances involved are far too big for a visible observation of
            the propeller movement, so the time keepers must rely on the sound of
            the engines.
            In a situation where a model is flying away from the timekeepers the
            delay of the sound can be as much as 0.35 seconds!
            (distance across the circle: 35 m, model flying 2 seconds at 42 m/s,
            speed of sound: 344 m/s)
            By setting the time limit for the flyaway situation higher than the
            test situation, we can eliminate a lot of discussion on how the time
            measurement was done during the flyaway, but we will still be able to
            disqualify a pilot with a non-working shutoff.


            For more information visit:
            http://www.modelflyvning.dk/f2d.htm - look for: "Early proposals for
            shut-off rules:"

            or find it here:
            http://www.modelflyvning.dk/linestyring/combat/shutoff/docs/Forbech
            comments.pdf
          • kb1_us
            we are required to demonstrate the shut-off prior to a match being flown here. It s a good way to warm up the engine for the instant starts required in our s/l
            Message 5 of 8 , Nov 19, 2007
              we are required to demonstrate the shut-off prior to a match being
              flown here. It's a good way to warm up the engine for the instant
              starts required in our s/l event as well as fast. There have been
              shut-off's that do not pass the test mostly because of poor
              maintenance.It's a good way to be sure the devices work.

              Ken



              --- In combat-l@yahoogroups.com, "henning.forbech" <hf@...> wrote:
              >
              > If you read the proposals for new combat rules you will find both a
              3
              > second AND a 5 second rule.
              > (http://groups.yahoo.com/group/combat-l/files/clprprule1107.doc)
              >
              > The 3 second rule:
              > "Demonstration of the engine shut-off device may be required by the
              > judges before each heat. The engine shut-off device must stop the
              > engine within 3 seconds of activation. Additional demonstrations
              may
              > be requested by the judges after the heat"
              >
              > The 5 second rule:
              > "In the event of a flyaway where the engine shut-off device does
              not
              > stop the engine within 5 seconds"
              >
              > This discussion on the activation time is not new.
              > One year back Doc Jackson made the first proposal for mandatory
              shut-
              > off in combat and he used a 2 second rule. Back then I made an
              > alternative proposal with the 3 and 5 second rules.
              >
              > /Henning Forbech
              >
              >
              >
              >
              > PS: Here is some of the old background information to 3 and 5
              second
              > rules:
              >
              > Section 4.4.6: Controls - Technical Verification:
              > "In the demonstration the shutoff must stop the engine within 3
              > seconds of activation."
              > Last year I did some experiments with a simple spring system that
              > shuts off the fuel supply by squishing the fuel line. The engine
              > stopped after approximately 1.9 seconds which is very close to the
              2
              > seconds proposed by Laird Jackson.
              > A 2 second limit might lead to discussions on how to measure the
              > response time in the demonstration. When has the engine actual
              > stopped? When the engine is not making any combustion any more,
              when
              > it is not turning over anymore or when the propeller comes to a
              > complete stand still?
              > With a shutoff system that stops the fuel supply a combat engine
              will
              > normally stop working after 1.5 seconds and will typically come to
              a
              > complete stand still after 2.5 seconds. Therefore a 3 seconds limit
              > seems more suitable for practical use.
              > You will find a video clip with the test here:
              > http://www.modelflyvning.dk/f2d.htm
              >
              > Section 4.4.15: Cancellation of the Flight:
              > "In the event of a flyaway the pilot shall be disqualified if the
              > shutoff device does not stop the engine within 5 seconds."
              > In this situation the time limit is set a little higher than during
              > the demonstration.
              > The idea is to let the technical verification ensure that the
              shutoff
              > system is capable of bringing the engine to a fast stop. In the
              event
              > of a flyaway it should then only be necessary to observe if the
              > shutoff system is working or not.
              > During a flyaway it will be very difficult to measure the exact
              > reaction time for the shutoff system. The time keepers will
              typically
              > be seeing the midair collision but hearing the engines stopping.
              > The distances involved are far too big for a visible observation of
              > the propeller movement, so the time keepers must rely on the sound
              of
              > the engines.
              > In a situation where a model is flying away from the timekeepers
              the
              > delay of the sound can be as much as 0.35 seconds!
              > (distance across the circle: 35 m, model flying 2 seconds at 42
              m/s,
              > speed of sound: 344 m/s)
              > By setting the time limit for the flyaway situation higher than the
              > test situation, we can eliminate a lot of discussion on how the
              time
              > measurement was done during the flyaway, but we will still be able
              to
              > disqualify a pilot with a non-working shutoff.
              >
              >
              > For more information visit:
              > http://www.modelflyvning.dk/f2d.htm - look for: "Early proposals
              for
              > shut-off rules:"
              >
              > or find it here:
              > http://www.modelflyvning.dk/linestyring/combat/shutoff/docs/Forbech
              > comments.pdf
              >
            • bmears9413@aol.com
              Me and Andy and Larry flew lots of combat matches yesterday. I flew with my shutoff all day and didnt have any malfunctions. One flight the plane rolled in on
              Message 6 of 8 , Nov 19, 2007
                Me and Andy and Larry flew lots of combat matches yesterday. I flew with my shutoff all day and didnt have any malfunctions. One flight the plane rolled in on me and started shutting down. When it hit back on the end of the lines it lit right back up. I have also built two more totally different shutoffs. Ill try and get some pics on here soon. One takes the movement of both lines from the top down, the other uses both lines and holds them together, then uses the "spread" for the action. Another idea not yeat explored is the dump....not from the tubing side, but from the butt end of the blader. If you were to "pop the plug" out of the end of the bladder I think it would shut down in less than two seconds.

                Bob Mears


                -----Original Message-----
                From: kb1_us <kb1_us@...>
                To: combat-l@yahoogroups.com
                Sent: Mon, 19 Nov 2007 9:21 am
                Subject: [combat-l] Re: 3 second shut down problem...........






                we are required to demonstrate the shut-off prior to a match being
                flown here. It's a good way to warm up the engine for the instant
                starts required in our s/l event as well as fast. There have been
                shut-off's that do not pass the test mostly because of poor
                maintenance.It's a good way to be sure the devices work.

                Ken

                --- In combat-l@yahoogroups.com, "henning.forbech" <hf@...> wrote:
                >
                > If you read the proposals for new combat rules you will find both a
                3
                > second AND a 5 second rule.
                > (http://groups.yahoo.com/group/combat-l/files/clprprule1107.doc)
                >
                > The 3 second rule:
                > "Demonstration of the engine shut-off device may be required by the
                > judges before each heat. The engine shut-off device must stop the
                > engine within 3 seconds of activation. Additional demonstrations
                may
                > be requested by the judges after the heat"
                >
                > The 5 second rule:
                > "In the event of a flyaway where the engine shut-off device does
                not
                > stop the engine within 5 seconds"
                >
                > This discussion on the activation time is not new.
                > One year back Doc Jackson made the first proposal for mandatory
                shut-
                > off in combat and he used a 2 second rule. Back then I made an
                > alternative proposal with the 3 and 5 second rules.
                >
                > /Henning Forbech
                >
                >
                >
                >
                > PS: Here is some of the old background information to 3 and 5
                second
                > rules:
                >
                > Section 4.4.6: Controls - Technical Verification:
                > "In the demonstration the shutoff must stop the engine within 3
                > seconds of activation."
                > Last year I did some experiments with a simple spring system that
                > shuts off the fuel supply by squishing the fuel line. The engine
                > stopped after approximately 1.9 seconds which is very close to the
                2
                > seconds proposed by Laird Jackson.
                > A 2 second limit might lead to discussions on how to measure the
                > response time in the demonstration. When has the engine actual
                > stopped? When the engine is not making any combustion any more,
                when
                > it is not turning over anymore or when the propeller comes to a
                > complete stand still?
                > With a shutoff system that stops the fuel supply a combat engine
                will
                > normally stop working after 1.5 seconds and will typically come to
                a
                > complete stand still after 2.5 seconds. Therefore a 3 seconds limit
                > seems more suitable for practical use.
                > You will find a video clip with the test here:
                > http://www.modelflyvning.dk/f2d.htm
                >
                > Section 4.4.15: Cancellation of the Flight:
                > "In the event of a flyaway the pilot shall be disqualified if the
                > shutoff device does not stop the engine within 5 seconds."
                > In this situation the time limit is set a little higher than during
                > the demonstration.
                > The idea is to let the technical verification ensure that the
                shutoff
                > system is capable of bringing the engine to a fast stop. In the
                event
                > of a flyaway it should then only be necessary to observe if the
                > shutoff system is working or not.
                > During a flyaway it will be very difficult to measure the exact
                > reaction time for the shutoff system. The time keepers will
                typically
                > be seeing the midair collision but hearing the engines stopping.
                > The distances involved are far too big for a visible observation of
                > the propeller movement, so the time keepers must rely on the sound
                of
                > the engines.
                > In a situation where a model is flying away from the timekeepers
                the
                > delay of the sound can be as much as 0.35 seconds!
                > (distance across the circle: 35 m, model flying 2 seconds at 42
                m/s,
                > speed of sound: 344 m/s)
                > By setting the time limit for the flyaway situation higher than the
                > test situation, we can eliminate a lot of discussion on how the
                time
                > measurement was done during the flyaway, but we will still be able
                to
                > disqualify a pilot with a non-working shutoff.
                >
                >
                > For more information visit:
                > http://www.modelflyvning.dk/f2d.htm - look for: "Early proposals
                for
                > shut-off rules:"
                >
                > or find it here:
                > http://www.modelflyvning.dk/linestyring/combat/shutoff/docs/Forbech
                > comments.pdf
                >





                ________________________________________________________________________
                Email and AIM finally together. You've gotta check out free AOL Mail! - http://mail.aol.com


                [Non-text portions of this message have been removed]
              • kb1_us
                The dump has been explored.....it works something like this. POP! and then the wing fills up with fuel......engine stops...... would like to see the pic s of
                Message 7 of 8 , Nov 19, 2007
                  The dump has been explored.....it works something like this.

                  "POP!"

                  and then the wing fills up with fuel......engine stops......

                  would like to see the pic's of your new shut-off's I'm trying a
                  similar one using a cable....the more I work on it, the more I like
                  your's.....





                  --- In combat-l@yahoogroups.com, bmears9413@... wrote:
                  >
                  > Me and Andy and Larry flew lots of combat matches yesterday. I flew
                  with my shutoff all day and didnt have any malfunctions. One flight
                  the plane rolled in on me and started shutting down. When it hit back
                  on the end of the lines it lit right back up. I have also built two
                  more totally different shutoffs. Ill try and get some pics on here
                  soon. One takes the movement of both lines from the top down, the
                  other uses both lines and holds them together, then uses the "spread"
                  for the action. Another idea not yeat explored is the dump....not
                  from the tubing side, but from the butt end of the blader. If you
                  were to "pop the plug" out of the end of the bladder I think it would
                  shut down in less than two seconds.
                  >
                  > Bob Mears
                  >
                  >
                  > -----Original Message-----
                  > From: kb1_us <kb1_us@...>
                  > To: combat-l@yahoogroups.com
                  > Sent: Mon, 19 Nov 2007 9:21 am
                  > Subject: [combat-l] Re: 3 second shut down problem...........
                  >
                  >
                  >
                  >
                  >
                  >
                  > we are required to demonstrate the shut-off prior to a match being
                  > flown here. It's a good way to warm up the engine for the instant
                  > starts required in our s/l event as well as fast. There have been
                  > shut-off's that do not pass the test mostly because of poor
                  > maintenance.It's a good way to be sure the devices work.
                  >
                  > Ken
                  >
                  > --- In combat-l@yahoogroups.com, "henning.forbech" <hf@> wrote:
                  > >
                  > > If you read the proposals for new combat rules you will find both
                  a
                  > 3
                  > > second AND a 5 second rule.
                  > > (http://groups.yahoo.com/group/combat-l/files/clprprule1107.doc)
                  > >
                  > > The 3 second rule:
                  > > "Demonstration of the engine shut-off device may be required by
                  the
                  > > judges before each heat. The engine shut-off device must stop the
                  > > engine within 3 seconds of activation. Additional demonstrations
                  > may
                  > > be requested by the judges after the heat"
                  > >
                  > > The 5 second rule:
                  > > "In the event of a flyaway where the engine shut-off device does
                  > not
                  > > stop the engine within 5 seconds"
                  > >
                  > > This discussion on the activation time is not new.
                  > > One year back Doc Jackson made the first proposal for mandatory
                  > shut-
                  > > off in combat and he used a 2 second rule. Back then I made an
                  > > alternative proposal with the 3 and 5 second rules.
                  > >
                  > > /Henning Forbech
                  > >
                  > >
                  > >
                  > >
                  > > PS: Here is some of the old background information to 3 and 5
                  > second
                  > > rules:
                  > >
                  > > Section 4.4.6: Controls - Technical Verification:
                  > > "In the demonstration the shutoff must stop the engine within 3
                  > > seconds of activation."
                  > > Last year I did some experiments with a simple spring system that
                  > > shuts off the fuel supply by squishing the fuel line. The engine
                  > > stopped after approximately 1.9 seconds which is very close to
                  the
                  > 2
                  > > seconds proposed by Laird Jackson.
                  > > A 2 second limit might lead to discussions on how to measure the
                  > > response time in the demonstration. When has the engine actual
                  > > stopped? When the engine is not making any combustion any more,
                  > when
                  > > it is not turning over anymore or when the propeller comes to a
                  > > complete stand still?
                  > > With a shutoff system that stops the fuel supply a combat engine
                  > will
                  > > normally stop working after 1.5 seconds and will typically come
                  to
                  > a
                  > > complete stand still after 2.5 seconds. Therefore a 3 seconds
                  limit
                  > > seems more suitable for practical use.
                  > > You will find a video clip with the test here:
                  > > http://www.modelflyvning.dk/f2d.htm
                  > >
                  > > Section 4.4.15: Cancellation of the Flight:
                  > > "In the event of a flyaway the pilot shall be disqualified if the
                  > > shutoff device does not stop the engine within 5 seconds."
                  > > In this situation the time limit is set a little higher than
                  during
                  > > the demonstration.
                  > > The idea is to let the technical verification ensure that the
                  > shutoff
                  > > system is capable of bringing the engine to a fast stop. In the
                  > event
                  > > of a flyaway it should then only be necessary to observe if the
                  > > shutoff system is working or not.
                  > > During a flyaway it will be very difficult to measure the exact
                  > > reaction time for the shutoff system. The time keepers will
                  > typically
                  > > be seeing the midair collision but hearing the engines stopping.
                  > > The distances involved are far too big for a visible observation
                  of
                  > > the propeller movement, so the time keepers must rely on the
                  sound
                  > of
                  > > the engines.
                  > > In a situation where a model is flying away from the timekeepers
                  > the
                  > > delay of the sound can be as much as 0.35 seconds!
                  > > (distance across the circle: 35 m, model flying 2 seconds at 42
                  > m/s,
                  > > speed of sound: 344 m/s)
                  > > By setting the time limit for the flyaway situation higher than
                  the
                  > > test situation, we can eliminate a lot of discussion on how the
                  > time
                  > > measurement was done during the flyaway, but we will still be
                  able
                  > to
                  > > disqualify a pilot with a non-working shutoff.
                  > >
                  > >
                  > > For more information visit:
                  > > http://www.modelflyvning.dk/f2d.htm - look for: "Early proposals
                  > for
                  > > shut-off rules:"
                  > >
                  > > or find it here:
                  > >
                  http://www.modelflyvning.dk/linestyring/combat/shutoff/docs/Forbech
                  > > comments.pdf
                  > >
                  >
                  >
                  >
                  >
                  >
                  >
                  ______________________________________________________________________
                  __
                  > Email and AIM finally together. You've gotta check out free AOL
                  Mail! - http://mail.aol.com
                  >
                  >
                  > [Non-text portions of this message have been removed]
                  >
                • bmears9413@aol.com
                  I was kinda thinking you have the bladder end sticking out the bottom....or at least a large drain hole. The planes just never seem to be the same after you
                  Message 8 of 8 , Nov 19, 2007
                    I was kinda thinking you have the bladder end sticking out the bottom....or at least a large drain hole. The planes just never seem to be the same after you fill the wing up....

                    Bob Mears


                    -----Original Message-----
                    From: kb1_us <kb1_us@...>
                    To: combat-l@yahoogroups.com
                    Sent: Mon, 19 Nov 2007 11:38 am
                    Subject: [combat-l] Re: 3 second shut down problem...........






                    The dump has been explored.....it works something like this.

                    "POP!"

                    and then the wing fills up with fuel......engine stops......

                    would like to see the pic's of your new shut-off's I'm trying a
                    similar one using a cable....the more I work on it, the more I like
                    your's.....

                    --- In combat-l@yahoogroups.com, bmears9413@... wrote:
                    >
                    > Me and Andy and Larry flew lots of combat matches yesterday. I flew
                    with my shutoff all day and didnt have any malfunctions. One flight
                    the plane rolled in on me and started shutting down. When it hit back
                    on the end of the lines it lit right back up. I have also built two
                    more totally different shutoffs. Ill try and get some pics on here
                    soon. One takes the movement of both lines from the top down, the
                    other uses both lines and holds them together, then uses the "spread"
                    for the action. Another idea not yeat explored is the dump....not
                    from the tubing side, but from the butt end of the blader. If you
                    were to "pop the plug" out of the end of the bladder I think it would
                    shut down in less than two seconds.
                    >
                    > Bob Mears
                    >
                    >
                    > -----Original Message-----
                    > From: kb1_us <kb1_us@...>
                    > To: combat-l@yahoogroups.com
                    > Sent: Mon, 19 Nov 2007 9:21 am
                    > Subject: [combat-l] Re: 3 second shut down problem...........
                    >
                    >
                    >
                    >
                    >
                    >
                    > we are required to demonstrate the shut-off prior to a match being
                    > flown here. It's a good way to warm up the engine for the instant
                    > starts required in our s/l event as well as fast. There have been
                    > shut-off's that do not pass the test mostly because of poor
                    > maintenance.It's a good way to be sure the devices work.
                    >
                    > Ken
                    >
                    > --- In combat-l@yahoogroups.com, "henning.forbech" <hf@> wrote:
                    > >
                    > > If you read the proposals for new combat rules you will find both
                    a
                    > 3
                    > > second AND a 5 second rule.
                    > > (http://groups.yahoo.com/group/combat-l/files/clprprule1107.doc)
                    > >
                    > > The 3 second rule:
                    > > "Demonstration of the engine shut-off device may be required by
                    the
                    > > judges before each heat. The engine shut-off device must stop the
                    > > engine within 3 seconds of activation. Additional demonstrations
                    > may
                    > > be requested by the judges after the heat"
                    > >
                    > > The 5 second rule:
                    > > "In the event of a flyaway where the engine shut-off device does
                    > not
                    > > stop the engine within 5 seconds"
                    > >
                    > > This discussion on the activation time is not new.
                    > > One year back Doc Jackson made the first proposal for mandatory
                    > shut-
                    > > off in combat and he used a 2 second rule. Back then I made an
                    > > alternative proposal with the 3 and 5 second rules.
                    > >
                    > > /Henning Forbech
                    > >
                    > >
                    > >
                    > >
                    > > PS: Here is some of the old background information to 3 and 5
                    > second
                    > > rules:
                    > >
                    > > Section 4.4.6: Controls - Technical Verification:
                    > > "In the demonstration the shutoff must stop the engine within 3
                    > > seconds of activation."
                    > > Last year I did some experiments with a simple spring system that
                    > > shuts off the fuel supply by squishing the fuel line. The engine
                    > > stopped after approximately 1.9 seconds which is very close to
                    the
                    > 2
                    > > seconds proposed by Laird Jackson.
                    > > A 2 second limit might lead to discussions on how to measure the
                    > > response time in the demonstration. When has the engine actual
                    > > stopped? When the engine is not making any combustion any more,
                    > when
                    > > it is not turning over anymore or when the propeller comes to a
                    > > complete stand still?
                    > > With a shutoff system that stops the fuel supply a combat engine
                    > will
                    > > normally stop working after 1.5 seconds and will typically come
                    to
                    > a
                    > > complete stand still after 2.5 seconds. Therefore a 3 seconds
                    limit
                    > > seems more suitable for practical use.
                    > > You will find a video clip with the test here:
                    > > http://www.modelflyvning.dk/f2d.htm
                    > >
                    > > Section 4.4.15: Cancellation of the Flight:
                    > > "In the event of a flyaway the pilot shall be disqualified if the
                    > > shutoff device does not stop the engine within 5 seconds."
                    > > In this situation the time limit is set a little higher than
                    during
                    > > the demonstration.
                    > > The idea is to let the technical verification ensure that the
                    > shutoff
                    > > system is capable of bringing the engine to a fast stop. In the
                    > event
                    > > of a flyaway it should then only be necessary to observe if the
                    > > shutoff system is working or not.
                    > > During a flyaway it will be very difficult to measure the exact
                    > > reaction time for the shutoff system. The time keepers will
                    > typically
                    > > be seeing the midair collision but hearing the engines stopping.
                    > > The distances involved are far too big for a visible observation
                    of
                    > > the propeller movement, so the time keepers must rely on the
                    sound
                    > of
                    > > the engines.
                    > > In a situation where a model is flying away from the timekeepers
                    > the
                    > > delay of the sound can be as much as 0.35 seconds!
                    > > (distance across the circle: 35 m, model flying 2 seconds at 42
                    > m/s,
                    > > speed of sound: 344 m/s)
                    > > By setting the time limit for the flyaway situation higher than
                    the
                    > > test situation, we can eliminate a lot of discussion on how the
                    > time
                    > > measurement was done during the flyaway, but we will still be
                    able
                    > to
                    > > disqualify a pilot with a non-working shutoff.
                    > >
                    > >
                    > > For more information visit:
                    > > http://www.modelflyvning.dk/f2d.htm - look for: "Early proposals
                    > for
                    > > shut-off rules:"
                    > >
                    > > or find it here:
                    > >
                    http://www.modelflyvning.dk/linestyring/combat/shutoff/docs/Forbech
                    > > comments.pdf
                    > >
                    >
                    >
                    >
                    >
                    >
                    >
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