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  • Jean-Yves Renaud
    If there is cavitation in my pop-pop engines, it is marginal because I don t see any trace of metallic powder in the test tank. Even if it is loud enough to be
    Message 1 of 20 , Oct 23, 2007
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      If there is cavitation in my pop-pop engines, it is marginal because I don't see any trace of metallic powder in the test tank. Even if it is loud enough to be heard, the power is relatively weak.

      I have some experience with cavitation. Just an anecdote. I remember a full power test on a fast ship (2500 tons at 30 knots). After something like 8 hours at full speed (only 8 hours!)  there were big holes at the propeller boss. In each hole I could put my whole hand (closed). 


      --- In pop-pop-steamboats@yahoogroups.com, "David Halfpenny" <dh1@...> wrote:
      >
      > ----- Original Message -----
      > From: "Jean-Yves Renaud" boite.de.j-y@...
      >
      > > you could hear the . . . "cliks" of collapsing bubbles
      >
      > Cavitation problems?
      >
      > If the boiler is removable, it might be as well to weigh it from time to
      > time to see if it is getting thinner.
      >
      > David 1/2d
      >

    • Jean-Yves Renaud
      Hi Pete. I could be wrong for some purists, but for several reasons I call all these engines (with or without diaphragm) pop-pop engines. 1st: I don t know
      Message 2 of 20 , Oct 23, 2007
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        Hi Pete.

        I could be wrong for some purists, but for several reasons I call all these engines (with or without diaphragm) "pop-pop" engines.

        1st: I don't know another easy wording to call them.

        2nd: Whatever the size and the type of the engine there is a pressure variation which is the basic definition of a sound.

        3rd: If you put a mike into the water and connect it to an oscilloscope you could "see" the sound of any pop-pop engine (coil, drum, diaphragm...)

        English is not my mother language. If you have another generic name for the whole "pop-pop" family I'm ready to use it.

        Coming to the steam engine of the home page image, it is not a pop-pop engine. And there is no reason for it to be of the diaphragm type. (It could be, but it would be useless because there is no periodic pressure variation). Therefore, it can be strongly welded (not with soft metal) and this would allow it to work until there is no more water into the drum. Jeff Bindon's famous steamcar works like that. It stops (without destruction) when there is no fuel or no water; whichever condition comes first.

        The door knob engine works, but I didn't test it on a hull. Very seldom I used a hull to check my pop-pop engines. My main concern (today) is the engine itself.  When I'm satisfied of an engine I'll look for a hull...

        Jean-Yves


        --- In pop-pop-steamboats@yahoogroups.com, "Pete B." <georgeyyy@...> wrote:
        >
        >
        > Hi Jean-Yves & group,
        >
        > Thanks for you explanation of a true pop-pop engine and the steamer.
        > From this explanation would you consider the diaphragm engine the only
        > true pop-pop? Is Dave Noyes's barrel engine a variation of this design?
        > His doesn't use the venturi effect. Before your explanation I thought
        > that the two differ Ø tubes were so that the boiler could be
        > removed for filling. I missed the venturi effect defined by the "drawn
        > air".
        >
        > I had picked up on the difference between this home page "steamer and
        > pop-pops. Apparently the author did also. In the title he wrote
        > (POP-POP?). I had hoped to stir up some comments...and did! Please keep
        > them coming.
        >
        > It looks like this steamer engine is closed loop as it doesn't have an
        > inlet. Does the capacity of this boiler have to been matched with the
        > capacity of the fuel supply to prevent damage? I think that Dave
        > Halfpenny was implying this with his resonse on wall degradation. It
        > seems that you would want the fuel to run out before the water in the
        > boiler. In the coil tube boiler with an inlet and an outlet the travel
        > of the boat would be limited by the fuel supply as possible burn out
        > wouldn't be as much of an issue.
        >
        > Your door knob engine looks like a piece of artwork. Like Xavier I would
        > like to know how it works. Do you have a boat for an installation or do
        > you have to design around the door knob?
        >
        > Pete
        > --- In pop-pop-steamboats@yahoogroups.com, "Jean-Yves Renaud"
        > boite.de.j-y@ wrote:
        > >
        > >
        > > It is not a pop-pop boat. It is a steamer. The boiler delivers a steam
        > > flow which is amplified by carrying air (Venturi effect). And it is
        > the
        > > mixture steam/air which propels the boat.
        > >
        > > The efficiency and the speed of such a boat can be quite better than
        > the
        > > one of a pop-pop boat...but there is no pop-pop sound.
        > >
        > > Jean-Yves
        > >
        > >
        > > --- In pop-pop-steamboats@yahoogroups.com, "Pete B." georgeyyy@
        > > wrote:
        > > >
        > > >
        > > > The new home page image is taken from:
        > > >
        > > > From The Boy Mechanic (1913)
        > > > A Model Steam (Pop-Pop?) Boat
        > > >
        > > > Send in your pop-pop related images/messages we'd love to see what
        > > your
        > > > doing with your projects; engine and boat design or anything even
        > > > slightly related.
        > > >
        > > > Pete
        > > >
        > >
        >

      • David Halfpenny
        ... From: Jean-Yves Renaud ... don t see any trace of metallic powder in the test tank. Even if it is loud enough to be heard, the
        Message 3 of 20 , Oct 23, 2007
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          ----- Original Message -----
          From: "Jean-Yves Renaud" <boite.de.j-y@...>

          > If there is cavitation in my pop-pop engines, it is marginal because I
          don't see any trace of metallic powder in the test tank. Even if it is
          loud enough to be heard, the power is relatively weak.

          > I have some experience with cavitation. Just an anecdote. I remember a
          full power test on a fast ship (2500 tons at 30 knots). After something
          like 8 hours at full speed (only 8 hours!) there were big holes at the
          propeller boss. In each hole I could put my whole hand (closed).

          My experience was with hydrodynamic brakes on trains.
          Basically the brake was a "fluid flywheel" coupling on the axle. When we
          filled it with liquid, the spiral motion of the fluid between the vanes
          slowed the train very effectively from high to low speed, then friction
          brakes took over to stop it. The vane discs of the brake were made of
          manganese bronze which is resistant to cavitation and used for propellers.
          They looked a bit like this:
          http://www.railcar.co.uk/pics/tech/engines/fluidflywheel/cutaway.jpg

          One day I was on a test train and my staff asked me to listen to a strange
          rumbling sound from the floor. I guessed that a brake disc had broken up.
          When we opened it up, we found the impeller disc completely gone, and in
          its place was a heap of beautifully rounded gleaming golden pebbles.

          The problem was the inertia of the heavy rotors, and we solved it by
          substituting aluminium bronze, which is much lighter.

          David 1/2d
          British Railways design engineer
        • David Halfpenny
          ... From: Jean-Yves Renaud ... these engines (with or without diaphragm) pop-pop engines. 1st: I don t know another easy wording
          Message 4 of 20 , Oct 23, 2007
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            ----- Original Message -----
            From: "Jean-Yves Renaud" <boite.de.j-y@...>

            > I call all
            these engines (with or without diaphragm) "pop-pop" engines.

            1st: I don't know another easy wording to call them.

            Pulse engine?

            Pulse-jet engine?

            The internal combustion version is often called a Pulse Jet engine.
            They have a flap valve rather than a diaphragm, and you certainly don't
            need a microphone to hear them coming!

            Hey look at this US Patent application under that name - look familiar?
            http://www.freepatentsonline.com/4057961.html
            Bet that poor sucker has paid his agent a lot of money to get thus far.

            See you in court guys!

            By the way, did you know that there's a rotary version of the pulse engine,
            using air rather than steam as the working fluid?

            David 1/2d
          • Xavier LUCAS
            Quelqu un parle du Charles de Gaulle ? Bon d accord mauvaise plaisanterie, pas le même chantier naval, beaucoup plus lourd et un peu moins rapide désolé...
            Message 5 of 20 , Oct 23, 2007
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              Quelqu'un parle du Charles de Gaulle ? Bon d'accord mauvaise
              plaisanterie, pas le même chantier naval, beaucoup plus lourd et un
              peu moins rapide désolé...


              --- In pop-pop-steamboats@yahoogroups.com, "Jean-Yves Renaud"
              <boite.de.j-y@...> wrote:
              >
              >
              > If there is cavitation in my pop-pop engines, it is marginal because I
              > don't see any trace of metallic powder in the test tank. Even if it is
              > loud enough to be heard, the power is relatively weak.
              >
              > I have some experience with cavitation. Just an anecdote. I remember a
              > full power test on a fast ship (2500 tons at 30 knots). After something
              > like 8 hours at full speed (only 8 hours!) there were big holes at the
              > propeller boss. In each hole I could put my whole hand (closed).
              >
              >
              > --- In pop-pop-steamboats@yahoogroups.com, "David Halfpenny" <dh1@>
              > wrote:
              > >
              > > ----- Original Message -----
              > > From: "Jean-Yves Renaud" boite.de.j-y@
              > >
              > > > you could hear the . . . "cliks" of collapsing bubbles
              > >
              > > Cavitation problems?
              > >
              > > If the boiler is removable, it might be as well to weigh it from time
              > to
              > > time to see if it is getting thinner.
              > >
              > > David 1/2d
              > >
              >
            • David Halfpenny
              ... From: Xavier LUCAS Quelqu un parle du Charles de Gaulle ? Bon d accord mauvaise plaisanterie, pas le même chantier naval, beaucoup
              Message 6 of 20 , Oct 23, 2007
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                ----- Original Message -----
                From: "Xavier LUCAS" <lucas.xav@...>


                Quelqu'un parle du Charles de Gaulle ? Bon d'accord mauvaise
                plaisanterie, pas le même chantier naval, beaucoup plus lourd et un
                peu moins rapide désolé...

                Êtes-vous parler le Français au cas les espions Anglais écouteraient -
                encore une fois ? ;-)

                Davide Demi-Sous
              • Jean-Yves Renaud
                ... prime mover, including the electric engine of Pr Le Bot described in Model Engineer (in May?). ... V2...) and you certainly don t ... familiar? ... far.
                Message 7 of 20 , Oct 23, 2007
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                  --- In pop-pop-steamboats@yahoogroups.com, "David Halfpenny" <dh1@...> wrote:
                  >
                  > ----- Original Message -----
                  > From: "Jean-Yves Renaud" boite.de.j-y@...
                  >
                  > > I call all
                  > these engines (with or without diaphragm) "pop-pop" engines.
                  >
                  > 1st: I don't know another easy wording to call them.
                  >
                  > Pulse engine?
                  >
                  > Pulse-jet engine? Pulse engine or pulse-jet engine include many other prime mover, including the electric engine of Pr Le Bot described in Model Engineer (in May?).
                  >
                  > The internal combustion version is often called a Pulse Jet engine.
                  > They have a flap valve rather than a diaphragm, (The famous V1 or V2...)
                  and you certainly don't
                  > need a microphone to hear them coming! >
                  > Hey look at this US Patent application under that name - look familiar?
                  > http://www.freepatentsonline.com/4057961.html
                  > Bet that poor sucker has paid his agent a lot of money to get thus far. This patent is the description of Piot invention patented in 1891. What is new?
                  >
                  > See you in court guys!
                  >
                  > By the way, did you know that there's a rotary version of the pulse engine,
                  > using air rather than steam as the working fluid? No. Where can we see a drawing of the principle?

                  Jean-Yves

                • Xavier LUCAS
                  To be honest David, I am not sure that you guys in england and in the us know all that happend to this ship during his first trial at sea... that why I was
                  Message 8 of 20 , Oct 23, 2007
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                    To be honest David, I am not sure that you guys in england and in the
                    us know all that happend to this ship during his first trial at sea...
                    that why I was writting in french.

                    Xavier

                    --- In pop-pop-steamboats@yahoogroups.com, "David Halfpenny" <dh1@...>
                    wrote:
                    >
                    >
                    > ----- Original Message -----
                    > From: "Xavier LUCAS" <lucas.xav@...>
                    >
                    >
                    > Quelqu'un parle du Charles de Gaulle ? Bon d'accord mauvaise
                    > plaisanterie, pas le même chantier naval, beaucoup plus lourd et un
                    > peu moins rapide désolé...
                    >
                    > Êtes-vous parler le Français au cas les espions Anglais écouteraient -
                    > encore une fois ? ;-)
                    >
                    > Davide Demi-Sous
                    >
                  • David Halfpenny
                    ... From: Xavier LUCAS
                    Message 9 of 20 , Oct 24, 2007
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                      ----- Original Message -----
                      From: "Xavier LUCAS" <lucas.xav@...

                      > To be honest David, I am not sure that you guys in england and in the
                      us know all that happend to this ship during his first trial at sea...
                      that why I was writting in french.

                      I'm sure that I don't know the half of it.
                      I just remember the disappointing propeller trouble and maintenance issues
                      since.

                      But somebody here will know: as I recall a party of British agents got
                      thrown off for making unauthorised inspections of the nuclear plant. Oops!
                      And we have an Anglo-French deal to build the next big European carrier as
                      a joint venture of some kind.

                      Alors, ve meet again, Meester Bond . . . .

                      David 1/2d

                      Charles de Gaulle is the spectacular aircraft carrier supporting French
                      forces in Afghanistan.
                    • Xavier LUCAS
                      Propeller trouble ? Well they just lost one in the carribean sea...a few years ago during the sea trial, then replace it with the propeller from another
                      Message 10 of 20 , Oct 24, 2007
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                        Propeller trouble ?

                        Well they just lost one in the carribean sea...a few years ago during
                        the sea trial, then replace it with the propeller from another
                        aircraft carrier. ANd they are actually replacing it during a major
                        refit something like ten years after...



                        --- In pop-pop-steamboats@yahoogroups.com, "David Halfpenny" <dh1@...>
                        wrote:
                        >
                        > ----- Original Message -----
                        > From: "Xavier LUCAS" <lucas.xav@...
                        >
                        > > To be honest David, I am not sure that you guys in england and in the
                        > us know all that happend to this ship during his first trial at sea...
                        > that why I was writting in french.
                        >
                        > I'm sure that I don't know the half of it.
                        > I just remember the disappointing propeller trouble and maintenance
                        issues
                        > since.
                        >
                        > But somebody here will know: as I recall a party of British agents got
                        > thrown off for making unauthorised inspections of the nuclear plant.
                        Oops!
                        > And we have an Anglo-French deal to build the next big European
                        carrier as
                        > a joint venture of some kind.
                        >
                        > Alors, ve meet again, Meester Bond . . . .
                        >
                        > David 1/2d
                        >
                        > Charles de Gaulle is the spectacular aircraft carrier supporting French
                        > forces in Afghanistan.
                        >
                      • Pete
                        Hey Frank, Thanks for the PR. The engine project is going well after a little bump in the road. We re going to have a public demo of the prototype on Oct 10th
                        Message 11 of 20 , Sep 30, 2009
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                          Hey Frank,

                          Thanks for the PR. The engine project is going well after a little bump in the road. We're going to have a public demo of the prototype on Oct 10th at the Clermont Historic Site. They asked if I would do a 1/2 presentation and field questions afterwards. Although I hate public speaking I agreed. Yesterday I got word that I am getting a $300 stipend for the presentation. I am putting it all into the projects acct.

                          Beside the original 5 volunteers who have donated their tie and material we have received support in the for of services, material and product from 9 companies. I believe that a company in the netherlands is making partss for me. I haven't rec'd confirmation but I was asked what material I needed the parts made in.

                          The Fulton Engine project has been extremely rewarding in many aspects. All of the support has been a pleasant surprise.
                        • Pete
                          A follow up to the support....3 new pictures uploaded th the Fulton s Followers folder. All of the milled spokes and crescents were delivered to me at work.
                          Message 12 of 20 , Sep 30, 2009
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                            A follow up to the support....3 new pictures uploaded th the Fulton's Followers folder.

                            All of the milled spokes and crescents were delivered to me at work. Two local machine shops donated their time to mill the notches that weren't able to do be done with the laser cutting process. the assemblies are comprised of the set-up hub from Florida, 8 spokes and 16 crescent pieces that were laser cut in Massachusetts and milled locally. They all assembled with out the necessity of tweaking. I used the minimum of hardware, just enough to hold the assembly together. It's hard to tell but in the one image I assembled the splice joint with two different approaches. At Approx 12:00 o'clock I assembled the bolt with its head up and no washer. At approximate 3:00 o'clock the bolt is assembled with the head on the far side with a flat washer and nut on the near side. Aesthetically I favor the washer and nut on the far side. The axle clamp (the silver disk)were made in Maryland. They will have the nut and washer on the outside. The test axle was made by a friend here in Woodstock.For reference the dimension across the spokes (end to end) is 15".
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