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

Re: [multimachine] Next prop question

Expand Messages
  • Eggleston Lance
    RE: Kort nozzle http://www.submarineboat.com/kort_nozzles.htm
    Message 1 of 21 , Apr 29, 2013
    • 0 Attachment
      RE:
      Kort nozzle

      http://www.submarineboat.com/kort_nozzles.htm


      On Apr 29, 2013, at 11:14 PM, Eggleston Lance wrote:

      >
      > A Kort nozzle
    • David G. LeVine
      ... John, would it also be wise to consider reinforced composited, like bronze or stainless wool? Dave 8{) -- / Among the many misdeeds of British rule in
      Message 2 of 21 , Apr 30, 2013
      • 0 Attachment
        On 04/29/2013 09:50 PM, Johnny wrote:
        I would suggest that you determine the appropriate pitch, diameter, shaft size, etc, and find a locally available aluminum screw and make a duplicate mold out of silicone, and send it along with casting resin so that the screws could be duplicated hundreds of times, perhaps even creating several boats of this type for this guy's village.
        
        Reynolds casting materials is a good place to start, they're on the Internet and located in Los Angeles, CA.
        
        John W

        John, would it also be wise to consider reinforced composited, like bronze or stainless wool?

        Dave  8{)

        --


        "Among the many misdeeds of British rule in India, history will look upon the Act of depriving a whole nation of arms as the blackest."

        Mohandus Ghandi, An Autobiography, Page 446.
      • greg123452003
        Until we know what the design criteria is, we are all blowing in the wind. What type of boat? What engine type? Needed speed? Needed range? Is scrap aluminum
        Message 3 of 21 , Apr 30, 2013
        • 0 Attachment
          Until we know what the design criteria is, we are all blowing in the wind. What type of boat? What engine type? Needed speed? Needed range? Is scrap aluminum available? Scrap pipe? Angle iron? You can design what you like but if the parts are too expensive or won't fit the available boats, then you're wasting your time - design exercise excluded, and costing the recipient time, money and prestige - a solution that doesn't work is a FAILURE!
        • Pat
          John Thanks for the link to the GREAT Reynolds site. This stuff is all new to me so the learning resources are just what I need. From what little I have read
          Message 4 of 21 , Apr 30, 2013
          • 0 Attachment
            John

            Thanks for the link to the GREAT Reynolds site. This stuff is all new to me so the learning resources are just what I need. From what little I have read so far the problem should be quite solvable.

            I want to get 2 sample 6+" props from Thailand (10 and 100 mph models) and also a drawing or sample of a 150cc motorcycle to longtail adapter. Amazon should deliver a manual for this kind of bike today.

            This is another technology that needs to spread and I am going to stick with it as long as I can but my health is not improving to put it mildly.

            Why do I think it is important? Inexpensive shallow water boats are going to be very important one day soon (I think). And also...Jeremmy needs a way to make a steady income so that he can keep building machines and tools.

            Pat

            --- In multimachine@yahoogroups.com, "Johnny" <firearms_engraving@...> wrote:
            >
            >
            > As I have some experience in casting with resins, I thought I would weigh in here. There have been many successful attempts at resin cast screws (propellers are found on aircraft), with the idea being when one wears out due to contact with objects other than H2O, they can be VERY easily duplicated with the same silicone mold.
            >
            > I would suggest that you determine the appropriate pitch, diameter, shaft size, etc, and find a locally available aluminum screw and make a duplicate mold out of silicone, and send it along with casting resin so that the screws could be duplicated hundreds of times, perhaps even creating several boats of this type for this guy's village.
            >
            > Reynolds casting materials is a good place to start, they're on the Internet and located in Los Angeles, CA.
            >
            > John W
            >
            > --- In multimachine@yahoogroups.com, Eggleston Lance <wheezer606@> wrote:
            > >
            > > Lost foam would require hand cut originals
            > > for each pour. They would be gated and sprued
            > > and coated with a thin shell of plaster/sand
            > > and poured. The shell is destroyed to get the cast.
            > >
            > > If you made a multi-part master plaster mould
            > > of the original, filled it with casting wax, add the gates and sprues,
            > > encased the wax positive in plaster/sand shell,
            > > melt out, then burn out the wax. Now fill with aluminum for the piece.
            > > The master mould survives.
            > >
            > > Make a two part form <box> for sand casting < cope and drag>.
            > > Mix up the sand/clay/water. Let it age.
            > > Place the original, ram sand around it half way up.
            > > Tap and rotate <unscrew> the prop from the sand.
            > > Repeat for the other half.
            > > Cut the Sprue, vents, gates into the sand.
            > > Fasten the cope and drag securely.
            > > Pour.
            > > When you remove the cast, the sand mold is recycled.
            > > Repeat.
            > >
            > > Some one mentioned sand cast with a follower board too.
            > >
            > > 'taint no _easy_ way.
            > >
            > > lance
            > > ++++
            > >
            > > On Apr 28, 2013, at 2:20 PM, Pat wrote:
            > >
            > > > He is interested in lost foam casting so I wonder if a mold could be taken of the sample prop and used to make a bunch of props.
            > >
            >
          • michael broadbent
            Hi Pat,             Trying to send some pictures one shows the mounting boss for power unit ________________________________ From: Pat Delany
            Message 5 of 21 , Apr 30, 2013
            Hi Pat,
                        Trying to send some pictures one shows the mounting boss for power unit

            From: Pat Delany <rigmatch@...>
            To: "multimachine@yahoogroups.com" <multimachine@yahoogroups.com>
            Sent: Tuesday, 30 April 2013, 4:00
            Subject: Re: [multimachine] Re: Next prop question



            Good points all!!

            The prop I am going to try to buy (along with the engine to shaft adapter) is the one Thai boat racers use on their 150cc motorcycle engine, long tail boats. I know the pitch will be wrong but 100mph performance is nothing to sneeze at for a motor this small.

            Pat 

            From: Shannon DeWolfe <sdewolfe@...>
            To: multimachine@yahoogroups.com
            Sent: Monday, April 29, 2013 9:03 PM
            Subject: Re: [multimachine] Re: Next prop question

             
            Pat and all,

            I have read all the posts concerning the motor and prop design for
            Jeremmy to try. This is probably the most ambitious project he could
            possibly tackle. The propeller design is crucial to the success of the plan.

            I know very little about propellers. But I do know a few things about
            engines.

            The 4stroke engine shown in the demo video early-on in this thread has a
            wide flat torque curve and is governed to about 3200 RPM. A 2stroke
            scooter motor rated to the same HP will have a very narrow powerband,
            probably peaking somewhere north of 6000 RPM. The strength of a 2stroke
            is the ability to rev. You can make a lot of HP from a small motor if
            you can spin it very fast. But the trade off is no power down low in the
            RPM range.

            A prop that works on a 5HP 4stroke will not work on a 2stroke rated at
            5HP. The pitch will be too coarse for the scooter motor to overcome. It
            will not get up to speed to utilize the narrow powerband. If the motor
            actually gets to it's powerband, the prop will likely cavitate.

            Will the boat move? Yes. But it will have high fuel consumption and very
            high wear on the motor.

            What I am trying to say is, don't copy a prop used on a 4stroke engine.
            Better to use a prop off of an older 2stroke outboard motor as a
            starting point -- if one can be found. I haven't seen a small 2stroke
            outboard motor in a long time. But, if memory serves, the prop pitch was
            much finer than the prop in the video of the 4stroke on a stick.

            Of course, if Jeremmy has access to 4stroke scooters this post was
            useless. ;-)

            Mr. Shannon DeWolfe
            --I've taken to using Mr. because my name misleads folks on the WWW. I am a 57 year old fat man.

            On 4/29/2013 8:50 PM, Johnny wrote:
            > I would suggest that you determine the appropriate pitch, diameter,
            > shaft size, etc, and find a locally available aluminum screw







          • Johnny
            Hi Dave: I think compositing is a suitable alternative to metal casting, but in many cases, without proper training an neophyte caster would be setting himself
            Message 6 of 21 , Apr 30, 2013
            • 0 Attachment
              Hi Dave:

              I think compositing is a suitable alternative to metal casting, but in many cases, without proper training an neophyte caster would be setting himself up for failure and lots of wasted materials.

              If adding material is the goal, I would recommend a fibrous nonmetallic product such as fiberglass, carbon fibre, or in a worse case scenario, even certain plant fibers (bamboo?) for short term use.

              Even suspending a framework/latticework of common chicken wire could add additional strength without detracting from the necessary flexibility in the application of this sort.

              John W

              --- In multimachine@yahoogroups.com, "David G. LeVine" <dlevine@...> wrote:
              >
              > On 04/29/2013 09:50 PM, Johnny wrote:
              > > I would suggest that you determine the appropriate pitch, diameter, shaft size, etc, and find a locally available aluminum screw and make a duplicate mold out of silicone, and send it along with casting resin so that the screws could be duplicated hundreds of times, perhaps even creating several boats of this type for this guy's village.
              > >
              > > Reynolds casting materials is a good place to start, they're on the Internet and located in Los Angeles, CA.
              > >
              > > John W
              >
              > John, would it also be wise to consider reinforced composited, like
              > bronze or stainless wool?
              >
              > Dave 8{)
              >
              > --
              >
              >
              > /"Among the many misdeeds of British rule in India, history will look
              > upon the Act of depriving a whole nation of arms as the blackest."/
              >
              > Mohandus Ghandi, An Autobiography, Page 446.
              >
            • Pat
              Hi Barge Pis did not get through (thanks Yahoo!!) Please open a photo folder (let us know which one) and try to upload them there. Very anxious to see them, I
              Message 7 of 21 , Apr 30, 2013
              • 0 Attachment
                Hi Barge

                Pis did not get through (thanks Yahoo!!)

                Please open a photo folder (let us know which one) and try to upload them there.

                Very anxious to see them, I got a Chinese 125cc m/c manual today which did not help much except to learn that most are Honda or Suzuki copies and that some are water cooled.

                Pat

                --- In multimachine@yahoogroups.com, michael broadbent <bargemaster24@...> wrote:
                >
                > Hi Pat,
                >             Trying to send some pictures one shows the mounting boss for power unit
                >
                >
                > ________________________________
                > From: Pat Delany <rigmatch@...>
                > To: "multimachine@yahoogroups.com" <multimachine@yahoogroups.com>
                > Sent: Tuesday, 30 April 2013, 4:00
                > Subject: Re: [multimachine] Re: Next prop question
                >
                >
                >
                >
                >
                >
                > Good points all!!
                >
                > The prop I am going to try to buy (along with the engine to shaft adapter) is the one Thai boat racers use on their 150cc motorcycle engine, long tail boats. I know the pitch will be wrong but 100mph performance is nothing to sneeze at for a motor this small.
                >
                > Pat 
                >
                >
                > ________________________________
                > From: Shannon DeWolfe <sdewolfe@...>
                > To: multimachine@yahoogroups.com
                > Sent: Monday, April 29, 2013 9:03 PM
                > Subject: Re: [multimachine] Re: Next prop question
                >
                >
                >
                >  
                > Pat and all,
                >
                > I have read all the posts concerning the motor and prop design for
                > Jeremmy to try. This is probably the most ambitious project he could
                > possibly tackle. The propeller design is crucial to the success of the plan.
                >
                > I know very little about propellers. But I do know a few things about
                > engines.
                >
                > The 4stroke engine shown in the demo video early-on in this thread has a
                > wide flat torque curve and is governed to about 3200 RPM. A 2stroke
                > scooter motor rated to the same HP will have a very narrow powerband,
                > probably peaking somewhere north of 6000 RPM. The strength of a 2stroke
                > is the ability to rev. You can make a lot of HP from a small motor if
                > you can spin it very fast. But the trade off is no power down low in the
                > RPM range.
                >
                > A prop that works on a 5HP 4stroke will not work on a 2stroke rated at
                > 5HP. The pitch will be too coarse for the scooter motor to overcome. It
                > will not get up to speed to utilize the narrow powerband. If the motor
                > actually gets to it's powerband, the prop will likely cavitate.
                >
                > Will the boat move? Yes. But it will have high fuel consumption and very
                > high wear on the motor.
                >
                > What I am trying to say is, don't copy a prop used on a 4stroke engine.
                > Better to use a prop off of an older 2stroke outboard motor as a
                > starting point -- if one can be found. I haven't seen a small 2stroke
                > outboard motor in a long time. But, if memory serves, the prop pitch was
                > much finer than the prop in the video of the 4stroke on a stick.
                >
                > Of course, if Jeremmy has access to 4stroke scooters this post was
                > useless. ;-)
                >
                > Mr. Shannon DeWolfe
                > --I've taken to using Mr. because my name misleads folks on the WWW. I am a 57 year old fat man.
                >
                > On 4/29/2013 8:50 PM, Johnny wrote:
                > > I would suggest that you determine the appropriate pitch, diameter,
                > > shaft size, etc, and find a locally available aluminum screw
                >
              • David G. LeVine
                ... Whatever else you do, USE A HEAT EXCHANGER with a water cooled engine, do not use raw river water. Dave 8{) -- A word to the wise ain t necessary - it s
                Message 8 of 21 , May 1, 2013
                • 0 Attachment
                  On 04/30/2013 10:52 PM, Pat wrote:
                  > Very anxious to see them, I got a Chinese 125cc m/c manual today which did not help much except to learn that most are Honda or Suzuki copies and that some are water cooled.

                  Whatever else you do, USE A HEAT EXCHANGER with a water cooled engine,
                  do not use raw river water.

                  Dave 8{)

                  --

                  "A word to the wise ain't necessary - it's the stupid ones that need the
                  advice."

                  Bill Cosby
                Your message has been successfully submitted and would be delivered to recipients shortly.