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Re: [multimachine] Mike, a big favor [1 Attachment]

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  • HB
    Just provide a mounted jack shaft assembly under the motor base.  One end of the jack shaft, on the same end as the motor output shaft, contains a sprocket
    Message 1 of 9 , May 8 1:25 PM
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      Just provide a mounted jack shaft assembly under the motor base.
       One end of the jack shaft, on the same end as the motor output shaft, contains a sprocket matched to the sprocket on the output shaft of the motor. ( The sprocket ratio would be determined by the motor's most efficient RPM and the selected propeller configuration.. )
      If you have a CCW propeller and a CCW motor, the propeller shaft would be powered by the jack shaft from the same end as the motor output shaft. (also same end where the sprocket is installed on the jack shaft))
      If you have a CW propeller and a CCW motor, the propeller shaft would have to be powered from the other end opposite the sprocket end of the jack shaft. ( the motor output shaft would be oriented toward the forward end of the boat)

      The jack shaft/sprocket system provides two purposes, first to be able to achieve the required rotation for the propeller, and second to be able to have the most efficient propeller and motor rotational speed matching.



      From: michael broadbent <bargemaster24@...>
      To: "multimachine@yahoogroups.com" <multimachine@yahoogroups.com>
      Cc: "BrdbMc@..." <BrdbMc@...>
      Sent: Wednesday, May 8, 2013 11:58 AM
      Subject: Re: [multimachine] Mike, a big favor [1 Attachment]

       
      Hi Pat
                   Just a first attempt to put ideas to paper .I am trying to keep in mind the limitations that exist
      locally.  Any input from  others is all ways  welcome.
       
      Will do more tomorrow
       
      Mike
       

      From: Pat Delany <rigmatch@...>
      To: "multimachine@yahoogroups.com" <multimachine@yahoogroups.com>
      Sent: Wednesday, 8 May 2013, 1:28
      Subject: [multimachine] Mike, a big favor



      Would you try to draw the whole thing (sprocket drive, inner, outer shaft etc.)

      Pat

      From: michael broadbent <bargemaster24@...>
      To: "multimachine@yahoogroups.com" <multimachine@yahoogroups.com>
      Cc: "BrdbMc@..." <BrdbMc@...>
      Sent: Tuesday, May 7, 2013 3:31 PM
      Subject: Re: [multimachine] rotating the engine/Bargemaster [1 Attachment]

       
      Hi  Pat
                  attached is drawing of the simple type of mounting used .2 inch angle is ideal.
      The part marked A is normal fitted to a bored  wooden cross beam although some just bore a snug
      fitting hole and forget the metal insert , No fancy thrust bearings are used  just normal flat washers liberal greased
      The utube clip shows a throttle control but I have noticed a lot use the sprung load twist grip from a motor bike which means the engine can be set to stall if anything happens to the driver,
           Reading some of the posts to day I remembered the shrimp farms in Thailand use a small engine to aerate the water it turns a length of pipe with short cross arms that work like  water wheel in reverse .these engines run all day and night 
      at a constant speed.
        Fingers crossed the attachment works
       
      Mike
      From: Pat Delany <rigmatch@...>
      To: "multimachine@yahoogroups.com" <multimachine@yahoogroups.com>
      Sent: Monday, 6 May 2013, 18:33
      Subject: Re: [multimachine] rotating the engine/Bargemaster



      Really want to see how this is done in practice even though I can think of several neat ways to do it.
      A short chain drive would also handle slight miss-alignment.
      I don't know a thing about the physics of air cooling motors. Would a m/c motor cool at slow speeds?
      A factory trained lawnmower mechanic once told me that much damage was done by mowing with a motor at less than top speed.

      We really need Bargemaster's pics uploaded to our photo section.

      pat

      From: kbs2244 <no_reply@yahoogroups.com>
      To: multimachine@yahoogroups.com
      Sent: Monday, May 6, 2013 11:42 AM
      Subject: [multimachine] rotating the engine

       
      Useing the existing sprocket set p will not only give the ability to change shaft rotation but also shaft RPM just by changing sprocket size.
      This will allow fine tuning to a specific prop configuration.















    • David G. LeVine
      ... Be sure to have guards on the chain, getting stuff caught can be bad, having chain chunks flying at high RPMs can make for an uncomfortable trip. Timing
      Message 2 of 9 , May 9 10:56 AM
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        On 05/08/2013 04:25 PM, HB wrote:
        > The jack shaft/sprocket system provides two purposes, first to be able
        > to achieve the required rotation for the propeller, and second to be
        > able to have the most efficient propeller and motor rotational speed
        > matching.

        Be sure to have guards on the chain, getting stuff caught can be bad,
        having chain chunks flying at high RPMs can make for an uncomfortable trip.

        Timing belts are better (they don't make as much noise, they don't
        require lube, etc.), but the sprockets are harder to get (although for
        1:1, 2:2 AND 1:2 ratios timing gears work well) and they have lower
        losses. Poly-v (aka multi-rib, etc.) are a really good choice (low
        losses, low cost, etc.), but need tensioners and the pulleys must be
        machined (with an MM, it is pretty easy.) Timing belts are used instead
        of timing chains to lower costs and improve efficiency, poly-v belts are
        used for the same reasons. Tensioners are not cheap, but prolong belt
        life, automotive belts should be fine up to about 7 HP, the narrow
        Toyota belts should be good to 3 HP. CV belts are good for 100+ HP with
        long life.

        Dave 8{)

        --

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

        Bill Cosby
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