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  • variable speed transmission?

    If I can't get this treadmill motor and boards to work then I will use a mechanical drive for my welding positioner. So I will need a variable speed transmission.

    I have several gear reduction options already.

    So what would you all suggest for a variable speed drive I could build? One option I thought of was a smaller rubber type wheel running on the face of a larger flat wheel.

    The more to the outside it is positioned the slower the table would turn. Move it with a lever to the opposite side of the flat wheel and the table would reverse.

    Keep in mind this will not have to have a broad range of speeds. The table needs to go from .5 rpm's to maximum 10 rpm's.
    Location: The Black Forest in Germany

    How to become a millionaire: Start out with 10 million and take up machining as a hobby!

  • #2
    Something like a snowblower uses. Maybe even cobble an old snowblower for parts.
    gvasale

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    • #3
      Originally posted by gvasale View Post
      Something like a snowblower uses. Maybe even cobble an old snowblower for parts.
      I googled snowblower transmission and got not much. Do you have a sketch or picture of what you are talking about?
      Location: The Black Forest in Germany

      How to become a millionaire: Start out with 10 million and take up machining as a hobby!

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      • #4
        I can get one from a parts blow up, but it might be faster for you to go and do a web search for Ariens then look for snow blowers model 924050 should bring you right in. Look in the tractor file.
        gvasale

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        • #5
          Originally posted by gvasale View Post
          I can get one from a parts blow up, but it might be faster for you to go and do a web search for Ariens then look for snow blowers model 924050 should bring you right in. Look in the tractor file.
          I went to youtube and found lots of videos on what you mentioned. That is what I was referring to in my original post. Thanks.
          Location: The Black Forest in Germany

          How to become a millionaire: Start out with 10 million and take up machining as a hobby!

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          • #6
            Diagram is cluttered. On the left is the driven pulley from the engine. Nestled on the far right is its counterpart, looks like somewhat circular fins on it. Below to the right is the disk which slid from the center to the rim of the driven flywheel givin variable speed and even reverse rotation. Not much simpler in transmissions, unless you can scrounge up an old Peerless gearbox used on lawn tractors. Those had from 3 to 5 or 6 speeds.
            Last edited by gvasale; 04-12-2015, 09:19 AM. Reason: copied link from their website and it's no good.
            gvasale

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            • #7
              You should be able to find a scooter repair shop around, and get a complete CVT from one. You would have to add a manual control instead of using the variator, but the rest of the parts would be useable as-is.

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              • #8
                what about a typical three speed bicycle hub? built a pulley around it and drive it by a belt, shift on the fly if and when you want?

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                • #9
                  Originally posted by A.K. Boomer View Post
                  what about a typical three speed bicycle hub? built a pulley around it and drive it by a belt, shift on the fly if and when you want?
                  It needs to be infinitely adjustable. I would rather adjust the table than have to adjust my welding style, speed, amps, etc. to fit the speed of the table.
                  Location: The Black Forest in Germany

                  How to become a millionaire: Start out with 10 million and take up machining as a hobby!

                  Comment


                  • #10
                    hmmm - then your idea sounds about as simple as it gets, spring loaded and on a couple of linear slides, you would have to have it running to change speeds but that's how most stuff mechanical is going to be.

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                    • #11
                      One of the riding lawn mowers used the "wheel and disc" drive for years (Maybe Snapper). So I think it would have the right order of magnitude capability. :-)
                      For the 20:1 ratios youre talking about the wheel will have to be pretty good size to have the needed size "inner" track. The mechanism does have the nice
                      reverse capability of the same speed.
                      ...lew...

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                      • #12
                        I once saw some sawmill machinery (what you'd probably call "antique") that used exactly this technique - a wheel riding on a spinning disc mounted at at 90 degrees to it. If I recall, rather than being limited to one radius of travel the wheel may have been able to traverse beyond the axis of the disc, so that the rotation of the wheel was reversed after slowing to zero. That may even have been the main purpose.
                        "A machinist's (WHAP!) best friend (WHAP! WHAP!) is his hammer. (WHAP!)" - Fred Tanner, foreman, Lunenburg Foundry and Engineering machine shop, circa 1979

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                        • #13
                          You can make the variable pulley type system (like a snowmobile) also called a "torque converter"


                          but instead of it being load and RPM activated you have a lever that controls both the growth of one pulley whilst at the same time shrinks the other and visa versa,,, depends on how much range you would need as it does have it's limitations --- but then again snowmobiles can launch off the line and get well into the triple digits so there is some range for sure...

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                          • #14
                            I think you're looking for a "reeves" pulley system. Here are some pics:

                            https://www.google.com/search?q=reev...J&ved=0CD4QsAQ

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                            • #15
                              As Lew states, Snapper does indeed use a wheel and disk system than will give variable speeds. If you could be satisfied with a non variable transmission with gears you might adapt the transmission from an old Honda ATC 90 or 110 or Trail 90 to a speed reducer. They have 4 speeds plus a high and low range and an automatic clutch. I bought one years ago to use on a bandsaw but never got around to the conversion. It's on the list but these days with DC motors and decent drives reasonably priced I may never use it for that.

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