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Re: [rsa] Where's Dave??

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  • Christopher Prosser
    He s at burningman I believe. --chris ... From: Dan Gates To: Sent: Thursday, August 28, 2003 7:10 PM Subject:
    Message 1 of 9 , Aug 28, 2003
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      He's at burningman I believe.
      --chris

      ----- Original Message -----
      From: "Dan Gates" <topazx2@...>
      To: <sfrsa@yahoogroups.com>
      Sent: Thursday, August 28, 2003 7:10 PM
      Subject: [rsa] Where's Dave??


      > Hey, I've been trying to get ahold of David Calkins, did he go on
      > vacation or something??
      > -Dan Gates
      >
      >
      >
      > SF robot meetings are at Noon on the first Saturday of the month at SFSU's
      Science bldg - 1600 Holloway, room SCI 256.
      > http://www.robotics-society.org
      >
      > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
      >
      >
    • Dan Gates
      Ah, That would explain it then, thanks. -Dan ... at SFSU s ... http://docs.yahoo.com/info/terms/
      Message 2 of 9 , Aug 28, 2003
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        Ah,
        That would explain it then, thanks.
        -Dan




        --- In sfrsa@yahoogroups.com, "Christopher Prosser" <cprosser@a...> wrote:
        > He's at burningman I believe.
        > --chris
        >
        > ----- Original Message -----
        > From: "Dan Gates" <topazx2@y...>
        > To: <sfrsa@yahoogroups.com>
        > Sent: Thursday, August 28, 2003 7:10 PM
        > Subject: [rsa] Where's Dave??
        >
        >
        > > Hey, I've been trying to get ahold of David Calkins, did he go on
        > > vacation or something??
        > > -Dan Gates
        > >
        > >
        > >
        > > SF robot meetings are at Noon on the first Saturday of the month
        at SFSU's
        > Science bldg - 1600 Holloway, room SCI 256.
        > > http://www.robotics-society.org
        > >
        > > Your use of Yahoo! Groups is subject to
        http://docs.yahoo.com/info/terms/
        > >
        > >
      • douglas irving repetto
        hi, a friend of mine is working on a bunch of projects that involve rotating cameras. he s been having trouble finding a reliable commutator design. can anyone
        Message 3 of 9 , Aug 30, 2003
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          hi,


          a friend of mine is working on a bunch of projects that involve
          rotating cameras. he's been having trouble finding a reliable
          commutator design. can anyone point me to some online or book-based
          info on commutator design?

          (by "commutator" i mean a device that allows you to feed
          power/signals to a rotating part, as opposed to a device that turns a
          motor's output from AC to DC. is "commutator" the correct word for
          this?)

          thanks,
          douglas


          --
          ................................................http://artbots.org
          .....douglas.....irving.........................http://dorkbot.org
          .................................http://shoko.calarts.edu/musicdsp
          .......... repetto..............http://music.columbia.edu/organism
          ................................http://music.columbia.edu/~douglas
        • David Calkins - RSA
          Most guys build their own...
          Message 4 of 9 , Aug 30, 2003
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            Most guys build their own...

            At 17:34 30-08-03 -0400, you wrote:


            >hi,
            >
            >
            >a friend of mine is working on a bunch of projects that involve
            >rotating cameras. he's been having trouble finding a reliable
            >commutator design. can anyone point me to some online or book-based
            >info on commutator design?
            >
            >(by "commutator" i mean a device that allows you to feed
            >power/signals to a rotating part, as opposed to a device that turns a
            >motor's output from AC to DC. is "commutator" the correct word for
            >this?)
            >
            >thanks,
            >douglas
            >
            >
            >--
            >................................................<http://artbots.org>http://artbots.org
            >.....douglas.....irving.........................<http://dorkbot.org>http://dorkbot.org
            >.................................<http://shoko.calarts.edu/musicdsp>http://shoko.calarts.edu/musicdsp
            >.......... repetto..............<http://music.columbia.edu/organism>http://music.columbia.edu/organism
            >................................<http://music.columbia.edu/~douglas>http://music.columbia.edu/~douglas
            >
            >Yahoo! Groups Sponsor
            >ADVERTISEMENT
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            >536318b.jpg
            >
            >SF robot meetings are at Noon on the first Saturday of the month at SFSU's Science bldg - 1600 Holloway, room SCI 256.
            ><http://www.robotics-society.org>http://www.robotics-society.org
            >
            >Your use of Yahoo! Groups is subject to the <http://docs.yahoo.com/info/terms/>Yahoo! Terms of Service.
          • douglas irving repetto
            ... That s what my friend has been doing (machining his own), but he s having real trouble with wear and noise in his signals. These are art installations that
            Message 5 of 9 , Aug 31, 2003
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              david said:
              >Most guys build their own...

              That's what my friend has been doing (machining his own), but he's
              having real trouble with wear and noise in his signals. These are art
              installations that are on for very long periods of time. He has been
              experimenting with various materials and designs, but can't come up
              with anything that's consistently quiet and durable. Any advice or
              pointers to info?

              thanks,
              douglas





              >At 17:34 30-08-03 -0400, you wrote:
              >
              >
              >>hi,
              >>
              >>
              >>a friend of mine is working on a bunch of projects that involve
              >>rotating cameras. he's been having trouble finding a reliable
              >>commutator design. can anyone point me to some online or book-based
              >>info on commutator design?
              >>
              >>(by "commutator" i mean a device that allows you to feed
              >>power/signals to a rotating part, as opposed to a device that turns a
              >>motor's output from AC to DC. is "commutator" the correct word for
              >>this?)
              >>
              >>thanks,
              > >douglas
              >>
              > >

              --
              ................................................http://artbots.org
              .....douglas.....irving.........................http://dorkbot.org
              .................................http://shoko.calarts.edu/musicdsp
              .......... repetto..............http://music.columbia.edu/organism
              ................................http://music.columbia.edu/~douglas
            • Peter A. Bonucci
              douglas, I don t know your application, but if I needed to get video from one place to another, I would consider an RF or optical link. A photo transmitter
              Message 6 of 9 , Aug 31, 2003
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                douglas,

                I don't know your application, but if I needed to get video from one
                place to another, I would consider an RF or optical link.

                A photo transmitter might shoot down the axle and be received at the
                other end. An RF link could radiate into the room and be received
                anywhere on the other half. It is non-contact, so friction and contact
                noise won't be a problem.

                Price, weight, size, power consumption, and acceptable complexity will
                probably be your major trade-offs. It seems to me that an optical link
                could probably be done for the smallest weight and size, but that may
                not be the trade-off you are looking for.

                Peter A. Bonucci

                douglas irving repetto wrote:
                > david said:
                >
                >>Most guys build their own...
                >
                >
                > That's what my friend has been doing (machining his own), but he's
                > having real trouble with wear and noise in his signals. These are art
                > installations that are on for very long periods of time. He has been
                > experimenting with various materials and designs, but can't come up
                > with anything that's consistently quiet and durable. Any advice or
                > pointers to info?
                >
                > thanks,
                > douglas
                >
                >
                >
                >
                >
                >
                >>At 17:34 30-08-03 -0400, you wrote:
                >>
                >>
                >>
                >>>hi,
                >>>
                >>>
                >>>a friend of mine is working on a bunch of projects that involve
                >>>rotating cameras. he's been having trouble finding a reliable
                >>>commutator design. can anyone point me to some online or book-based
                >>>info on commutator design?
                >>>
                >>>(by "commutator" i mean a device that allows you to feed
                >>>power/signals to a rotating part, as opposed to a device that turns a
                >>>motor's output from AC to DC. is "commutator" the correct word for
                >>>this?)
                >>>
                >>>thanks,
                >>
                >> >douglas
                >>
                >> >
                >
                >
              • Terry Slocum
                Douglas, It depends a lot on what type of signal you are trying to put through it. To control the motors on a crane model I made, I used a piece of copper clad
                Message 7 of 9 , Sep 2, 2003
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                  Douglas,

                  It depends a lot on what type of signal you are trying to put through it. To control the motors on a crane model I made, I used a piece of copper clad circuit board material and etched some rings in it. I used spring loaded brass brushes. It seemed to work fine.

                  If you are trying to pass video, or worse yet modulated video you will have a huge signal loss as soon as the signal leaves the sheilded environment of the cable. Whatever material you use for the "commutator",it will act as an antenna and radiate most of the signal into space. You might try putting a small transmitter in the camera head. Or use something to modulate the video feed onto a low frequence (60hZ) carrier. Some of the low end TV distribution systems work this way. There is also a system for model railroading that lets you put a video camera on the train and transmit video through the wheels to the track.

                  Terry

                  --- In sfrsa@yahoogroups.com, douglas irving repetto <douglas@m...> wrote:
                  >
                  > david said:
                  > >Most guys build their own...
                  >
                  > That's what my friend has been doing (machining his own), but he's
                  > having real trouble with wear and noise in his signals. These are art
                  > installations that are on for very long periods of time. He has been
                  > experimenting with various materials and designs, but can't come up
                  > with anything that's consistently quiet and durable. Any advice or
                  > pointers to info?
                  >
                  > thanks,
                  > douglas
                  >
                  >
                  >
                  >
                  >
                  > >At 17:34 30-08-03 -0400, you wrote:
                  > >
                  > >
                  > >>hi,
                  > >>
                  > >>
                  > >>a friend of mine is working on a bunch of projects that involve
                  > >>rotating cameras. he's been having trouble finding a reliable
                  > >>commutator design. can anyone point me to some online or book-based
                  > >>info on commutator design?
                  > >>
                  > >>(by "commutator" i mean a device that allows you to feed
                  > >>power/signals to a rotating part, as opposed to a device that turns a
                  > >>motor's output from AC to DC. is "commutator" the correct word for
                  > >>this?)
                  > >>
                  > >>thanks,
                  > > >douglas
                  > >>
                  > > >
                  >
                  > --
                  > ................................................http://artbots.org
                  > .....douglas.....irving.........................http://dorkbot.org
                  > .................................http://shoko.calarts.edu/musicdsp
                  > .......... repetto..............http://music.columbia.edu/organism
                  > ................................http://music.columbia.edu/~douglas
                • douglas irving repetto
                  a while ago i asked for some advice on commutator designs for a friend of mine. he s just found what looks like a really good (albeit pre-made) solution:
                  Message 8 of 9 , Sep 9, 2003
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                    a while ago i asked for some advice on commutator designs for a
                    friend of mine. he's just found what looks like a really good (albeit
                    pre-made) solution:

                    http://www.mercotac.com/index.html


                    i'm not sure what the price on these is.



                    douglas





                    --
                    ................................................http://artbots.org
                    .....douglas.....irving.........................http://dorkbot.org
                    .................................http://shoko.calarts.edu/musicdsp
                    .......... repetto..............http://music.columbia.edu/organism
                    ................................http://music.columbia.edu/~douglas
                  • Al Margolis(TX)
                    McMaster-Carr has some. Search for rotating electrical connectors at http://www.mcmaster.com. -- Al Margolis, founder www.hobbyengineering.com The WEB s
                    Message 9 of 9 , Sep 9, 2003
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                      McMaster-Carr has some. Search for "rotating electrical connectors" at
                      http://www.mcmaster.com

                      -- Al Margolis, founder
                      www.hobbyengineering.com
                      The WEB's newest source for robotics supplies and information

                      -----Original Message-----
                      From: douglas irving repetto [mailto:douglas@...]
                      Sent: Tuesday, September 09, 2003 1:52 PM
                      To: sfrsa@yahoogroups.com
                      Subject: Re: [rsa] commutator questions



                      a while ago i asked for some advice on commutator designs for a
                      friend of mine. he's just found what looks like a really good (albeit
                      pre-made) solution:

                      http://www.mercotac.com/index.html


                      i'm not sure what the price on these is.



                      douglas





                      --
                      ................................................http://artbots.org
                      .....douglas.....irving.........................http://dorkbot.org
                      .................................http://shoko.calarts.edu/musicdsp
                      .......... repetto..............http://music.columbia.edu/organism
                      ................................http://music.columbia.edu/~douglas


                      SF robot meetings are at Noon on the first Saturday of the month at SFSU's
                      Science bldg - 1600 Holloway, room SCI 256.
                      http://www.robotics-society.org

                      Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
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