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Re: [AHRC - botlanta] DIY Faro arm

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  • Dale Heatherington
    Can you rent those things? ... -- Dale Heatherington http://www.wa4dsy.net/robot/
    Message 1 of 17 , May 17, 2012
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      Can you rent those things?

      On May 17, 2012, at 5:57 PM, Jebadiah Moulton wrote:

       

      So a rep from Romer came in today,  http://us.romer.com/ .  He demoed he unit and it looks like we can get a real time data stream out of it of the X,Y,Z coordinates.  $50,000.  Bossman will have to decide if he wants to stroke that check.

      On Thu, May 17, 2012 at 8:55 AM, Kirk Charles <kirk@...> wrote:
       

      Jebadiah,
      The Faro is cool because of the single ground point.  The trade off is that you need super accuracy in the encoders and supper stiffness (carbon fiber) in the arms.
      If you don't need the single ground point then you could make a much simpler unit with three arms like those high speed pick and place robots. (I forget what they are called but here is a link http://www.youtube.com/watch?v=gYR7694nUYM&feature=related)  The math is much easier, only 3 encoders are needed, all encoders are at the base, It would not be too hard to add a wrist if needed

      Kirk.





      At 07:58 AM 5/17/2012, you wrote:
       

      How big are the parts?
      -up to 4 feet long.

      What is your budget and do you have a large cnc machine you could add a probe head to?
      -not sure about the budget, just brainstorming now.  The boss wants a Faro or similar type of arm.

      We make a lot of CNC type of scanning equipment but this problem needs human control not machine control.  But we still need the kinematic equations and accuracy of a CNC.  See some of our machines below.
      http://www.youtube.com/watch?v=XSrFfwaiJwY&feature=relmfu
      http://www.youtube.com/watch?v=60c6mpgvEBs&feature=context-chv
      here is someone's video on hand scanning.  This just shows a small weld inspection but we will be doing larger contoured parts.
      http://www.youtube.com/watch?v=uElTf1dmzoU&feature=relmfu

      The encoder string is a good idea but don't think I can get the accuracy.

      On Wed, May 16, 2012 at 11:55 PM, tedrobotbuilder < tedrobotbuilder@...> wrote:
       

      Jebadiah,

      Are you just trying to get the displacement as you move the UT Head? And you have a wheel that has trouble following the contour? How about a string attached to the UT Head, as you move the head it pulls the string which unwinds a spring loaded rotary encoder? That way you wont get any slippage but you wont get the contour either, dunno if that is a problem for you.


      Ted

      --- In botlanta@yahoogroups.com, Jebadiah Moulton <jebadiah.moulton@...> wrote:
      >
      > We are brainstorming about using one of these for ultrasonic inspections,
      > not for 3d modeling. Ex: we have a complex wavy piece of aircraft carbon
      > fiber and we need to inspect it with UT (ultrasound). We usually move the
      > UT probe along the surface and have wheel encoders track where on the part
      > we are moving. The UT instrument plots the UT signal according to the
      > encoder data. If the part is very complex normal encoders will not work.
      > So we are thinking there might be a way to get encoded data out of one of
      > these units and put the UT probe on the end of it. We need at least 0.01"
      > accuracy.
      >
      > On Wed, May 16, 2012 at 9:01 AM, robotguy <robotguy@...> wrote:
      >
      > > **

      > >
      > >
      > > Jebadiah,
      > > It would be possible to make your own faro arm but it would take
      > > some time and alot of coding. A scanner is only as accurate as it is
      > > calibrated ( http://www.youtube.com/watch?v=MqTY1Q9jjjQ ) Don't forget
      > > you need to get a seat of rapidform XOV or polyworks to do validation work.
      > > What are you looking to do?
      > >
      > > Regards,
      > > Mark Fuller
      > >
      > >
      > > ------------------------------
      > > *From:* Jebadiah Moulton <jebadiah.moulton@...>
      > > *To:* botlanta@yahoogroups.com
      > > *Sent:* Wed, May 16, 2012 7:39:39 AM
      > > *Subject:* [AHRC - botlanta] DIY Faro arm

      > >
      > >
      > >
      > > So we are looking at a Faro arm at work. I am assuming it is going to be
      > > several $10,000 from the looks of it. Does anybody have any experience,
      > > advice, or ideas on how I could make my own.
      > >
      > > http://www.faro.com/edge/us
      > > http://www.faro.com/edge/us/applications
      > >
      > > My immediate thought is to have the joints and arm sections machined out
      > > of aluminum or molded out of carbon fiber. Then find extremely accurate
      > > rotary absolute encoders or POTs. Accuracy of near 0.001" would be great.
      > >
      > > What about an IMU unit? Would probably be cheaper to manufacture, but not
      > > sure about accuracy.
      > >
      > > --
      > > Jebadiah Moulton
      > >
      > >
      > >
      > >
      > >
      > >
      >
      >
      >
      > --
      > Jebadiah Moulton
      >




      --
      Jebadiah Moulton




      Charles Photography
                Portrait Artists
      Kirk and Rachel Charles

      1725 Blossom Lane      kirk@...   rachel@...
      Austell, GA 30168        770-739-8214       http://www.charles-photo.com





      --
      Jebadiah Moulton






      --
      Dale Heatherington
      http://www.wa4dsy.net/robot/ 


    • Jebadiah Moulton
      I am sure you can and that might be a possibility for us to determine if it will work. ... -- Jebadiah Moulton
      Message 2 of 17 , May 18, 2012
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        I am sure you can and that might be a possibility for us to determine if it will work.

        On Thu, May 17, 2012 at 8:32 PM, Dale Heatherington <dale@...> wrote:
         

        Can you rent those things?


        On May 17, 2012, at 5:57 PM, Jebadiah Moulton wrote:

         

        So a rep from Romer came in today,  http://us.romer.com/ .  He demoed he unit and it looks like we can get a real time data stream out of it of the X,Y,Z coordinates.  $50,000.  Bossman will have to decide if he wants to stroke that check.

        On Thu, May 17, 2012 at 8:55 AM, Kirk Charles <kirk@...> wrote:
         

        Jebadiah,
        The Faro is cool because of the single ground point.  The trade off is that you need super accuracy in the encoders and supper stiffness (carbon fiber) in the arms.
        If you don't need the single ground point then you could make a much simpler unit with three arms like those high speed pick and place robots. (I forget what they are called but here is a link http://www.youtube.com/watch?v=gYR7694nUYM&feature=related)  The math is much easier, only 3 encoders are needed, all encoders are at the base, It would not be too hard to add a wrist if needed

        Kirk.





        At 07:58 AM 5/17/2012, you wrote:
         

        How big are the parts?
        -up to 4 feet long.

        What is your budget and do you have a large cnc machine you could add a probe head to?
        -not sure about the budget, just brainstorming now.  The boss wants a Faro or similar type of arm.

        We make a lot of CNC type of scanning equipment but this problem needs human control not machine control.  But we still need the kinematic equations and accuracy of a CNC.  See some of our machines below.
        http://www.youtube.com/watch?v=XSrFfwaiJwY&feature=relmfu
        http://www.youtube.com/watch?v=60c6mpgvEBs&feature=context-chv
        here is someone's video on hand scanning.  This just shows a small weld inspection but we will be doing larger contoured parts.
        http://www.youtube.com/watch?v=uElTf1dmzoU&feature=relmfu

        The encoder string is a good idea but don't think I can get the accuracy.

        On Wed, May 16, 2012 at 11:55 PM, tedrobotbuilder < tedrobotbuilder@...> wrote:
         

        Jebadiah,

        Are you just trying to get the displacement as you move the UT Head? And you have a wheel that has trouble following the contour? How about a string attached to the UT Head, as you move the head it pulls the string which unwinds a spring loaded rotary encoder? That way you wont get any slippage but you wont get the contour either, dunno if that is a problem for you.


        Ted

        --- In botlanta@yahoogroups.com, Jebadiah Moulton <jebadiah.moulton@...> wrote:
        >
        > We are brainstorming about using one of these for ultrasonic inspections,
        > not for 3d modeling. Ex: we have a complex wavy piece of aircraft carbon
        > fiber and we need to inspect it with UT (ultrasound). We usually move the
        > UT probe along the surface and have wheel encoders track where on the part
        > we are moving. The UT instrument plots the UT signal according to the
        > encoder data. If the part is very complex normal encoders will not work.
        > So we are thinking there might be a way to get encoded data out of one of
        > these units and put the UT probe on the end of it. We need at least 0.01"
        > accuracy.
        >
        > On Wed, May 16, 2012 at 9:01 AM, robotguy <robotguy@...> wrote:
        >
        > > **

        > >
        > >
        > > Jebadiah,
        > > It would be possible to make your own faro arm but it would take
        > > some time and alot of coding. A scanner is only as accurate as it is
        > > calibrated ( http://www.youtube.com/watch?v=MqTY1Q9jjjQ ) Don't forget
        > > you need to get a seat of rapidform XOV or polyworks to do validation work.
        > > What are you looking to do?
        > >
        > > Regards,
        > > Mark Fuller
        > >
        > >
        > > ------------------------------
        > > *From:* Jebadiah Moulton <jebadiah.moulton@...>
        > > *To:* botlanta@yahoogroups.com
        > > *Sent:* Wed, May 16, 2012 7:39:39 AM
        > > *Subject:* [AHRC - botlanta] DIY Faro arm

        > >
        > >
        > >
        > > So we are looking at a Faro arm at work. I am assuming it is going to be
        > > several $10,000 from the looks of it. Does anybody have any experience,
        > > advice, or ideas on how I could make my own.
        > >
        > > http://www.faro.com/edge/us
        > > http://www.faro.com/edge/us/applications
        > >
        > > My immediate thought is to have the joints and arm sections machined out
        > > of aluminum or molded out of carbon fiber. Then find extremely accurate
        > > rotary absolute encoders or POTs. Accuracy of near 0.001" would be great.
        > >
        > > What about an IMU unit? Would probably be cheaper to manufacture, but not
        > > sure about accuracy.
        > >
        > > --
        > > Jebadiah Moulton
        > >
        > >
        > >
        > >
        > >
        > >
        >
        >
        >
        > --
        > Jebadiah Moulton
        >




        --
        Jebadiah Moulton




        Charles Photography
                  Portrait Artists
        Kirk and Rachel Charles

        1725 Blossom Lane      kirk@...   rachel@...
        Austell, GA 30168        770-739-8214       http://www.charles-photo.com





        --
        Jebadiah Moulton






        --
        Dale Heatherington
        http://www.wa4dsy.net/robot/ 





        --
        Jebadiah Moulton




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