Duet3D Logo

    Duet3D

    • Register
    • Login
    • Search
    • Categories
    • Tags
    • Documentation
    • Order

    Are toolboards hot-swappable?

    Duet Hardware and wiring
    2
    3
    116
    Loading More Posts
    • Oldest to Newest
    • Newest to Oldest
    • Most Votes
    Reply
    • Reply as topic
    Log in to reply
    This topic has been deleted. Only users with topic management privileges can see it.
    • p8blr
      p8blr last edited by

      I'm curious that if one were to build a printer using a robotic tool changer that would pass through the electrical connections (Example: ATI pogo-pins ) would the Duet 3 be able to handle toolboards being connected and disconnected mid print?

      A potential downside I see is not being able to keep the unused tools heated when not in use, but if this is possible maybe some of you have ideas on how to mitigate this issue.

      Thanks.

      1 Reply Last reply Reply Quote 0
      • dc42
        dc42 administrators last edited by

        I can see two issues with hot-swapping tool boards:

        1. Because of the capacitors on the VIN rail, there would be a large surge current when the pogo pins mate. I tried hot-plugging one and there was a fat spark. You would need to mitigate this, for example by connecting the tool board initially with a resistor in series with VIN, then bypassing the resistor after a short delay.

        2. You would need to wire it so that the CAN bus isn't broken when the board is disconnected. You could wire the CAN bus to the pogo pins and onward from them, and then use just 2 wires and 2 pogo pins to connect the CAN bus to the tool board.

        BTW there is a patent (bought by Stratasys) on tool changing 3D printers using pogo pins.

        Duet WiFi hardware designer and firmware engineer
        Please do not ask me for Duet support via PM or email, use the forum
        http://www.escher3d.com, https://miscsolutions.wordpress.com

        p8blr 1 Reply Last reply Reply Quote 0
        • p8blr
          p8blr @dc42 last edited by p8blr

          @dc42 Oh yes, I’ve battled sparks building quadcopters, but the ESCs on them have capacitors on the input wires to prevent that. You can even get anti-spark XT90 connectors. Or perhaps a solid state relay could be used to connect/disconnect power during the tool change cycle.

          Looking at patent US8926484B1 seems to be problematic though. The way it’s worded, if the tool changer connects any sort of electrical connection then it conflicts... I bet that’s why E3D only mechanically couples their tool changer.

          1 Reply Last reply Reply Quote 0
          • First post
            Last post
          Unless otherwise noted, all forum content is licensed under CC-BY-SA