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Intermittent stepper motor and servo response

edited January 2013 in Egg-Bot
I've assembled by Egg-Bot and have been able to use Inkscape with the Egg-Bot extensions to manually control my unit as well as print. But sometimes the Egg-bot will stop responding. It doesn't happen in the middle of a run. I'll use manual control to rotate both steppers and lift and drop the pen to ensure it is all working. But when I click on Apply on the Plot tab, sometimes nothing happens. The green LEDs on the EBB are solid green or flashing and the red LEDs are flashing like they are sending commands to the steppers and servo, but nothing is moving. I'll cancel the print and select Enable Motors on the Manual tab and click apply then try manual control again but now nothing happens. I've cycled the power, disconnected the USB cable and reconnected, checked all wires leading to the steppers and the servo. The last time this happened I shut everything down including my computer and restarted and then it all worked. Anyone had this problem before? I'm using Windows 7 and the latest version of InkScape, USB driver, and Eggbot extension (I just downloaded it today).

It's driving me nuts since I can't predict when it will happen. Most of the time it works fine. But when it glitches, I haven't figured out why or how to recover reliably.


  • If Inkscape is not giving you any errors, it sounds like a connection problem, as though the 9 V power supply is not connected.  I'd suggest *unplugging* the 9 V power supply, plugging it back in, and trying again.  Also, make sure that the EBB lights up when only the 9 V power supply is plugged in, that is, without the USB cable plugged in.
  • I've been troubleshooting and haven't been able to narrow it down since it is an intermittent problem.  Can someone tell me if the following assumptions are correct:

    Following the circuit diagram, it look like:

    Green power LED lights when EBB is connected to the computer (USB) and disconnected from the power adapter.

    Green power LED lights when EBB is connected to the power adapter and disconnected from the computer.


    When Inkscape is sending commands to the EBB:

    Red LED lights when commands are being sent to the individual steppers.  The red LEDs will still blink on and off during this process even if the power adapter is not connected.

    The steppers hum when they are active but not moving.

    Like you, I also suspect something is wrong with the power connection to the board.  The plug on the power supply, the socket, or the connection between the socket and the board. 


  • Yes, the power LED and direction LEDs will be lit if the board is receiving power from either the 9 V power supply or (if that is not connected) USB.

    If the steppers are humming or energized (resisting motion), then the 9V power is indeed reaching the board.  That's by far the best indicator.

    Are you receiving any error messages within Inkscape?
  • edited January 2013
    Ok, getting closer.  If I plug in the power supply, the green LEDs do NOT light up.  If I plug in the USB, the green LEDs do light.  

    If I remove the USB plug, then insert and remove the power supply plug a few times, then the green LEDs light up. 

    So it seems like something is wrong with the adapter, the plug, the socket, or something on the board.  I need to pull the board and look at it under magnification. 

    Oh no errors from Inkscape.  It thinks everything is a-ok.
  • So yes, something is definitely wrong with either the plug, socket or board. :(

    Please contact our store directly to see about getting replacement parts:
  • I can't see any problems. I'll send them an e-mail. Thanks for your help.
  • So how long does it typically take for them to respond? I sent them a message late on the 24th with copy to me so I know it was sent. Should I just try and call them?
  • Nevermind.  I got an email yesterday and am sending the board and the power supply for them to look at.
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