Online printing/rasperry/octoprint

  • Hi

    I would like to control my CR-6 SE using a raspberry pi running octoprint.
    Internet is full of stories about burning rasperry pi when connecting it to the CR-6SE using a USB cable.

    Can any representative from Creality clarify the current status on this issue???

    ( reason I am asking is that I just recived my CR6. The manual talking about online printing by connecting a PC to the CR-6 using a USB cable. Is this possible? I dont see any difference on a PC or a Raspberry PI , from a USB point of view. )

  • @lg-lindstrom Supposedly. A bunch of users have reported that they've had no issues with USB on their boards, having used USB before hearing about the fried boards and USB ports, and Creality has made a comment that people assume relates to this issue, saying it affects a small number of boards. But it's hard to tell, for sure, since there are a bunch of serious hardware and software issues with this printer, and Creality has officially addressed two issues, but neither makes specific mention to the actual issue, so what they're referring to is guesswork based on the timing of when the statements were published.

    And as you can see from this thread, Creality hasn't exactly exelled in responding to user requests and feedback.

  • @shinmai said in Online printing/rasperry/octoprint:

    I generally believe Creality's estimate of under 1% of stock being defective

    So,, this is a production issue, not a design fault ??

  • @admin what?
    This is about the bug with CR-6 SE's micro-USB connector potentially frying the motherboard AND the computer it's connected to. Has nothing to do with Z-height, auto bed leveling OR the Ender 3.

  • Dear @lg-lindstrom

    1. Has the machine been retrofitted with BL TOUCH; if so, you can try to increase the z-axis compensation; not to change the memory card when printing.
      2.If BL TOUCH has not been installed, please check if the printhead kit is loose.
    2. Reflash firmware
      Ender-3 V2-Marlin-2.0.1 - V1.0.2(1).bin

  • @lg-lindstrom said in Online printing/rasperry/octoprint:

    Can any representative from Creality clarify the current status on this issue???

    I wouldn't hold my breath waiting for this. If they haven't weighed in on it by now, I doubt they will. The issue ISN'T incredibly wide-spread, I generally believe Creality's estimate of under 1% of stock being defective, but given what's at stake, I wouldn't take the risk.

    That being said, the problem seems to be that the control board applies (a rather high) voltage on the VCC line of the USB connector (something that a client device wouldn't do, according to USB specifications, the host side provides 5V on the VCC line for the client to use). This added to the normal voltage the host side applies on the line, causes a MASSIVE (relatively, by USB standards) voltage differential between the VCC and GND lines, in the magnitude of tens of volts, way more than twice the expected value, causing damage to most devices.

    Now this is a pretty easy issue to fix. Some people just tape the VCC pin on their USB A connector (I personally find this way too error prone and would opt for any of the other options), but I'd recommend either splicing open a USB cable, completely disconnecting the VCC line by cutting out a good length, a few cm at least, of the connector (usually marked with red insulation, but best to double check) and applying heat-shrink tubing or electrical tape over the area, or alternatively if you don't want to ruin a USB cable, buying a device that does the same. A popular option is Brian Lough's Power Blough-R, which is a very clean and reliable way to disconnect the VCC line.

    I've only heard of one case of damage from attaching USB with a cable with VCC disconnected, and that user had opted for the taped connector solution, which I suspect could have failed either from the tape shifting from the friciton of inserting the USB cable, or not being enough insulation for the 20-ish volts on the line. I've not heard of a single user whoös USB port has fried when using a cut cable or an isolating adapter.

    It's definitely possible to use the CR-6 with OctoPrint or using a PC as a host, but it's best to take care before doing so. Creality have been... decent about replacing fried control boards, but don't cover any damages to computers or Raspberry Pis, which for a lot of users would be the much bigger worry. Also Creality support is GLACIALLY slow. I've been waiting 2½ half weeks on a reply to my e-mail, with no reply from them, and me following up twice afterwards already.
    Peole who have received replacements have reported it taking 2-3 months from initial contact to happen.

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