Video: How Not To Treat Your 3D Printer Electronics

  • administrators

    I recorded a short video to showcase our attempts to make revision 1.02 of the Duet WiFi even more robust than earlier revisions. I'm a novice at making videos, so please excuse the poor production quality.

    Feel free to link to this video on your other favourite forums.

    Please note, this video is about things you should NOT do. So don't do them!

  • Pretty neat, I wish I had gotten versions of the Duet Wifi boards of similar versions! Each time I did, even for a nanosecond, any of the depicted "what NOT to do" acts –-> board go boom. Cheers for making a headway on making that harder to do to your awesome boards!

    Thanks for everything,


  • administrators

    Thank you! Actually, even though the new board has additional protection features, I did the stepper motor disconnect test on older versions of the Duet WiFi and the board still survived, although I didn't test quite as many disconnects. Now that I have some 2.8A motors, I'll test again at 2.4A current.

    The short to VSSA test is something that would have blown the VSSA fuse on earlier Duets. When I designed the original Duet WiFi I expected the VSSA fuse to save a few boards in every thousand from irreparable damage. But it's become clear that shorts between thermistor leads and 12V or 24V are much more common than I expected. That is why I redesigned the protection in revision 1.02. There is an extra feature to handle such a short that I didn't reveal in the video, but I'm not going to spoil the surprise!

  • David,

    A very quick question. Would using a PT100 or thermocouple be any less likely to damage a Duet board in the event of a failure or short, than a thermistor? i.e. would putting 24v down a PT100 or thermistor wire still wreak the same havoc as a putting 24v down a thermistor wire or would it simply wreck the daughter board?

  • As cool as this is, from a hardware perspective, I would prefer if the firmware had gone into failure mode when you (virtually) disconnected the thermistors - are there no watchdog safety feature in the firmware that monitors for disconnected thermistors, in case the wires break?

  • administrators

    Ian, the chips on the PT100 boards are rated to more than 40V input so a short to 24V should be no problem. The chips on the thermocouple board have no such protection.

    @Kulitorum, of course there are safety features to detect malfunctioning thermistors, but they only kick in when you are powering the corresponding heater. You wouldn't want the board continually shutting down while you were trying to commission it and hadn't connected and configured all the thermistors.

  • Nice work big thumds up
    Wish i had one of the new boards and not the early on as i have blown my vssa fuse and am running a glass fuse mine happenex when installing a volcano heater wiretouching hot end and a thirmister with very thin ptf tube that i over tighten and must of shredden the tube

    P.s love the video i personal would like to see some more videos cover setup of the more common questions you see

  • administrators

    Perhaps I should do a video on how to fit a resetable fuse to the older boards?

  • please do if your taking requests id also like to see a video on ir probe install and set up as your right ups are very technical and a show and tell would help us mortals keep up with you are have a better understanding of it

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