New problems

Been an interesting few days. I mentioned in another post that my printer has started doing a weirdness: every 2nd print, or nearly every 2nd one, instead of actually printing, it just sits at the home position and spits out filament as fast as it can, so fast the extruder chatters. If I power cycle the printer, or cause the controller to reset by unplugging the USB cable then plugging it back, the next print will virtually always work. Obviously though, it does mean something is off, but what?

Today I got to tracking it down. There were several candidates: [LIST=1]

  • the printer's controller (some of you may recall me mentioning how I accidentally let some of the magic smoke out a couple of months ago);
  • the Surface Pro I've been using to control the printing;
  • the installation of Cura (maybe something got corrupted?). [/LIST] To address item 2, I did a fresh install of Cura on another computer and tried test prints. Again, every couple of prints, or so, it would just spit out filament. Resetting would fix it, for a while.

    However, with the new computer, a new problem occurred: the printing would pause, for no known reason, for 3 or 4 seconds, then pick up again.

    In any case, it was clear that the Surface Pro is not the source of the problems. And, since it was a fresh install of Cura, with fresh profiles from CHEP, it wasn’t Cura either.

    Pehaps it printing over USB that’s the problem. Nope: reverting back to micro SD card has the same problem.

    So, I think that pretty much nails it: it’s the control board.

    I’m also wondering if this issue is responsible for some of the ugly prints I’ve been getting yesterday & today:

    [ATTACH=JSON]{“data-align”:“none”,“data-size”:“medium”,“data-tempid”:“temp_487_1597543550211_642”}[/ATTACH][IMG2=JSON]{“data-align”:“none”,“data-size”:“full”,“src”:“;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw==”}[/IMG2]​ [ATTACH=JSON]{“data-align”:“none”,“data-size”:“medium”,“data-tempid”:“temp_489_1597543564129_934”}[/ATTACH][IMG2=JSON]{“data-align”:“none”,“data-size”:“full”,“src”:“;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw==”}[/IMG2]​ [ATTACH=JSON]{“data-align”:“none”,“data-size”:“medium”,“data-tempid”:“temp_488_1597543571621_161”}[/ATTACH][IMG2=JSON]{“data-align”:“none”,“data-size”:“full”,“src”:“;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw==”}[/IMG2]​

    The first 2 photos are the edge that was closest to the front of the printer. The 3rd photo is of the item opened up (it’s a wired bracket for network cabling). Notice, in the 3rd photo, all the zits/bumps/blobs. I tried playing with the retraction. Turning it completely off was the best (the 3rd photo).

    Bottom line: I think I’m going to have to get a new control board. Obviously I want a 32-bit board, but which one. I know DrVAX likes the TH3D EZ Lite, and it isa robust board; the only 1 I know of that doesn’t have heat sinks on the TMC2208 drivers, because it doesn’t need them, the board is desgned that well.

    OTOH, as far as I can determine, it doesn’t support multiple extruders, something I would like to keep as an option for the future.

    Do I go for something like a Duet, which costs more, but does support multiple extruders?

    I see on Amazon that BTT 1.3 & 1.4 boards do support multiple extruders, but are they good?

    I’m looking for suggestions…

  • the pictures are not visible.

    The BTT boards have changeable driver chips (chopsticks), which make it easy to be replaced, when something goes wrong. It may be a little more expensive, but as the drivers, beside the mosfets, are the only component on the board, which can really be forced to its limits, I would always go that way.

    In the end you can always swap/replace single drivers to find out where a problem is located.

    I also would recommend to go for the 2209 chips, which are a combination of everything before with the complete range of features. CoolStep and StallGuard, features you maybe later on will interested in, are not available with the 2208. You even can mix them if you want it cheap. You can use TMC2209 for X and Y and crappy A4489 for Z and E1/E2.

    The boards itself are great. Build quality and accessibility. Firmware update is done by the boards itself. Just write the firmware.bin onto the SD card and power the board up. Done. No need for serial adapters or external tools. All potential features are available via jumper, were on other solutions you need wire harnesses or extra stuff.

    And the best is you even get a small yellow rubber duck to play in the bath tub. :smiley:

    I got the “your post requires administrative approval” message on this post, so I copied the contents and made a new post with them. I find the criteria for requiring admin approval are set too sensitive.

    Big Tree Tech produce the SKR series succesfully. SKR 1.4 TURBO is the best they ever create. Use this one combining with TMC 2209 in UART mode and you’ll have a robust BOB. It supports multiple extruders as well. Marlin or REPRAP fw.

    I’m considering it. Before I commit I have to check out this whole “sensorless homing” topic.