Taz 6 - can't get linux to recognize printer when I plug in USB and hit "connect"

I have a Lulzbot Taz 6 that I don’t use very often. I got it back in I believe 2018. I previously had the single print head, and I wanted to do the dual-head update so I bought the v3.1 dual head the other day.

Previously (back in 2018 when I got this) I remember I had a problem where I could not get the computer (I use Linux Mint) to recognize the TAZ6 when I plugged in the USB and tried to connect with Cura. I ended up just doing my slicing in CURA, and then copying the gcode file to a little SD CARD and then putting it directly into the printer. This worked for years.

Now yesterday I had to install the dual head and I had to update the firmware. I downloaded the newest version of CURA from the site first. Before trying to update the firmware I went into the LCD screen and took pictures of the E-steps number with my phone as they ask you to write it down before updating the firmware. Once again, I could not get CURA to recognize the printer. I would click connect and it could not find it.

I ended up using a different laptop with windows 10 to install cura and I was able to connect with it just fine. I updated the firmware that way.

I seem to remember somewhere seeing something about a fix for this, but I should have taken a photo with my phone on what to do. I can’t remember what it was for the life of me. I tried searching again and can’t find it.

Update- I got this to connect on Linux today by going into the terminal and launching the appimage as sudo. However I tried to run the command:
sudo usermod -aG dialout [your username]
which did not seem to make a difference.

Not sure why I can’t make it connect by adding just my regular name to dialout group.

It sounds like you need the help of a Linux group more than Lulzbot group. I think most the experts on here run Windows or iOS.

I have my TAZ 6 connected to a Raspberry Pi 3B running OctoPi / OctoPrint. OctoPi is Raspbian Lite with OctoPrint pre-installed. Raspbian (or Raspberry Pi OS) is Debian which is based on Linux. You might get some help from the folks in the OctoPrint forum or their Discord.

Since you have both the Single Extruder and the Dual Extruder V3.1, you need to flash the firmware each time you change the extruder. One tip I’ve learned is to flash the firmware for the single extruder while the dual extruder is still installed. If you switch the extruder before flashing the firmware, you get into an error state and can’t flash the firmware (because the second extruder thermistor is missing).

You can “fake it” with a 100K ohm resistor. See https://forum.lulzbot.com/t/dual-extruder-dummy-plug-for-second-connector/5946 for the details.