Use whole build plate with Dual Extruder

Using the dual extruder on my TAZ6 is causing the available portion of the build plate to be cut down to 280mm x 180mm because of the extruder offset of -50mm in the Y axis for the second extruder. This is also the case in Cura2. The only way around this that I’ve found is to expand the Y axis on the machine to 380mm, and to then adjust the machine offsets in the other direction by 50mm for both heads. It works fine until the machine attempts to make a move back to X0, Y0, which it does periodically. At that point it hits the Y end stop and throws off all future moves.

As far as I can tell this is really just a software issue. I can edit resulting gocde files by hand to address the issues, but I’d much rather not have to post-process my files (especially by hand), and I don’t know

Anyone running into this issue, or resolving it in a different way that doesn’t cause this problem?

After a few more weeks of fooling around, I figured out how to make this work - detailed below:

  • Make a new TAZ6 DualExtruder v2 using stock options.

  • Go to Manage Printers in the Preferences panel and click on the Machine Settings button.

  • Go to the Extruder 2 tab.

  • Change the Nozzle offset Y to “0.0mm”

  • Change the Extruder State Gcode to:
G1 Y140          ;Move Y to middle
G92 Y90          ;Reset Y values as shifted down

  • Change the Extruder End Gcode to:
G1 Y90           ;Move Y to middle
G92 Y140         ;Reset Y values as shifted up

That’s all you need. I’ve since run parts right out to the Y extremes with both heads and had no problems. The only parts I’ve run out that far have relatively short tests specifically for checking to see if this is possible. When I actually need to run something off that’s large enough to require both heads to hit the Y-axis extremes of my bed, I’ll post an update, especially if I run into any problems.

Great info! Thanks for posting it!

How did you figure out what to change to get the results you needed?


There’s a bunch of different ways to accomplish this with commands either in the machine start code and machine settings or in the nozzle start/end code. This one ended up with the fewest potential problems (like possibly printing off the bed, or being unable to accommodate a re-home mid-job) even though it slows the overall print down slightly by making an extra rapid move in any layer that uses both heads. The comments explain the moves I direct the printer to make. If you haven’t read through the G/M code library published on the reprap wiki, I highly recommend it, and that’ll explain further what I’m asking the printer to do.