Quote Originally Posted by curious aardvark View Post
like the bnc3d sigma.
That's very interesting. I'm guessing it uses two independent limit switches for homing on the gantry axis, to home each extruder, one to each side? Plus it has a proprietary calibration sequence built into the machine to get it to work right. I wonder if you could do this on a DIY machine?

Looks like they used very nice linear components for the X and Y but for some reason used unsupported 10mm linear rods for the Z axis.

So is the common problem with dual extruders one extruder leaking on the print or misalignment with one nozzle higher or lower than the other?