Quote Originally Posted by jfkansas View Post
It has to do with how big the machine is. If they separate the extruders more the x travel would need to be lengthened so both extruders can hit all spots on the build plate. Also as you increase the x travel bars the more they can sag in the middle due to the extruder weight. That brings up some more issues, a wider space between the extruders means the extruder assembly will weigh more and that makes more weight to move back and forth, more weight to stop/change directions, etc. You would probably have to slow down the travel or the belts will skip. It is all a trade off. For now until I need to do dual extrusion I have removed my left extruder stepper motor. I haven't increased travel speed yet but I intend to eventually to see if I can gain some print speed due to the lighter extruder weight.
Yep, I actually would prefer the extruders to be closer together (wha?) yeah, when they are set up right and don't drag, ideally they could be even closer together. This would allow a bigger build area, and levelling the build plate would also be easier.

The problem I have that is a constant on my machine is the slightly sagging heatbed (should have a new one soon) when you level the heatbed, you will find the extruder closest to the edge is always a tighter tolerance to the one closer to the center of the plate. I have adjusted the height of my nozzles to compensate for this, but ideally I wouldn't have liked to do that. If they were set at even 20mm apart, this would facilitate in getting the hot bed even more level because both nozzles are closer to the edge giving you a more precise area to level rather than that rough inch you need to account for due to one nozzle not being on the edge of the platform.