Different offsets for PLA vs ABS?

[tsteever]

I am trying out PLA but I am having a terrible time. I had everything set well for ABS (nice solid first layer). When I use the same settings (different heat setting) for PLA the first layer is horrible. It requires a bit different z offset. What gives?

[adamfilip]

probably need to adjust your extrusion multipler
each filament will have its own.

[AbuMaia]

As PLA prints cooler than ABS, your hotend is also cooler, and will not have expanded as much as it would for ABS. Same with the bed temperature. The bed at a lower temp for PLA will be farther away from the nozzle than with ABS. You should need a slightly larger offset with PLA than with ABS, since the nozzle and bed will be further apart at the lower temperature.

[SgtToe]

So noob question, does octoprint or the ramps/rumba boards have a way to store profiles? So that you can tweak the settings for ABS and save them and then set one for PLA and be able to switch? Or does one just keep a journal so you can manually reenter the settings when swtiching back and forth between filament types?

[jasay]

So noob question, does octoprint or the ramps/rumba boards have a way to store profiles? So that you can tweak the settings for ABS and save them and then set one for PLA and be able to switch? Or does one just keep a journal so you can manually reenter the settings when swtiching back and forth between filament types?

I deal with this in slic3r. There is a z offset on the last tab ("Printer settings") and I just have different profiles for different materials as I slice the stl. I wouldn't want to use the same gcode file in octoprint/pronterface/cura/etc anyway since temperatures, filament diameters, etc can be different.

Note that this is a different z offset from the ABL offset. This one changes the z heights in the g-codes and so will be basically equal to amount that the nozzle lengthens with temperature.