Changing settings at Z-height

I've been watching various youtube videos, both relating to printing specific parts and also new filament calibration.

The demonstrations I've seen have been using both Simplify3D and Cura. In both instances it seems the operator is able to specify various Z-bands and set different temperatures or change other settings. So for filament calibration one person showed how he would print a 1 perimeter hollow tower and adjust the temperature by 5 degrees every 5mm. This means in one print, he can evaluate the bonding properties of a particular reel of filament at a wide range of temperatures. After this he did the same thing except with his temperature constant he adjusted the extrusion multiplier.

In another example, this time in Simplify3D, the model in question required 2 perimeters for the first few mm of printing, after which this should change to 1 perimeter. It was demonstrated that one batch of settings could be applied from 0-5mm and another from 5mm onward.

I'm not sure of the correct term for describing this functionality so have been searching to see whether I can do this in Slic3r but so far without luck. I imagine that I could generate me G-Code and then manually edit it at specific layers to for example change the hotend temperature, however, this isn't particularly user friendly.

Does anyone know whether this is possible? I'm an occasional/light user and having gotten to a point where I have reasonably good and consistent results using Slic3r I don't really want ot have to start again with a new slicer.

Edited 1 time(s). Last edit at 12/14/2016 05:47AM by JBFUK.

You can't do that sort of stuff directly in slic3r, but gcode is easy to edit manually. If you want to change the temperature every 5 mm of Z height, search the text for z=5.0, then insert a line that sets the temperature to the value you want. Then do a search for z=10.0, etc.

It's amazing what a difference of 5-10C makes on the strength of the bond between layers. When you print that single walled tower at varying temperatures, you'll see the print surface quality change with temperature and if you try to pull the layers apart, at temps that are too low they will separate pretty easily and once you get to the right temperature, you'll have a very hard time pulling them apart. When you get above that temperature by much, the surface quality will start to change, usually in undesirable ways.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Thanks for the reply. Any idea whether it would be possible to do the same for the extrusion multiplier?

So it looks like this is possible via modifier meshes. I'm reading up on it now:

[slic3r.org]

M221 should allow you to set that. See: [reprap.org]

Extrusion multiplier usually need only be set once for a given spool of filament, unless the diameter varies significantly throughout the spool, in which case you should probably look into getting better quality filament. A few 10s of um in filament diameter will have an impact on print quality. The usual way to set extrusion multiplier is to slice a 1 or 2 walled object using the nominal filament diameter and fully specifying the line widths, print the object and measure the wall thickness. Use the measured thickness to calculate the extrusion multiplier then mark that multiplier on the spool for future reference.

Alternatively, you can calculate an average diameter from 20-30 measurements of the actual diameter (mark it on the spool!) and use that diameter when you slice (or when you print if you use volumetric extrusion). This assumes you calibrated the extruder correctly by entering the measured filament diameter when you did the extruder calibration. I prefer this method because I don't have to make test prints with every spool of filament (but I do have to measure and calculate). Volumetric extrusion is nice because you can use the same gcode file with any spool of same-material filament because you enter the actual diameter at print time. I get very consistent print quality this way.

Either way works.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Thanks it does look like M221 will do it. I will test for temperature first (manual Gcode edits) and then if successful with the multiplier. This is mainly for fine tuning with a new spool of filament. I find particularly that different colours of PETG (which I use exclusively now) can require quite different temp and multiplier settings. If I get myself setup with a couple of G-code files to help me calibrate temperature and multiplier for a new spool then I should be able to produce good results without too much messing around.