Gcode Speed Syntax - PrusaSlicer https://forum.prusa3d.com/forum/prusaslicer/gcode-speed-syntax/ Prusa3D Forum Discussion Board en-US Sat, 25 Apr 2026 03:23:30 +0000 wpForo 60 Gcode Speed Syntax https://forum.prusa3d.com/forum/prusaslicer/gcode-speed-syntax/#post-155328 Fri, 26 Jul 2019 18:45:30 +0000 Hi, firstly I need to mention that I am stuck using an older version of Marlin and that I am aware some of these issues may be fixed in newer versions.

My main issue is regarding the placement of the F__ speed parameter on its own line with G1: "G1 F500" before the actual movement "G1 X_ Y_" line. My firmware won't recognize an "F" without a specified axis in the same line and ignores it. For example:

G1 E1 F2000
G1 F500
G1 X97.362 Y74.737 E1.65204
G1 X101.000 Y82.093 E1.65195
G1 X97.482 Y82.093 E0.79009
G1 E-1.000 F2000
G1 X83.327 Y82.093 F1500
G1 E1.000 F2000
G1 F500
G1 X78.507 Y82.093 E1.08246

I want to print at F500 but it never does because the printing moves only adopt the previous valid line with F2000. I have tried slicing with the different firmware flavors but they all seem to do this. Can there be an option to place the F parameter in the first G1 line along with the axes instead of by itself?

My other request is that there be a separate option for specifying Z movement speed. Right now it seems coupled with the X/Y "Speed for non-print moves", and the only way to make it lower is to set the machine speed limits. Thanks.

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