diff -r ea4c43494a19 -r f7e9bd735ce1 printrun-src/printrun/pronterface.py
--- a/printrun-src/printrun/pronterface.py	Thu May 30 19:02:52 2019 +0200
+++ b/printrun-src/printrun/pronterface.py	Tue Jan 19 20:25:47 2021 +0100
@@ -316,6 +316,7 @@
     def _lc_add_settings(self, size):
         # first add the lasercutter options
         self.settings._add(StaticTextSetting("separator_lc_general", "General laser settings", "", group = "Laser"))
+        self.settings._add(BooleanSetting("lc_melzi_hack", False, "Use Melzi M571 Hack instead M3/M5", "no description :)", "Laser"), self.update_lc_settings)
         self.settings._add(SpinSetting("lc_travel_speed", 120, 1, 300, "Travel speed in mm/s", "", "Laser"), self.update_lc_settings)
         self.settings._add(SpinSetting("lc_engrave_speed", 10, 1, 300, "Engrave speed in mm/s", "", "Laser"), self.update_lc_settings)
         self.settings._add(SpinSetting("lc_z_focus", 16, -80, 80, "Laser Z focus position", "", "Laser"), self.update_lc_settings)
@@ -325,7 +326,7 @@
 
         self.settings._add(StaticTextSetting("separator_lc_bitmap", "PNG Bitmap processing", "", group = "Laser"))
         self.settings._add(FloatSpinSetting("lc_bitmap_speed_factor", 1.0, 0.1, 2.0, "Engrave speed factor", "", "Laser"), self.update_lc_settings)
-        self.settings._add(SpinSetting("lc_dpi", 300, 25, 300, "Image DPI", "Image resolution for scaling", "Laser"), self.update_lc_settings)
+        self.settings._add(SpinSetting("lc_dpi", 300, 25, 600, "Image DPI", "Image resolution for scaling", "Laser"), self.update_lc_settings)
         self.settings._add(SpinSetting("lc_grey_threshold", 0, 0, 255, "Grey threshold value for RGB", "", "Laser"), self.update_lc_settings)
         self.settings._add(BooleanSetting("lc_invert_cut", True, "PNG: Invert grey threshold", "Invert laser on/off logic", "Laser"), self.update_lc_settings)
         self.settings._add(BooleanSetting("lc_change_dir", True, "PNG: Change direction", "Engrave in both directions on Y Axis", "Laser"), self.update_lc_settings)
@@ -336,8 +337,8 @@
         self.settings._add(StaticTextSetting("separator_lc_svg", "SVG processing", "", group = "Laser"))
         self.settings._add(FloatSpinSetting("lc_svg_speed_factor", 1.0, 0.1, 2.0, "Engrave speed factor", "", "Laser"), self.update_lc_settings)
         self.settings._add(FloatSpinSetting("lc_svg_smoothness", 0.2, 0.1, 10.0, "Smoothness", "Smoothness of curves (smaller value = smoother curve)", "Laser"), self.update_lc_settings)
-        self.settings._add(SpinSetting("lc_svg_width", 50, 1, 250, "Width (mm)", "Image width", "Laser"), self.update_lc_settings)
-        self.settings._add(SpinSetting("lc_svg_height", 50, 1, 250, "Height (mm)", "Image height", "Laser"), self.update_lc_settings)
+        self.settings._add(SpinSetting("lc_svg_width", 50, 1, 9999, "Width (mm)", "Image width", "Laser"), self.update_lc_settings)
+        self.settings._add(SpinSetting("lc_svg_height", 50, 1, 9999, "Height (mm)", "Image height", "Laser"), self.update_lc_settings)
         self.settings._add(ComboSetting("lc_svg_scalemode", "original", ["original", "scale", "stretch"], "Scaling mode", "scale/stretch to above dimensions", "Laser"), self.update_lc_settings)
         self.settings._add(BooleanSetting("lc_svg_offset", True, "Calculate offset to X=0, Y=0", "If enabled, move image to origin position", "Laser"), self.update_lc_settings)