Mach4 Toolpath Preview and UI tips

Hope everyone is enjoying their Sunday! I spent a little time at the machine this weekend, debugging my upcoming parametric Spoilboard Wizard. I’ve also had some great conversations recently with CNC newbies. I thought I might share some tips we had come up in those conversations. This is all covered in the Mach4 Operation Manual but most people don’t go looking for it.

Toolpath Preview

Did you know you can manipulate the view all the way down to the smallest detail of your toolpaths?

  • Quick View - The right-most buttons in a vertical column, below the VIEWS heading, are shortcuts to common angles. Mach4 refers to them as perspectives.

    • No matter how bad you screw up your view and get lost in the pixels, you can always use the Top “Default” button to return to the typical top-down view, nice and square. You can also double-click in the preview to return to the default. It may be zoomed-in too far, but that takes us to…
  • Navigation - You are free to move about the cabin…err…preview.

    • Rotate: Click and hold, then move the mouse around.
    • Pan: Hold the Control key and left-click to drag the view around. You can also click and hold both mouse buttons, then drag around.
    • Zoom: Easily zoom in and out with your mouse scrollwheel or by pinching with your trackpad. You can also right-click and hold, then drag your mouse fore and aft.
  • Squinting at Lines - The last button of the VIEWS column, titled Toolpath Settings, allows you to set the width of the lines in the Toolpath Preview! Crank em up!

    • Axis Line: Red lines representing your current X/Y position.
    • Path Line: White lines representing gcode toolpath to follow.
    • Soft Limits Line: Yellow dashed lines representing the machinable area, aka work envelope.
  • Regen Toolpath - Short for Regenerate Toolpath. Basically this redraws the preview with the latest information Mach4 has. Maybe you changed your X/Y zero or edited your gcode in an unusual order of operations - click Regen Toolpath and Mach4 will wipe the preview clean and draw it over again. I nearly wear this button out to ensure I’m always looking at an accurate preview.

  • DRO Auto Calc - This is handy for the old-school coolant flingers out there accustomed to having math operators available on their DRO. When enabled from the Operator menu, on the main menu bar at the top, you’ll get an inline calculator pop-up when you click on a DRO line for X-axis or Y-axis. Any maths you do gets entered as the new value on the DRO when you click Ent. To cancel the input and return what you had in the DRO previously, click Esc.

If you have other Mach4 tips that some of us might find useful, feel free to share. I feel like I’m always picking up new tricks watching YouTube or talking with folks. Maybe even sometimes reading the documentation (which you can get to easy from the Help > Documentation Folder menu item).

Have a productive week!