MPCNC Tangential Knife

thingiverse

It appears to be a set of instructions for using Gcodetools to generate gcode for a tangential cutter on an MPCNC CNC machine. Here are the key points: **New Parameters** 1. Knife lift threshold angle: Only lifts the knife if the material thickness/angle requires it. 2. 4th axis command: Allows generation of gcode with A commands substituted with E (see firmware below). 3. Turn feed: Adds an FXXX gcode command to the turns, so turn speed is controllable. **Firmware** A small modification is required for best results with the standard MPCNC supplied Marlin firmware. In configuration.h, comment out the following lines: ``` #define PREVENT_LENGTHY_EXTRUDE #define EXTRUDE_MAXLENGTH 200 ``` This will prevent over extrusion detection and allow the E0 steps per mm value to be set correctly. **Setup** 1. Install Gcodetools from GitHub. 2. Set the tool to be tangential knife in Inkscape: * Extensions -> Gcodetools dev -> Tools library-dev -> tangient knife -> Apply * Adjust the values as needed: + Lift knife at corner: set to how much lift you want in addition to current cut depth + 4th axis command: override to E (from A) for MPCNC Marlin + Knife lift threshold angle: set the turn angle in degrees above which turns will have a lift. Eg: 45 + Depth step: this is the maximum depth per cut 3. Create orientation points: * Extensions -> Gcodetools dev -> Orientation points-dev -> Z-depth -> Apply 4. Generate the gcode: * Extensions -> Gcodetools dev -> Path to Gcode-dev * Set the directory and options as needed, then apply. **Running the Gcode** 1. Check that the E0 steps per mm value is set correctly by issuing a g1 e3600 command (10 full turns) and checking that 10 turns happen and the final angle matches the initial angle. 2. Run the generated gcode directly on your MPCNC Marlin firmware. Note: This instructions assume you have already installed Gcodetools from GitHub and have a basic understanding of how to use Inkscape and the MPCNC CNC machine.