3D Milling on Zünd Cutters with Grasshopper (HPGL)

Freeform Surfaces Instead of Flat Cuts

Zünd digital cutters are built for cutting and 2D routing. Continuous 3D surfaces – where the router moves in X, Y and Z at the same time – are not part of the standard workflow. With LARGER.slicer, our Grasshopper toolkit, they are: the plugin generates 3D milling toolpaths in Grasshopper and exports them as an HPGL/PLT file that the Zünd runs directly.

3D simultaneous milling on the Zünd G3 at FH Münster – toolpath and HPGL file from LARGER.slicer.

How It Works

In LARGER.slicer, the CNC Program component takes a 3D geometry from Rhino – a Brep or a mesh – and calculates a zigzag toolpath (boustrophedon) across the surface. Every point of the path carries its own Z height, so the router follows the freeform surface continuously instead of milling in flat steps.

Zigzag 3D milling toolpath of an MSA relief in Rhino with the generated HPGL code in Grasshopper — Zigzag toolpath in Rhino and the generated HPGL code in Grasshopper.

The exported PLT file already contains everything the machine needs: tool selection, spindle speed, vacuum control, Z positioning, extraction height and underlay compensation.

Workflow

Reference the 3D geometry in Grasshopper and check that it fits the working area.
Set material thickness, pass depth, stepover, tool and spindle speed.
Generate the toolpath with the CNC Program component and check it in the Rhino viewport.
Export the HPGL/PLT file.
Load the file in Zünd Cut Center, fix the material with vacuum, calibrate the tool height and start the job.

From Toolpath to Relief

Zünd router milling a freeform relief surface into a wooden board — The router follows the freeform surface in X, Y and Z at the same time – the result is a smooth relief instead of flat steps.

Detail of the 3D-milled freeform surface with lettering — The router follows the freeform surface in X, Y and Z at the same time – the result is a smooth relief instead of flat steps.

Tested on the Zünd G3 L-2500 at FH Münster

Working area 1800 × 2500 mm, working height up to 50 mm
Routing module RM-A with 1 kW spindle and automatic router bit changer
Grasshopper template and quick start guide included in the LARGER.slicer download

Zünd G3 digital cutter at the MSA, FH Münster — The Zünd G3 L-2500 at the MSA, FH Münster.

Zünd G3 L-2500 modelled in Rhino next to the LARGER.slicer Grasshopper definition — The Zünd G3 L-2500 as a Rhino model, next to the LARGER.slicer Grasshopper definition.

Typical applications are reliefs, textured panels, mould and prototype surfaces – anything that needs a smooth 3D surface rather than a flat cut.

Using a Zünd in Your Workshop?

Many shopfitters and interior workshops already have a Zünd cutter. We adapt the workflow to your machine, tools and materials – so you can use it for 3D surfaces as well.

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