Swiss Designer's Floating Planer Gantry Flattens Slabs Fast

A Swiss industrial designer has engineered a custom system for flattening live-edge slabs that rethinks the traditional router gantry. The system uses a floating hand planer and an adjustable screw bed to work faster and with more sensitivity to the wood's surface.

Sebastian Pfirter-Wiget, a draftsman and industrial designer, designed the machine. He shared details of the build with a woodworking instructor after seeing posts about a standard router-based workshop. His approach tackles two main problems: the rigid cutting action of a router sled and the time-consuming process of shimming a twisted slab.

The Floating Parallelogram Mechanism

The core innovation is how the cutter is suspended. Instead of a fixed-depth router bit, Pfirter-Wiget cradles a Makita portable electric hand planer inside a floating parallelogram carriage. This four-bar linkage, made of wood, allows the tool to rise and fall in response to the wood's topography.

The planer is secured in an open plywood cradle with contoured side cheeks. A heavy-duty threaded rod passes through a 10 mm hole in the planer's housing and the cheeks, locking it in place. This entire cradle is hung within a sliding H-frame made from T-slot aluminum extrusions. The frame moves along the walls of a main box bed.

In operation, the mechanism lets the planer ride over high spots, skimming light ribbons off the peaks. Gravity pulls the cutter lower as high spots are removed, until it reaches a preset stop, establishing a flat plane. The user moves the H-frame laterally between passes to cover the slab's full width.

Pfirter-Wiget notes that taking 1 mm per pass allows a board side to be set up and skimmed flat in about 10 minutes. After one face is flat, the board is flipped and the second face is planed parallel before a final pass through a thickness planer.

The Adjustable Screw Bed Support

To support warped slabs without shims, Pfirter-Wiget built a bed with dozens of grub screws. He calls this "screwing a topography." Using a cordless drill with a hex bit, he quickly adjusts individual screws up or down to cradle the slab's irregular underside, locking it in place rapidly.

Sourcing and Testing with Swiss Ash

The wood used in testing came from a 135-year-old ash tree from Pfirter-Wiget's family forest in Switzerland. He cited the tree's age and shady valley location for producing dense, high-quality wood. He also noted the timber-management context, as Swiss ash faces dieback from an invasive fungus, making harvesting mature trees timely.

Real-world testing on this dense hardwood revealed the system's demands. Pfirter-Wiget admitted pushing an old, used Makita 1923B planer too hard with full-width cuts, which burned out the motor windings. He repaired it with a $14 aftermarket rotor. He also acquired a second used Makita 1923B for about $50 as a backup.

He emphasized the design's adaptability, stating that any electric hand planer could work if building from scratch. The vintage model he used shares parts with the modern Makita KP0800. The breakdown highlighted the economy of servicing such classic tools.