Biscuit Joiner

Overview

A biscuit joiner, or plate joiner, cuts matching crescent-shaped slots in the two faces of a joint so a flat oval of compressed beech, the biscuit, can be glued into both. The biscuit aligns the parts edge to edge and, once the glue swells it tight, reinforces the joint. It is a fast way to register butt joints, mitres, edge-glued panels and cabinet carcasses without the layout of dowels or mortises.

This is a standard handheld plate joiner. The Biscuit Joiner is driven by the Universal Motor, whose right-angle gear pair spins the Carbide Blade, a small carbide saw blade. The Plunge Mechanism mechanism pushes that blade out through the Faceplate to cut the slot and springs it back when released. The Fence & Depth Stops sets where the slot lands, the Dust Bag collects the waste, and the On/Off Switch arms the motor.

How it works

The Universal Motor is a compact universal motor; a right-angle gear pair turns its drive into the horizontal blade spindle. Power reaches it through the On/Off Switch and the Power Cord & Wiring. The Carbide Blade is a four- or six-tooth carbide-tipped disc on an arbor, sized so its swept arc cuts a slot the exact length and width of a standard biscuit.

To make a slot, the operator marks a centreline across the joint, sets the Fence & Depth Stops height so the slot will sit mid-thickness, and picks the biscuit size on the Depth Turret, that stop fixes how far the blade can travel and therefore the slot depth for a #0, #10 or #20 biscuit. With the Faceplate pressed flat against the work and aligned to the mark, the operator pushes the body forward. The Plunge Mechanism carriage slides on its guide rods, driving the spinning blade out through the faceplate and into the wood until the depth stop bottoms. Releasing the body lets the plunge return spring retract the blade fully behind the faceplate, the safe rest position.

The cut is repeated on the mating face at the same mark. Glue goes into both slots and on the biscuit; clamped up, the beech swells and locks the joint. The Dust Bag catches the fine chips so they do not pack the slot.