A fischertechnik model of an industrial sawmill, built to actually do something useful: cut balsa wood boards to precise widths.

The saw unit

The centerpiece is a Kreissägenaggregat - a twin-blade circular saw assembly where both blades can be shifted horizontally relative to each other. By adjusting the gap between them, you define the width of the resulting board. The two outer strips are the cutoffs.

The plant

Boards are fed in from one side. Before reaching the blades, they pass through a centering station that aligns the board along its centerline and - as a side effect of the centering movement - measures its width. That measurement goes straight to the control software, which uses it to calculate a valid cut width and sets the blade gap accordingly.

After the saw, a second clamping and feed unit on the exit side takes over, pulling the boards through and then releasing them. The final step separates the main product from the left and right cutoffs.

The whole sequence - centering, measuring, blade adjustment, clamping, feeding, cutting, separating - runs without manual intervention.

Control

Everything is driven by a Raspberry Pi with motor hats. Sensors detect board position and drive the logic for each station. The control software ties it all together: it reads the width measurement from the centering step, determines the target cut width, and moves the saw blades before the board reaches them.