Core box planer
A core box planer is a hand plane for the preparation of semi-circular grooves . In the past it was used, among other things, to fillet wooden rain gutters.
Thales theorem
The core box plane is the "planed" proof of Thales' theorem . This means that all angles on the semicircular arc are right angles. The planer sole tapers at an angle of 90 °, so that the planar cross-section is the shape of a right-angled triangle. The planing creates a semicircular groove.
Individual evidence
- ↑ Article in the specialist journal for woodworkers from 1921, retrieved from "KLEINES WERKZEUGMUSEUM" on the website holzwerken.de .