Wilhelm Bothner WB15 Optical Curve Generating Lathe 60° Swivel 150mm Stroke 220V

Wilhelm Bothner WB15 Optical Curve Generating Lathe 60° Swivel 150mm Stroke 220V

The Wilhelm Bothner WB15 is a precision optical curve generating lathe built by Wilhelm Bothner & Co., Masch. u. Zahnradfabrik, Braunschweig, Germany — a specialist German manufacturer of machine tools and gear-cutting machinery. This type of machine is designed to generate accurate spherical and aspherical curved surfaces on optical elements such as lenses, prisms, and glass blanks by driving a rotating workpiece against a precision-controlled cutting or grinding tool along a defined radius path. The WB15 features a 60° swivel range and a 150mm stroke, providing the geometry range needed for a wide variety of optical surface radii. Power is 220VAC via a dual-motor arrangement — a driving motor for the main curve-generation mechanism and a separate work motor for the workpiece spindle.

Specifications & What's Included

• Manufacturer: Wilhelm Bothner & Co., Braunschweig, Germany
• Model: WB15
• Machine type: Optical Curve Generating Lathe
• Swivel range: 60°
• Stroke: 150mm
• Power: 220VAC
• Drive: Dual-motor — Driving Motor and Work Motor
• Control panel: Driving Motor On/Off pushbuttons, Work Motor On/Off pushbuttons, Pole Switch for Driving Motor (2-speed)
• Internal mechanism: Worm and helical gear train with large bronze worm wheel; red-painted internal gearbox housing
• Curve-generating cam mechanism visible in top compartment with adjustable toolholder tray
• Precision spindle with graduated micrometer collar (scale visible to 150–180mm range)
• Spindle assembly with dual cable connections and precision coupler
• Integrated air/oil lubrication system with pressure regulator, filter bowls, and pressure gauge on side panel
• Secondary lubrication/filtration panel with oil reservoir and gauge
• Floor-standing pedestal cabinet construction on original pallet
• Accessory tray with toolholders present (see photos)

Applications

Optical curve generating lathes of this type were the standard production tool in precision optics manufacturing from the mid-20th century onward, used to grind and generate spherical surfaces on optical glass blanks — the foundational step in producing camera lenses, telescope mirrors, microscope objectives, surveying instruments, and military optics. The curve-generating principle works by swinging the cutting or grinding tool through a precise arc radius, producing a spherically accurate surface without requiring a form-ground wheel. The WB15's 60° swivel and 150mm stroke make it suitable for generating a broad range of surface radii on small to medium optical elements. Machines of this class were historically found in optical workshops at instrument manufacturers, defense contractors, university optical shops, and precision optics job shops. The Bothner name was well regarded in German optical and gear machinery, and WB-series lathes saw use in European and international optics facilities from the 1950s through the 1980s. Today, working examples are sought by small optics shops, optical instrument restorers, and hobbyist opticians who need a proven mechanical curve generator for custom lens and mirror work.