Replacement Lighthouse Lenses Made with CNC Machining

Services: CNC machiningPolishing
Material: PMMA (acrylic)
Lead Time: 13 days
Quantity: One set (29 prisms)

About The Project

The historic Charlotte-Genesee lighthouse is located in Rochester, NY on Lake Ontario and the Genesee River. To complete her 2014 restoration, 29 Fresnel lenses in a variety of sizes and geometries were needed. The lenses had to be fully functional, durable and provided at a reasonable cost for this volunteer-based restoration society.  Watch how these lenses were made in our video.

About The Client

“Artworks Florida was established in 1992 to aid in the restoration of the 1st order classic Fresnel lens in the St. Augustine Lighthouse, Florida. The lens was vandalized a few years earlier and the Coast Guard was scheduled to dismantle and remove the lens from the tower.  The Junior Service League of St. Augustine promised to raise the funds and find a way to restore the lens if they would be allowed to keep their historic lens in the tower. The lens was successfully restored and re-lit one year later. The following years Artworks Florida was involved in the restoration of several classic Fresnel lens at the Ponce Inlet Lighthouse, and numerous other Fresnel lens restorations around the country. In 2003 the design and production of full scale reproduction lenses began. These lenses are used as interpretive exhibits in museums, and used as private aids to navigation in many lighthouses around the country.” – from the Artworks Florida website.

Lighthouse Lens by Star Rapid
Fresnel lenses installed in the Charlotte-Genesee main lamp

CNC Machining

Fresnel lenses require a series of concentric, stepped graduations in order to function properly. Once the coordinates were programmed into our 3-axis CNC mill, it was easy to machine the acrylic to the exact tolerances required.

Care must be taken to control the speed and feed of the cutter head in order to achieve the highest possible finish quality necessary for a lens.

CNC machining of PMMA material


After machining the acrylic parts were very carefully buffed and polished by hand. Although this process is painstaking, it’s necessary to make optical quality clear prisms that have sharply defined corners and edges – something that would be impossible to do with machine polishing alone.

This degree of attention to detail is what sets us apart from our competition. Contact us for a free quotation to learn how we can apply the same careful workmanship to your next project.

Polishing PMMA material

Finish Product

One of the finished lenses