Compact optical grinding and polishing machine

A remarkable new portable machine for grinding and polishing optics has been unveiled by Christo, an amateur telescope maker with a passion for innovation and craftsmanship. Designed specifically for DIY mirror making and small-scale optical fabrication, this compact device fills an important gap in the amateur astronomy community, where large, stationary polishing machines have long been the norm.

Compact optical grinding and polishing machine revives family legacy and advances DIY telescope making

The idea for the machine was sparked by Christo’s firsthand experience in telescope building, particularly with Cassegrain-type systems that demand precise work on secondary mirrors, corrective lenses, and auxiliary optics. Motivated by the need for a transportable, high-RPM solution and inspired by memories of working alongside his late father, Christo has transformed a dormant family project into a highly functional tool for modern hobbyists.

The portable optics machine traces its origins to a project Christo began with his father a decade ago. After his father’s passing, the partially built machine was set aside. Recently, with enhanced CAD skills honed through SolidWorks and the successful creation of a custom CNC router, Christo revisited the project. Rediscovering the old components in the attic, he realized he now had the tools and expertise to complete the work his father started.

The machine features Zeiss-type kinematics, chosen for their compact form and ability to generate varied stroke patterns. The original framework included bearing mounts for three axes, an angle iron housing, a steel worktable, and a partial faceplate. Initially designed for a single DC brushed motor with chain-driven transmission, Christo modernized the system by integrating two independent brushless motors, each connected via toothed belt drives to separate worm gear reducers.

To optimize functionality, Christo engineered adjustable lever offsets using stainless steel turnbuckles and threaded rods with opposing threads, enabling quick and precise adjustments. After experimenting with gear ratios, he finalized a 1:90 ratio for the faceplate and 1:60 for the arm, striking the right balance between speed and control.

Moving beyond the original steel-based design, Christo opted for a full aluminum construction, significantly reducing weight while maintaining strength. The work surface is built from 10 mm Al2017 aluminum plate, while the frame and other panels use Al6061 and Al6068, ensuring durability and precision. Structural components were fabricated from 20×20 mm aluminum profile, all meticulously machined in a dedicated milling session.

The unveiling of this portable optics machine has drawn positive feedback from fellow enthusiasts, many of whom recognize the potential to improve DIY mirror making processes. Community members have shared similar experiences, particularly with the Zeiss configuration’s ability to balance spin polishing efficiency and surface accuracy.

Christo’s achievement not only revives a cherished family project but also contributes a practical, affordable, and adaptable tool to the amateur telescope making community, one that addresses long-standing challenges in portability, speed control, and component versatility.

With initial testing complete and key mechanical systems refined, Christo plans further updates and potential enhancements, such as the addition of a second eccentric for greater movement variability. The project stands as a testament to innovation, perseverance, and the enduring spirit of hands-on astronomy.

For more details, watch the machine in action in the videos below.

Offset adjustment

Milling the mount for the gearbox and the electric motor

Testing 2 motors & reductors