Crystal Cleaving Device

While working as a manufacturing engineering intern at Inrad Optics during the summer of 2018, I designed a crystal cleaving device in SolidWorks to turn a difficult and time-consuming operation, cleaving small crystals with a razor blade and a small hammer, into an easily repeatable process.

Motivation

Prior to the creation of the device, the crystal manufacturing technicians would manually cleave small cylindrical crystals by holding a thin razor blade up to the edge of a wall just above the crystal. Using their other hand, they would tap the razor blade using a small hammer, providing just enough force to cleave the crystal. Since the technicians had to hold the razor blade and the hammer while holding the crystal still with their other fingers, the operation proved to be exceptionally difficult to perform without accidentally chipping the crystal. Chipping of the crystal could be caused by a number of common issues, such as improper alignment of the razor blade, excessive force being applied to the crystal, or improper positioning of the crystal.

Solution

To alleviate these issues, I designed the crystal cleaving device, shown below, with a variety of features. During operation, the crystal would be placed in the v-block cutout and the aluminum stage, sliding on two shafts, would be gently lowered down until the crystal made contact with the L-shaped razor blade guard. The crystal manufacturing technician could then position and secure the shaft collars just below the aluminum stage to prevent it from lowering any further.

After the stage was lowered into position and the shaft collars were tightened, a small cylindrical weight, seen near the top of the renders below, would be dropped from a pre-determined distance above the aluminum stage. The weight would hit the spring-elevated shaft collar and apply just enough force to move the razor blade down onto the crystal and cleave it. For safety purposes, the stage utilized shoulder screws to prevent the razor blade from moving more than 1/16″ vertically.

Future Developments: In hindsight, the use of shaft collars to prevent the device’s aluminum stage from dropping was a poor design choice. Instead, the use of a leadscrew would have been a significantly better option for moving the aluminum stage up and down. That way, the operator would be able to position the stage simply by rotating a handle attached to the leadscrew without having to manually hold the stage and risk dropping it on the crystal below.