Here are a few pictures of the CBC machine shop milling a pocket into a piece of 1/4″ thick Quartz glass. Although the Chemistry department does have a well equipped glassblowing shop, their tooling is designed to handle heating, blowing, and tempering of glassware. When it comes to machining different materials, this is an area of expertise for the CBC Machine Shop.
Glass, much like ceramics is one of the harder materials to machine. In order to put this .010″ deep pocket into the quartz plate, a diamond coated, solid carbide end mill had to be used.
No 3 factors are more critical to determining the finish of a machined part than Speed, Feed, and Temperature. This is much more important when machining tougher materials like glass. The 2-axis CNC milling machine, recently purchased by the chemistry department, allowed for precise control of the speed ind feed via the machine’s servo motors. The temperature was controlled by using a steady flow of flood coolant on the part. Because harder materials like glass can crack easily, the speed was increased, while the feed was retarded to 0.5″ per minute. This resulted is a slow, controlled cut, which created a fine glass powder as opposed to large glass chunks.