CNC Glass Grinder

I needed glass mitered to a very particular angle. Most glass shops can only do bevels up to 45 degrees. Here is a video of glass grinding in action:



My initial solution was to build a jig which let me grind back and forth on a hobby glass grinder to get that angle. Afterwards, the glass looked like this:



With a new CNC glass grinder, I can now create miters that look a lot smoother. I can turn on the grinder, have it go back and forth slowly, and come back to it when it is finished to reload it.


A hobby grinder is fixed in the middle. On the left hand, a pane of glass is clamped to a sloped jig made of acrylic. This ensures that the glass is ground to the proper miter. The acrylic is mounted to a C-beam gantries on the left and right


The CNC is just a 1-axis machine for now. The plate is moved back and forth against the fixed grinder. I can control the speed and how many passes are made by writing G-code scripts.


I've got ad-hoc spray shields. In the longer term, I will want to mount something more permanent directly onto the extrusion. Both the C-beams are mounted with the inner gantries pointing away from the grinder. This prevents dried sand buildup on the rails which was a problem with an earlier jig.


A full C-beam actuator kit on one side moves the glass back and forth. The gantries on the other side simply provide extra support and rigidity as they move back and forth on their rails.

The jig is held together with acrylic glue and everything else is bolted.



I put two C-beam gantries on each side connected together by a 20 x 80 V-slot. This may be overkill.


So far the quality seems to be much better and it halves the work required. I still need to wash and clean every pane of glass after grinding.

For a bit more discussion and a photo of the very first glass grinding jig that started me on the path to this build, click here.