Grinding/Polishing machine

This Computer Numerically Controlled (CNC) grinding / polishing machine serves 3 purposes:

Overview

The CNC machine can grind and polish blanks of up to 1.4m diameter. I built it out of steel stock and various mechanical components as described in this page.
Wide view of the ginding/polishing machine. The plastic film around the machine, and the metal hose under, prevent dust buildup during plaster mold grinding, and keep dust away for polishing.
Top view of the CNC machine.
Dust evacuation duct. There is a 120VAC fan inside the duct to suck air from the top of the machine to the bottom and send it outside the building through a hole in the floor.

Mechanical design

Left X axis bearing. A linear ball bearing is visible in the bottom. The ball screw, driven by a stepper motor, is used to drive the X axis. The Y axis motor and bearings are visible in the background.
A chain keeps the 2 sides of the X axis in sync.
Y axis stepper motor driving the Y axis ball screw (not visible - behind the brown plastic cover).
Y axis linear ball bearings (bottom) and ball screw (top).
Z axis.
Machining tool for the wax. This tool was made by cutting a pizza cutting wheel in 4. It's a cheap way to make a large radius of curvature tool, which is ideal to shape the wax.

Old pictures of the machine

These pictures show an early version of the machine, with conventional screw instead of ballscrews, smaller steppers, and single side drive for the X axis.
Wide view of the ginding/polishing machine.
Grinding head. The black plastic pipe is for dust control, and is connected to a modified vacuum cleaner outside the building.