The polishing of precision-cut gems isn’t just for professionals with access to vast machine shops full of equipment. While faceting equipment can run into the thousands of dollars, it is possible to create your own machine at home for a fraction of that cost. The basic parts of your faceting machine should include the lap, or grinding wheel, along with a cheap, portable template faceter to replace the more expensive and labor-intensive fixed mast.
Building the Template Faceter
Cut aluminum sheeting into a regular hexagon 3 1/2 in. in diameter, using a bandsaw.
Drill a hole in the center of the hexagon with the carriage bolt.
Fit the aluminum jamb peg through the hole.
Fasten the jamb peg firmly to the base of the hexagonal sheet with the thumb nut.
Attach a gem to the end of the jamb peg with wax or glue.
Constructing the Lap Wheel
Place the metal bowl on the tooling plate and drill central holes through both.
Insert the spindle through the tooling plate up through the center of the bowl, and fasten it with a nut.
Place a motorized grinding wheel with AC hookup on the spindle so that the resulting mechanism can spin freely. Make sure that there are at least several millimeters of space between circumference of the lap wheel and the circumference of the bowl.
Please note that a makeshift template faceter will only facet stones to certain parameters. A fixed masthead allowing for variable angles and height requires a far more involved period of machining and construction.
Other items, such as a potter's wheel, can be adapted for use as the grinding lap wheel in your faceter.
Always have a liquid lubricant on hand for use on the grind wheel. Faceting produces a great deal of dust, which can clog your machine and which is harmful if inhaled.
Your makeshift faceter will not work with harder stones, such as diamonds, which require specialized equipment.