I am an aspiring glass artist that wanted to take advantage of the laser engraver at the local TechShop. I had an idea to embed a laser etched image in the center of a glass marble using the Epilog laser engraving tool. This is a pretty cool project if you have access to a small torch for glass work, and of course a laser engraver. In order to have access to this tool, I made it at TechShop (www.techshop.ws).
1) Laser Engraver (all TechShop locations)
2) Access to and training on a glass torch (some TechShop locations)
3) Graphite marble marver (unless you are good at making glass marbles)
4) Mashers or graphite pads for mashing molten glass
5) Tile cutters (or other tool for cutting glass rod)
6) Kiln for annealing the final marble
7) Dydidium glasses (to protect your eyes from sodium flare when hot-working the glass)
Associated TechShop Classes:
1) LAS101: Laser Cutting and Etching SBU
2) ART104: Making Glass Beads with a Flaming Torch
1) Two ~2' rods of CoE 104 glass (others may work, but laser engraver was compatible with soda glass)
Step 1: Making a Cabachon
This first step involves making the "canvas" which you will use to etch the image upon. To do this, strike up the glass torch and put on your dydidium safety glasses. Now slowly heat the clear glass rod at the outside of a neutral flame. Rotate the glass rod continuously as you warm it up to evenly distribute the heat. As the glass warms up begin bringing it into the sweet spot of the flame and gather a small sphere of molten glass. Once you have gathered a ball ~1/4" in diameter use a pair of mashers or two graphite pads to flatten the ball into the cabochon, or disk. Flame polish the cabochon to remove the surface texture created when you mashed the glob of glass. Now place the cabochon into a kiln to anneal it, or take you chances allowing it to cool slowly to room temperature.
Step 2: Etching the "canvas" Using the Laser Engraver
As if melting and manipulating glass wasn't cool enough, now you get to use a laser on the piece of glass you've bent to your will. First use the tile cutter or other glass cutting tool to remove the cabochon you made in step 1 from the rod it was formed with. Leave ~1/4" of rod at the end for the later steps. Using Adobe Illustrator or your preferred illustration software import the design you want to engrave and embed inside your marble. Measure the diameter of your cabochon and make a note of this value. Now you must resize the canvas within the illustration software to match the diameter of your cabochon. Now you can place the cabochon at the home location of the laser engraver and print the pattern making sure you properly define the canvas dimensions in the print dialogue box. Be sure to align and calibrate the laser before printing. I also recommend performing a practice run first with the etching laser disabled (usually just open the door while printing) to make sure the laser printer is printing in the right location. Now you can print your design onto the cabochon and proceed to the next step.
Step 3: Making the Marble
Once you have printed your design on the cabochon it is time to encase the disk within a sphere of glass to make the marble. First you will want to reattach a glass rod (you can use the one you made the cabochon from) with the torch. Be sure you are wearing your dydidium safety glass again! Once you have done this you should slowly reheat the disk in a neutral flame being careful not to melt down the etched design. The purpose here is to warm the glass in preparation for receiving a hot glob of glass without cracking. While you are keeping the cabochon warm in the outside of the flame begin forming a gather ~1/2" in diameter with the second glass rod. Once you have gathered the right amount of glass, allow it to cool to a point just above the working temperature (slightly glowing) and proceed to place to glob of glass onto the face of the cabochon that contains the etched design. be sure to cover the entire pattern with the hot glass or you may loose some of the design in the final step. You may need to use a graphite marver to smash the glob on the face of the disk. Now repeat this same procedure, gathering ~1/2" of molten glass and applying it to the back side of the cabochon.
Step 4: Forming and Finishing the Marble
This is the final step in this tutorial. Here you will slowly heat and rotate the aggregation of glass as part of the basic process of forming a marble. You may use a marble marver or any other tool for this step. Be very careful not to heat the glass too much or the design will suffer from distortion. Continue to add heat to the glob slowly transforming it into a sphere until you are satisfied with the shape. Finally use the tile cutters to remove the marble from the glass rod (or if you are skilled, break of the cold seal you used to attach the cabochon to the glass rod) and fire polish the scar from where the rod was attached. Allow the marble to cool slightly below the working temperature and place it into a prepared kiln for annealing. Once the marble comes to room temperature you will have an awesome marble that you can show off to your friends impressing them with your skill and daring!