These instructions are assuming that you are using the Universal Lasers @ TechShop Chandler, and that you have taken the SBU and are familiar with how to operate the machine.
For more information on the TechShop or to schedule a class, visit techshop.ws
Step 1: Gather Materials
You will need painter's tape - 2" wide painter's tape would be easiest. You will also need an item to engrave. In this case, that will be a pint glass.
Step 2: Create the File
Measure the outline of the item that you are engraving. Draw that geometry into your file. The top of my pint glass has a diameter of 3.375", so I'm going to draw a circle with that same diameter. Make sure that the outline has a line color of RGB red, and set the line width to .001.
Since I am engraving on the bottom of the glass, which is a smaller diameter that the top of the glass, I will need to include that outline as well. This way, when the glass is upside down, I will use the top diameter to line it up to the jig, and the engraving graphic will be lined up perfectly. The bottom of the glass has a diameter of 2.25"
Once you have drawn the outline, place your graphic in the position it needs to be engraved in. Make sure that the graphic is in Black.
This will complete your file, and you should be ready to head to the laser cutter.
Step 3: Print File & Prep the Jig
Place strips of painter's tape along the bed of the laser cutter. The strips should be slightly larger that the outline of the item. At least 1" on all sides is a good buffer, but it doesn't have to be exact.
Once the tape is down, print the file.
Step 4: Cut the Jig
Locate the outline of the geometry so that the file on the bed so that it is centered on the tape. In the settings, set the material to Construction Paper. Set the material thickness to .01". In the manual settings, set the black to skip, click set & apply.
Start the file cutting. When it has finished cutting, remove the painters tape in the area where the item will be placed.
Step 5: Engrave the Item
Go back into the settings and choose the material and material thickness that are appropriate for the item you are engraving. In this case, I will be choosing borosilicate glass, and the material thickness will be 5.875" (the height of the glass). In the manual settings, select Black and set it to engrave, click set & apply. Then select the Red and set it to skip, click apply. Line up the item with the outline in the painter's tape. Start the file engraving. When it has finished engraving, remove the item and repeat the engraving with another item.