Valentine’s Day Iced Coffee Glass

Preparation & Masking

1. Clean the Glass: Wipe the glass down with isopropyl alcohol to remove fingerprints and oils.
2. Mask the Glass (Crucial for Diode Lasers):
   • Method A (Best for Diode): Spray the engraving area with Cold Galvanizing Compound (a spray paint found at hardware stores) or black tempera paint/chalk spray. The laser heats the pigment/metal, which transfers heat to the glass to create the fracture.
   • Method B (Best for CO2/P2): Wet a single layer of paper towel and smooth it over the glass (no air bubbles). This keeps the glass cool and prevents shards from chipping off.
3. Install the Rotary Attachment:
   • Plug your RA2 Pro (or similar rotary) into the machine.
   • Set it to Chuck Mode (gripping the glass) or Roller Mode (resting the glass), depending on the shape. For a straight-walled whiskey glass, Rollers are fine. If it tapers or is heavy, Chuck mode is safer.
   • Tip: Use the leveling tool (the little spirit level) to ensure the surface of the glass is perfectly flat horizontally. If the glass is tilted, the laser focus will drift.

xTool Studio Setup

1. Connect & Select: Open XCS and connect your machine. Select "Laser Cylindrical" mode on the right-hand panel.
2. Input Diameter: Measure the diameter of your glass (in mm) and enter it into the software so the rotary spins at the correct speed.
3. Import Design:
   • Import your .xcs file into Studio
   • Rotate the design 90 degrees if necessary (depending on how your rotary is oriented—usually the top of the glass faces left).
4. Settings (Starting Point):
   • These vary by machine wattage, but here are safe starting points for a 10W Diode:
   • Power: 100%
   • Speed: 50–70 mm/s
   • Lines per cm (LPC): 100–120 (Too high causes heat stress/cracking; too low looks faint).

For CO2 (P2): Lower power (15-20%) and higher speed (150+ mm/s) is usually sufficient

Focusing & Framing

1. Focus the Laser:
   • Move the laser head over the highest point of the glass curve.
   • Use the kickstand lever (D1/M1) or the auto-measure (P2) to set the focus distance right on top of the glass surface.
2. Framing:
   • Click "Framing" in XCS.
   • Watch the laser head move and the glass spin.
   • Ensure the design isn't hitting the heavy rim at the bottom or the lip at the top. It should be centered in the clear area.

Engraving & Cleanup

1. Run the Job: Put on your safety goggles (glass reflects laser beams!) and hit "Start."
2. Cool Down: Let the glass sit for a minute or two after the job finishes. It will be hot.
3. Remove Masking:
   • Take the glass to a sink.
   • Use a scouring pad (like a green Scotch-Brite) or a "Magic Eraser" with water to scrub off the paint or galvanizing spray.
   • Note: The paint might look stubborn, but the laser has permanently etched the glass underneath. Once the paint is gone, you will see the frosted white look.

Quality Check

• Check for "Shards": Run your finger gently over the engraving. If it feels extremely rough or sharp like sandpaper, you may have used too much power or too slow a speed (causing deep fracturing).
• Solution: lightly sand the engraving with high-grit sandpaper (2000 grit) or steel wool to smooth it out for the customer.