Glass Tumbler with Wooden Lid and Heart Molecule Design

Note: Since glass is transparent, standard diode lasers (like the D1 Pro or M1) pass right through it without marking it. You must "mask" the glass first. If you are using a CO2 laser (like the P2), you can often engrave directly, but masking still helps prevent micro-fractures (chipping).

Phase 1: 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.

Phase 2: 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.

Phase 3: 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.

Phase 4: 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.

Phase 5: 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.