How to Engrave Cylindrical Objects with a Laser Rotary Attachment

Introduction

Flat engraving is only the beginning. A rotary attachment (also called a roller rotary or chuck rotary) lets your laser engrave tumblers, wine glasses, pens, baseball bats, and cylindrical objects with the same precision as flat work. Instead of moving the Y-axis, the rotary turns the object while the laser head tracks along the length. This guide covers rotary types, setup in LightBurn, job alignment, and the settings that separate clean cylinder engraving from distorted or blurred results.

What You Need

• Diode or CO2 laser with rotary attachment compatibility
• Roller rotary (most common for hobby lasers) or chuck rotary (for tapered or irregular objects)
• Cylindrical object: tumbler, glass, pen blank, or similar
• LightBurn software with rotary support enabled
• Masking tape or CerMark spray (for metal tumblers)
• Calipers for measuring object diameter
• Level surface and adjustable risers if needed

Step 1: Understand Your Rotary Type

Roller Rotary (Most Common)

• Two or four rubber rollers that grip and turn the cylinder
• Object rests freely on the rollers
• Best for: straight-walled cylinders like tumblers, cups, and bottles
• Limited on: tapered objects (they walk off the rollers) or very lightweight items

Chuck Rotary

• Three-jaw or four-jaw chuck grips one end of the object, like a lathe
• Supports tapered, conical, and irregular shapes
• Best for: wine glasses, vases, baseball bats, irregular items
• Requires: careful centering to prevent wobble at high RPM

How it works: The rotary connects to the Y-axis stepper driver on your laser. When the job runs, Y-axis commands rotate the object instead of moving the gantry. The laser head moves only in X (along the length of the cylinder) while the rotary handles the circumference.

Step 2: Install the Rotary Hardware

1. Power off your laser completely.
2. Disconnect the Y-axis stepper motor cable from the controller board.
3. Connect the rotary stepper cable to the same Y-axis port. Most rotary units use the same connector.
4. Place the rotary in the engraving area, aligned parallel to the X-axis rails.
5. Verify the rotary rollers or chuck turn freely and are level.

Alternative: dedicated rotary port. Some lasers (like Omtech, xTool, and Thunder) have a dedicated rotary port on the controller. If yours does, use that instead and set the controller to rotary mode in the machine settings.

Step 3: Measure and Enter the Object Diameter

1. Use digital calipers to measure the outer diameter of the cylinder at the engraving location.
2. Note this value precisely. A 0.5 mm error in diameter causes visible stretching or compression in the engraved image.
3. In LightBurn, go to Laser Tools > Rotary Setup.
4. Enable rotary mode and select your rotary type: Roller or Chuck.
5. Enter the diameter you measured in the Object Diameter or Circumference field.

Step 4: Configure Rotary Steps per Rotation

The steps-per-rotation value tells LightBurn how many motor steps equal one full turn of the object. This depends on your rotary unit's gear ratio and your laser's stepper driver settings.

1. Start with the manufacturer's default value (common values: 3600, 4000, 5000, or 10000 steps per rotation).
2. Run a test: draw a 50 mm tall rectangle in LightBurn and frame it. Mark the starting point on your cylinder with tape.
3. After framing, the mark should return to the exact same position. If it stops short or overshoots, adjust steps per rotation:

• Overshoot (more than one full rotation): increase steps per rotation
• Undershoot (less than one full rotation): decrease steps per rotation

Formula method: If you know your rotary's gear ratio and your laser's steps per mm on the Y-axis, calculate: steps per rotation = (motor steps per revolution * gear ratio) / drive roller diameter ratio. Most manufacturers provide this value in the manual.

Step 5: Prepare the Cylindrical Object

1. Clean the surface with isopropyl alcohol to remove oils and dust.
2. For stainless steel or coated metal tumblers, apply a thin, even coat of CerMark or similar laser marking spray. Let it dry completely.
3. For glass, apply a thin layer of dish soap or use the wet paper towel method to prevent thermal shock cracking.
4. For powder-coated tumblers, no prep needed unless the coating is dirty.
5. Place the object on the rotary rollers or in the chuck.

Alignment check: Spin the object by hand. It should turn smoothly with no wobble. If it wobbles, it is not centered. Adjust the roller position or chuck jaws until the object spins true.

Step 6: Set Up the Job in LightBurn

1. Import or create your design. Remember that the Y-axis in LightBurn now represents the circumference of the object.
2. Set the job height to no more than the measured circumference of your object. If your design is taller than the circumference, it will overlap itself.
3. Position the design so it starts where you want it on the cylinder.
4. Use the Frame button to trace the outline. Watch the object rotate and the laser head move. Verify the framing path looks correct and nothing collides.

Important: Enable "Return to finish position" or note the starting position so the object returns to the home orientation after engraving.

Step 7: Set Power and Speed for Cylinders

Cylinder engraving uses similar power settings to flat engraving for the same material, with two adjustments:

• Reduce speed by 10-20% on roller rotaries. Slippage between the rollers and the object causes slight positional errors at high speeds. Slower speeds minimize this.
• Maintain consistent focus. The laser focal point must stay at the same distance from the surface as the object rotates. For roller rotaries, the object centerline stays at a fixed height. For chuck rotaries, measure the radius and adjust the Z-height accordingly.

Starting points by material:

• Powder-coated tumbler (20W diode): 1000 mm/min, 85% power, 1 pass
• Stainless steel with CerMark (20W diode): 800 mm/min, 90% power, 1 pass
• Clear glass (40W CO2): 200 mm/min, 35% power, 1 pass with wet paper
• Wood pen blank (10W diode): 3000 mm/min, 75% power, 1 pass

Step 8: Run the Job and Monitor

1. Start the job at low power (10-15%) on your first attempt to verify alignment without burning.
2. Watch the first full rotation. Check that the image does not shift, stretch, or compress.
3. If the image looks stretched horizontally (around the circumference), your steps-per-rotation value is wrong or your diameter measurement is off. Recalibrate.
4. If the image has gaps or overlaps at the seam, adjust the object diameter value in LightBurn by 0.1 mm increments.
5. Once alignment is verified, run the job at full power.

Critical: Never leave a rotary job unattended. Objects can slip off rollers or work loose in a chuck, causing the laser to fire at the rotary mechanism or into open air.

Step 9: Remove and Clean

1. Wait for the object to return to the start position.
2. For CerMark-marked metal: rinse under water and scrub with a Scotch-Brite pad to remove excess spray. The mark is permanent.
3. For glass: rinse off the soap or paper towel residue.
4. For coated tumblers: wipe clean with a dry cloth.

Tips for Perfect Cylinder Engraving

• Test on a scrap tube first. PVC pipe or a cheap aluminum can with the same diameter lets you dial in settings without risking an expensive tumbler.
• Weight lightweight objects. A wine glass on a roller rotary may slip. Tape a counterweight to the opposite side or use rubber bands around the rollers for grip.
• Use index marks for multi-color or multi-step jobs. Mark the start position with tape so you can re-align exactly if doing multiple operations.
• Check roller grip tension. Loose rollers cause micro-slippage that blurs fine text. Tighten the roller spacing or add a rubber band for friction.
• Focus is critical on curved surfaces. The focal point changes slightly across the curve. Keep your designs within the center 120 degrees of the cylinder face for sharpest results. Avoid wrapping text around the full 360 unless using a chuck rotary with excellent centering.

Troubleshooting

• Image stretched or compressed: Wrong object diameter or steps-per-rotation. Re-measure and recalibrate.
• Blurred text: Object is wobbling. Center the chuck better or check roller alignment.
• Image split at the seam: Circumference value is slightly off. Adjust diameter in 0.1 mm steps.
• Laser not firing in the right place: Rotary not enabled in LightBurn. Verify Rotary Setup is active.
• Object fell off mid-job: Roller spacing too wide, object too light, or speed too high. Add weight, reduce speed, or use a chuck rotary.

Conclusion

A rotary attachment turns your flat laser into a cylindrical engraving machine capable of personalizing drinkware, producing custom pens, and marking industrial tubes. The setup—hardware connection, diameter measurement, steps-per-rotation calibration, and LightBurn configuration—takes about 15 minutes once you learn it. After that, every cylinder job becomes as routine as engraving a flat board, and your product offerings expand dramatically.