Engraving beautiful, seamless designs on curved surfaces like stainless steel tumblers, mugs, or glasses seems tricky with a standard laser engraver — but that's where the rotary attachment (also called a rotary axis or rotary tool) comes in. This essential accessory transforms your flat-bed laser into a cylindrical engraving powerhouse, enabling perfect 360-degree wraps without distortion or manual repositioning.

How a Rotary Attachment Works

In normal flat engraving, the laser head moves in X and Y axes while the material stays still. For curved objects, this causes issues: the surface curves away from the focal point, leading to blurry or uneven results.

A rotary attachment solves this by rotating the tumbler synchronously with the laser's movement:

1. The tumbler is securely mounted on the rotary.
2. The rotary connects to the machine (often replacing or overriding the Y-axis motor).
3. In software (like LightBurn or xTool Creative Space), you enable "Rotary Mode" and input the tumbler's diameter or circumference.
4. The software "unwraps" your design into a flat layout, but the rotary translates Y-axis movement into rotation.
5. As the laser moves left-to-right (X-axis), the tumbler spins precisely, keeping the surface perfectly under the beam for crisp, continuous engraving.

This creates flawless full-wrap designs, text, or patterns that look professional and dishwasher-safe.

Types of Rotary Attachments: Roller vs. Chuck

There are two main types, each suited to different tumblers and needs:

Roller Rotary

• How it works: The tumbler rests on two (or more) motorized rollers that spin it via friction. Adjustable wheel distance accommodates different diameters.
• Pros: Simple setup, great for long or heavy uniform cylinders (like straight tumblers or bottles), affordable, and handles larger items easily.
• Cons: Can slip on tapered shapes, handled mugs, or during deep engravings; not ideal for irregular objects.
• Best for: Standard powder-coated tumblers in high volume.

Chuck Rotary

• How it works: A three- or four-jaw chuck (like a drill chuck) grips one end of the tumbler tightly, with a tailstock supporting the other for stability.
• Pros: Rock-solid grip prevents slippage, excellent for tapered tumblers (e.g., Yeti-style), handled mugs, or irregular shapes; higher precision for detailed work.
• Cons: Slightly more setup time, limited to objects that fit the jaw range (often smaller max diameter).
• Best for: Professional results on varied or tricky tumblers.

Hybrid Options: Some advanced rotaries, like the xTool RA2 Pro, combine both in a 4-in-1 design (roller, chuck, sphere, and ring modes) for ultimate versatility.

Tips for Success with Tumblers

• Measure accurately: Input the exact diameter in software for distortion-free wraps.
• Secure the tumbler: Clean surfaces, use masking if needed, and test for slippage.
• Focus properly: Many machines have auto-focus or curved surface tools.
• Test settings: Start with lower power/speed to avoid burns or weak marks.
• Compatibility: Ensure your engraver supports rotary (most modern diode/CO2/fiber do).

A quality rotary attachment unlocks endless custom tumbler possibilities — from personalized gifts to profitable Etsy listings. It's truly the game-changer for curved engraving! If you're ready to dive in, pair it with a compatible machine and start creating.