Rotary setup

A rotary attachment replaces the Y axis (or sometimes a separate axis) with a turntable so the laser can engrave around a cylindrical object. From the laser's perspective, the object becomes a flat surface that "wraps" as it rotates.

Setup is mechanical first (mount and align the rotary), then software (configure Beam Bench's machine profile to match).

What you need

• A rotary attachment for your specific machine.
• The cylindrical object you want to engrave.
• A way to mount the rotary so the cylinder's axis is parallel to the laser's X axis (typically).

Steps

1. Install the rotary

Follow your rotary's documentation for mounting. Two common designs:

• Roller-based: two parallel rollers spin in sync; the object sits on top. Works for cylindrical objects of varying diameters.
• Chuck-based: a 3-jaw or 4-jaw chuck holds the object on one end with a tailstock on the other. More precise for known-size objects.

2. Wire it to the controller

Most rotaries replace the Y axis. Either:

• Unplug the machine's Y motor and plug in the rotary motor in its place.
• Or use a Y-axis selector switch if your machine has one.

After this change, the controller drives the rotary instead of the gantry Y.

3. Update steps/mm for the rotary

The rotary's steps-per-mm depends on its motor, gearing, and the cylinder's diameter. For roller-based rotaries:

steps/mm = (motor_steps_per_rev × microsteps × gear_ratio) / (cylinder_circumference)

Set this on the Y axis via the Console panel: $101=<value>.

Beware: this overrides your normal Y steps/mm. Restore the original when you unplug the rotary.

4. Configure the project

In Beam Bench:

• Open the active machine profile in Device Settings.
• Set the bed Y dimension to the cylinder's circumference (so 1 mm in canvas Y = 1 mm around the cylinder).
• Save.

5. Place the cylinder and align

• Set the cylinder on the rotary, axis aligned with the laser's X axis.
• Adjust focus for the cylinder's surface (top, not bed).
• Frame the design at low/no power to verify alignment.

6. Engrave

• Start a job.
• The rotary spins the cylinder around; the laser fires.
• After the job, switch back to normal Y operation by restoring $101 and replugging the original Y motor.

Verify it worked

• Framing walks around the cylinder without going past the edges.
• A small test burn produces engraving the correct size around the cylinder's circumference.

Modes worth knowing

Beam Bench may support different rotary modes (roller, chuck, with cylinder correction). Check Laser Control and the machine profile for rotary-specific options as the feature evolves.

Related

• Device Settings dialog
• Steps per millimeter explainer
• Console panel
• Focus and depth of field explainer: focus matters more on curved surfaces