Atomstack A20 / A40 Pro Rotary Steps-Per-Rotation & Calibration Tool
Eliminate oblong circles and vertical stretching on the Atomstack A20 / A40 Pro. Use our interactive calculator below to correct your LightBurn steps-per-rotation or GRBL $101 commands, then download a millimeter-accurate calibration ruler SVG.
Rotary Steps-Per-Rotation (SPR) & GRBL $101 Calibrator
Preset: Atomstack A20 / A40 Pro (20W / 40W Diode)
Measure along the Y-axis (rotary circumference direction).
Enter this in LightBurn > Tools > Rotary Setup > Steps per rotation.
Safe continuous rotary perimeter without slipping: 224.7mm. Add weight (rice or water bottle inside cup) to prevent roller traction loss.
$101=80.000Always send this command in LightBurn Console after disconnecting the rotary attachment to restore flat Y-axis belt scaling.
Monetization Slot: Native Under-Download Banner
High-CTR placement positioned directly below the SVG export and rotary calculations. Configure your Adsterra native key in src/config/adsterra.ts.
Atomstack A20 / A40 Pro Factory Rotary & Optical Specifications
Pre-Rendered Specs| Laser Machine Model | Atomstack A20 / A40 Pro |
|---|---|
| Laser Source & Optical Power | 20W / 40W Diode (Dual/Quad Beam Diode Laser) |
| Supported Control Software | LightBurn / LaserGRBL |
| Default Rotary Mechanism | Roller Rotary |
| Default Steps / Pulses Per Rev | 2560 pulses/rotation |
| Standard Drive Roller Diameter | 16 mm |
| Optical Beam Spot Size | 0.08 mm |
| Flatbed Restore Command | $101=80.000 |
| Focal Distance & Optics | 40mm • Place fixed-focus slide block between nozzle shield and cup blank. |
Step-by-Step Rotary Setup & Test Burn Checklist for Atomstack A20 / A40 Pro
- Place Atomstack R3 or R3 Pro roller directly under laser rail.
- Connect cable to Y2 motor port or swap main Y motor connector.
- Configure LightBurn Rotary: Type Roller, Roller Dia 16mm, Steps/rev 2560.
- If tumbler slips, apply masking tape around contact bands.
- Burn calibration pattern and adjust SPR according to formula.
Worked Calibration Example for Atomstack A20 / A40 Pro
Suppose you place a standard 20oz Skinny Straight Tumbler (Diameter: 73mm, Circumference: 229.34mm) onto the Atomstack A20 / A40 Pro.
You enter a commanded test square Y-height of 20mm into LightBurn with the baseline of 2560 steps/rev.
If using GRBL steps/mm, the corrected formula produces:
Popular Tumbler Pairings for Atomstack A20 / A40 Pro
Atomstack A20 / A40 Pro Rotary Calibration FAQs
Q1: How do I configure the rotary attachment on the Atomstack A20 / A40 Pro in LightBurn?
To set up the Atomstack A20 / A40 Pro in LightBurn: 1) Go to Tools > Rotary Setup. 2) Select your rotary type (Roller). 3) Enter the factory baseline: 2560 steps/rotation (or check Y-axis $101 steps/mm). 4) Enter your roller diameter (16mm) or tumbler caliper diameter. 5) Enable the 'Rotary Enabled' toggle and test frame your object.
Q2: What is the factory default rotary steps/mm or pulses/rev for the Atomstack A20 / A40 Pro?
The Atomstack A20 / A40 Pro uses a baseline of 2560 steps per revolution for chuck rotary mode, and 80 steps/mm for flatbed Y-axis movement. Drive roller diameter on factory rollers is 16mm.
Q3: How do I reset the Atomstack A20 / A40 Pro back to flat-bed laser cutting after rotary engraving?
When disconnecting the rotary attachment, disable 'Rotary Enabled' in LightBurn. For GRBL-based controllers, send the command: $101=80.000 in the Console window to restore true 1:1 flatbed Y-axis gantry movement.
Q4: What is the best way to focus the Atomstack A20 / A40 Pro on a cylindrical tumbler?
Place fixed-focus slide block between nozzle shield and cup blank. The focal length is 40mm with an optical spot size of 0.08mm. Always focus at the apex (highest vertical point) of the cup to ensure maximum beam energy density.