ESATTO 4'' Focuser with ARCO 3'' Rotator

PrimaLuceLab ESATTO 4″ Focuser with ARCO 3″ Rotator — an integrated bundle designed for demanding astrophotography setups with heavy imaging trains and large optical systems.

What’s included

• The PrimaLuceLab ESATTO 4″ Robotic Focuser, a high-capacity motorised focuser.

• The PrimaLuceLab Adapter ESATTO 4″ for ARCO 3″ (specific adapter needed to pair the focuser with the rotator).

• The PrimaLuceLab ARCO 3″ Camera Rotator/Field De‑rotator, a precision camera rotator/field–de-rotator.
  (Note: Some bundles may list the adapter separately, but the full bundle reference is PLLEST4ARCO3 per the manufacturer.) 

Key Features & Benefits

ESATTO 4″ Focuser:

• Large Clear Aperture: ~102.2 mm free aperture, suitable for large format sensors and wider field optics. 

• Draw-tube Travel: 35 mm of travel to allow for heavy imaging trains, filter wheels etc. 

• Payload Capacity: Up to ~10 kg imaging train load, which is substantial for serious astrophotography rigs. 

• Fine Resolution: ~0.04 micron per motor step focusing resolution — excellent for critical focus work. 

• Build & Connectivity: Crayford-style focuser with 40 ball bearings for smooth, low-flex movement; USB-C control, WiFi, ASCOM drivers, dedicated “ARCO port” for rotator integration. 

ARCO 3″ Rotator / Field De-rotator:

• Free Aperture: ~76.3 mm (for the 3″ version) — sufficient for large sensors/optical trains. 

• Thickness / Low Profile: Only ~23mm thick (body) — important for maintaining back-focus. 

• Precision Rotation: 1 arc-second per step resolution — enables precise camera framing or field de-rotation on alt-az mounts. 

• Seamless Integration: Designed to connect directly to the ESATTO focuser via the dedicated port and adapter—minimising extra cables and simplifying mechanical stack.