PrimaLuceLab ESATTO 3.5" LP Robotic Focuser

A 32mm Low-Profile Body for Demanding Astrographs

Telescopes such as many astrographs have little available back focus and need a low profile focuser. The ESATTO 3.5" LP fits 10mm of travel into a 32mm body.

The draw tube has a 90.0mm free aperture.

10kg Capacity with 0.01 Micron Step Resolution

PrimaLuceLab's special low profile design gives the ESATTO 3.5" LP 10 kg (22 lb) of payload capacity with the focusing smoothness needed for autofocusing with V-curves. It is not a Crayford design (PrimaLuceLab reserves that for the 2", 3" and 4").

The resolution is 0.01 microns per step.

Secure M98x1 Thread and Optional Adapters

The ESATTO 3.5" LP has an M98x1 female thread on the camera side; the draw tube travel moves on the telescope side.

PrimaLuceLab offers optional camera adapters with stop ring (the stop ring locks the camera at a precise angle for framing) and telescope adapters; if none fits your telescope, the user manual gives the dimensions of the telescope-side adapter so you can make your own. Examples:

• Camera side: M98 to M68 and M98 to M54 with stop ring, and M98 to M72 female.
• Telescope side: adapters for the large 3.3" SC thread (PL3600362), telescopes with SC thread, GSO/Orion/TPO Ritchey-Chretien 10" to 16", PlaneWave DeltaRho 350 and Officina Stellare Veloce RH200 and RH300.
• 3" Visual Back: For a camera with a 3" nosepiece; it has an internal brass compression ring and 3 locking screws at 120°.

USB-C, WiFi, and Full Software Integration

The USB-C port connects to a PrimaLuceLab EAGLE or any Windows computer, and the included cable fits any USB type port. For untethered use, built-in WiFi lets you control the focuser from a smartphone or tablet using the ESATTO Virtual HandPad, intended for visual use. The status LEDs are dimmable.

It comes with PrimaLuceLab's PLAY astrophotography software, which controls focus with ESATTO and rotation with ARCO and adds more advanced features on an EAGLE. An ASCOM driver (tested with ASCOM platform 7) lets third-party software control it.

Dual Temperature Sensors for Focus Stability

Focus can shift as temperature changes. An internal sensor reads the motor temperature, and a port takes the optional external probe used for focus temperature compensation.

With the probe connected, the ESATTO reports temperature with its position, and autofocus can be set to run after a temperature change.

Dedicated Port for a Seamless Rotating Focuser

The ESATTO 3.5" LP has an ARCO port. With the optional Adapter ESATTO 3,5" LP for ARCO 3" (PL3600467, 3mm optical thickness), the ARCO 3" mounts on the focuser.

The ARCO connects to the ESATTO with a single cable, without additional USB or 12V power cables. The combination is a rotating focuser 58.5mm thick with a 76.3mm free aperture (set by the ARCO 3"). ARCO lets you set the camera angle remotely and, with an alt-az mount, de-rotate the field without an equatorial wedge.

Flexible 12V/USB Power and Automatic Position Sensing

The ESATTO 3.5" LP offers flexible power options to suit your setup. It can be powered via a standard 12V DC input using the included cigarette lighter plug cable, or through USB from an EAGLE or computer; if a computer's USB ports deliver less than 0.5A the focuser may stop abruptly, and 12V must be connected as well.

Each unit leaves the factory calibrated; on the LP versions the calibration sensor detects the max in position. Calibration data is stored in the focuser's memory. Service or calibration of the 3.5" LP's internal mechanism (the registration procedure) should only be done by PrimaLuceLab.