Lunt 1.25″ Mini Helical Focuser

Lunt 1.25″ Mini Helical Focuser

Helical Focuser

The Lunt Mini Helical Focuser is a non-rotating focusing system that provides a T2 (male) to T2 (female) threaded connection. It offers 10 mm of precision travel, ensuring smooth and accurate focusing. The focuser includes a brass compression ring to protect eyepieces and a locking collar for stability. Designed with a T2 thread, it is ideal for achieving precise focus when using cameras or eyepieces.

1.25" Rack & Pinion Focuser

In telescopic applications, the focusing mechanism plays a vital role in connecting the main optical system with observation equipment. While helical focusers have traditionally been used in entry-level and solar telescopes, they present mechanical drawbacks that can reduce optical performance. Common issues include backlash, limited load capacity, mechanical instability under temperature changes, and insufficient precision for high-magnification observations.

Transitioning to a rack and pinion focusing system resolves these issues through improved mechanical engineering and CNC precision manufacturing.

Specifications:

• Focuser Size: 1.25"
• Drive Mechanism: Rack and Pinion
• Drawtube Travel: 0.5"
• Rotatable: Yes
• Compression Ring: Yes
• Positioning Accuracy: ±0.002 inches (±0.051 mm)
• Load Capacity: 6–8 lbs (2.7–3.6 kg)
• Backlash: <0.001 inches (when properly adjusted)
• Materials: CNC-machined Aluminum and Brass

2" Rack & Pinion Focuser

The Lunt Solar Systems 2" Rack & Pinion Focuser is a dual-speed precision-engineered focuser built for smooth, accurate, and repeatable control during visual observation or high-resolution solar imaging. It features a 2" drawtube with approximately 55–60 mm of travel and a 10:1 fine-focus reduction ratio, allowing effortless micro-adjustments for perfect image sharpness, even at high magnifications. Constructed from durable materials with tight tolerances, it ensures exceptional stability and a secure hold under accessory loads of up to 3 kg (6.5 lbs).

This focuser is standard on most Lunt Modular Telescopes (MT Series), including the 60MT, 80MT, and 100MT models. The 2" compression ring fits both 2" and 1.25" accessories (with adapter included) and mounts directly to the rear adapter plate via M68 or M90 threads, depending on the telescope’s aperture. For automation enthusiasts, the Lunt 2" Rack & Pinion is fully compatible with ZWO EAF and Optec FocusLynx/ThirdLynx motorized focusing systems, offering flexibility and precision for both observers and astrophotographers.

Specifications and Details:

• Type: Dual-speed precision Rack & Pinion focuser

• Size: 2" drawtube (standard telescope accessory size)

• Reduction: 10:1 fine-focus control for imaging and visual work

• Travel: 55–60 mm total drawtube travel (varies by model/telescope)

• Mounting Thread: M68 or M90 thread interface (depends on aperture class)

• Compatibility: Standard on Lunt MT telescopes (60MT, 80MT, 100MT)

• Eyepiece Side: 2" compression ring with 1.25" adapter included

• Load Capacity: 2.5–3.0 kg (5–6.5 lbs), suitable for large CCD/CMOS cameras and filter wheels

• Optional Motor Focusers: Works with ZWO EAF and Optec FocusLynx/ThirdLynx systems (compatibility links provided by Lunt)