Astronomy Plus 2" Dual-Speed Rack & Bearing Focuser Newtonians
Precision focusing is the foundation of a great observing experience, and this 2-inch dual-speed focuser was engineered from the ground up to deliver exactly that. Developed after years of dedicated research, it combines a patented bearing-and-rack system that sets it apart from conventional focusers.
A unique approach to stability Eight evenly distributed bearings share the load in every direction, eliminating play and flex while supporting heavy eyepieces and camera setups with ease. Unlike traditional designs where the focuser tube bears the mechanical load, the rack here handles transmission only — meaning force applied during focusing never introduces drift or shifts your optical axis. The result is exceptional light-path stability, surpassing that of premium focusers in its class.
Smooth, confident control The dual-speed fine adjustment mechanism delivers a silky, feather-light feel at the fingertips. Whether you're doing a rough focus pass or dialing in critical sharpness for high-magnification planetary work or astrophotography, each movement is precise and predictable. The fine-adjustment gear is also compatible with synchronous belt drives for motorized setups.
Payload Capacity: Supports heavy accessories such as cameras, filter wheels, coma correctors, and imaging trains up to approximately 5.2 kg.
Specifications at a glance
- Barrel size: 2 inches
- Clear height: 40 mm
- Available focusing stroke: 35 mm or 60 mm
- Body weight: approx. 600 g
- Bearing preload: fully adjustable for zero-clearance fit
- Dual-speed fine adjustment
- Payload: 5.2 kg
Whether you're a visual observer demanding a rock-solid platform or an imager chasing razor-sharp stars, this focuser offers the build quality and tactile refinement to match your ambitions.
Choosing the right adapter
The focuser is compatible with all Sky-Watcher Quattro Imaging Newtonian Telescopes.
However, the Sky-Watcher Quattro Imaging Newtonian Telescopes come with two different adapters, as shown in the image below:
This is a round adapter with protruding parts. This adapter is compatible with Sky-Watcher Dobsonian Telescope.
This is a round adapter, and it belongs to a different model. This adapter is compatible with Sky-Watcher Quattro 150P/200P/250P/300P Newtonian Telescope
The choice depends on the user's telescope configuration.
Please see the image below:
Choosing Between the 35mm and 60mm Travel Versions
This focuser is available in both a compact 35mm travel version and a longer 60mm travel version to better match different observing and imaging needs.
35mm Travel Version
The 35mm version is ideal for astrophotography setups where rigidity, compactness, and reduced flexure are important.
Its shorter travel helps keep the imaging train more stable while reducing overall weight and profile. This version is generally recommended for users with a well-optimized imaging setup and known backfocus requirements.
Recommended for:
- Astrophotography
- Compact imaging setups
- Users wanting maximum rigidity
- Permanent or optimized setups
60mm Travel Version
The 60mm version offers additional focus travel, making it more versatile for visual observing and mixed-use setups.
It is especially useful when using multiple accessories, diagonals, reducers, or eyepieces requiring larger focus adjustments.
Recommended for:
- Visual observing
- Mixed visual and imaging use
- Users with multiple accessories
- Situations requiring greater focus flexibility
If you are unsure which version to choose, the 60mm version is typically the safest and most versatile option, while experienced astrophotographers often prefer the more compact 35mm version.
Compatibility
This 2" dual-speed R&P focuser is designed primarily for Sky-Watcher Newtonian telescopes using the standard Synta-style round focuser base. It is especially well suited for imaging Newtonians requiring a low-profile focuser.
Common Compatible Telescopes
Sky-Watcher Quattro Series
- Quattro 150P
- Quattro 200P
- Quattro 250P
- Quattro 300P
Most Sky-Watcher Dobsonian telescopes
Other Possible Compatible Models
- Some Orion Newtonians
- Some GSO / Kepler / rebranded Newtonians (may require modifications or adapter plates)
Important Compatibility Notes
Compatibility depends on:
- Tube curvature
- Focuser base diameter
- Existing mounting hole pattern
- Required focuser height / backfocus
Some older Sky-Watcher models may require modifications or adapter plates for installation.
If you are unsure about compatibility, feel free to contact us with your telescope model ,photos of your current focuser and dimensions for assistance.
Technical Specifications
| Barrel diameter |
2 inches (50.8 mm) |
| Clear height |
40 mm |
| Focusing stroke |
35 mm or 60 mm |
| Body weight |
≈ 600 g |
| Drive system |
Rack & Pignon / bearing (pattented) |
| Number of bearings |
8 (evenly distributed) |
| Bearing preload |
Fully adjustable / zero clearance |
| Speed adjustment |
Dual-speed (coarse + fine) |
| Motorisation compatibility |
Yes, ZWO and EAF synchronous belt drive ready |
| Rack type |
Toothed / transmission only (load-independent) |
| Intended use |
Visual observation & astrophotography |
| Compatibility (with adapter) |
Stand |
Diagram
In the Box
- 2" Dual-Speed Rack & Bearing Focuser, selected travel length : 35mm or 60 mm
- Newtonian Adapter
Warranty
Astronomy Plus limited Warranty
