Starfield Optics 2" Newtonian focuser R&P

When your Newtonian’s stock focuser starts to feel like the weak link—especially with a heavier camera train—this Starfield Optics 2" rack-and-pinion upgrade is built to add rigidity, repeatability, and fine control. The R&P drive gives a more positive, “geared” feel than many friction-based designs, and the dual-speed controls make it easy to land on tight focus without hunting.

Geared focusing designed for heavier payloads
Rack-and-pinion focusers are often chosen when you’re hanging more weight off the back of a Newtonian and want a focusing system that stays consistent through the night. 

Dual-speed focusing (coarse + 10:1 fine)
Dial in focus quickly with the main knob, then “creep” into perfect focus using the microfocus control. A drawtube lock is included for holding position once you’ve set focus.

50 mm of travel + drawtube scale
You get about 50 mm (~2") of drawtube travel and a laser-marked scale to help you return to known focus positions.

ZWO EAF mounting made straightforward
This version is listed as EAF compatible out of the box, using the standard EAF bracket, and includes a coupler (noting it’s 5 mm and may need adjustment depending on EAF generation).

Included / features

• 2" focuser body with dual-speed knobs
• 2" compression ring eyepiece holder + 2" to 1.25" adapter (with filter threads on the adapter)
• 1.25" dust plug
• Ships in a foam-fitted padded box; no manual, and mounting screws for the base plate are not included

Quick specs

• Min height (no 1.25" adapter): 79.0 mm (drawtube may extend ~32 mm below the curved plate at minimum height)
• Max height (no 1.25" adapter): 129.0 mm
• Travel: 50 mm
• Drawtube OD: 59 mm (tube cutout must exceed this)
• Weight (with 1.25" adapter): 860 g
• Max body OD: 82 mm
• Base plate curve diameter: 230mm (shims required if greater thank 230mm)
• Base plate dimensions: 90mm x 90mm
• Hole Spacing optical axis: 70mm 
• Hole Spacing perpendicular to telescope tube: 73mm
  
• Inside diameter of central hole: 78mm
• Mounting hole specification: Unthreaded inside diameter of 4.9mm