Lumicon - Low-Profile 1.25in Focuser for Newtonian on 3.5in Base with 2.75 " hole pattern

The Low Profile 1.25" Focuser for Newtonian, 3.5" Base, is a high-precision, pin-and-groove type helical focuser. The 3.5" base provides for replacing larger focusers with a center-to-center hole-spacing of 2.75". The draw-tube does not rotate.

Accessories that take up back-focus, such Lumicon's popular 1.25" Multiple Filter Selector, can be used with ease and convenience. The high-precision, smooth focusing brings out the very best in your telescope's optics. The low-profile design quickly and easily converts your standard Newtonian to a camera-ready telescope. The U-groove base aligns and sits flush on any telescope tube with a radius of 4.5" or larger.

Specifications:

Focuser Minimum Height Above Tube*
1.75" (for 4.5" radius tube)
2" (for flat-base mounting)
Turns ratio: 2 per inch
Travel: 1"
Resolution/Backlash: < 0.0005"
Image shift: Negligible
Reverse action: Negligible
"Stiction:" Negligible

Footprint: 3.5" square
Mounting hole pattern: Square; 2.75" center-to-center
Min/Max focuser hole diameter: 1.5"/3.3"
Operating range: to 20°F/- 7° C
Maximum recommended load: 3 lb.
Mounting Hardware: 8-32, included

*Precise minimum depends on radius of tube.

Note: Visual use of the Low Profile Focuser requires either the Lumicon 1.25" Multiple Filter Selector, LF5010, or a 1.25" extension tube, such as the Lumicon LA1020.