A Linear Bearing Crayford design focuser connects to a standard Schmidt-Cassegrain thread.
Eliminates the need for focusing with the primary mirror.
In conventional Crayford focusers, the drawtube is held in place by four roller bearings. Because of the small area of contact between the focuser tube and these bearings, changes in load or telescope orientation can cause some amount of slop in the focuser drawtube. The new linear bearing focuser is built with a cutting-edge rail system made of stainless steel which provides extended, consistent, and linear contact with the focusing mechanism and the inside of the focuser body, even when the focuser is fully extended. The result is zero flexure throughout the focus travel range, even in the worst case scenario when the focuser is parallel to the ground and carrying a heavy load such as a large CCD camera. This linear bearing rail mechanism also allows the use of heavier loads
The ultra-smooth focuser adjustment knob is only topped by the 10:1 fine adjustment knob which yields superior fine-tuning that will stay in place without slippage for hours on end. For critical imaging applications, the focuser position can be locked in place via the large thumbscrew provided for this purpose on the top of the focuser. The focusing tension can be controlled by another large screw on the underside of the focuser. The drawtube features a laser-etched measurement scale for quick and repeatable focusing.
Has a load capacity up to 4.1kg.
• Minimum focuser height (without 1.25" adapter) = 118mm
• Maximum focuser height (without 1.25" adapter) = 169mm
• 2"-1.25" adapter height = 10mm
• Tube travel = 50.8mm
• Drawtube outside diameter = 59mm
• Steel rail width = 14.1mm
• Focuser weight (with 1.25" adapter) = 887gm
• Maximum outer body diameter = 82mm
• Flange thread: Standard SCT female thread (2", 24 TPI)