The EV-XT 3" Crayford Focuser from JMI Telescopes is a replacement focusing system for larger Cassegrain telescopes. It is capable of supporting and lifting up to 8 pounds. This is important for astroimaging, astrophotography or when using heavy eyepieces or accessories. The Crayford-style is able to achieve highly precise focusing by its unique metal-on-metal friction system. Since it doesn't rely on tracks and gears, minute adjustments are possible to a degree that rack-and-pinion style focusers are incapable of. The focuser is designed for 10 to 16 inch Cassegrain telescopes with standard output threads.
This dual-speed focuser has textured adjustment knobs for a secure grip. With a fast-speed travel of 0.58" and fine-focus of 0.064" per knob rotation, precision adjustments are easy. The focuser base can be rotated to accomodate left and right handed users, or for easy access if the telescope orientation changes throughout the skywatch session. The focuser comes with a 2" eyepiece adapter and a 1.25" is also available.
In the Box
JMI Telescopes EV-XT 3" Crayford Focuser for Cassegrain Telescopes