The TCF-Si Focuser by Optec:
Mechanically, the Optec TCF-Si is a robust Crayford style motorized focuser with high repeatability, no play and nearly zero backlash of only 0.0013-inch. Optec's implementation is ideal for applications which require exact focus such as CCD imaging or film astrophotography. A geared stepper motor rotates the drive shaft with one step rotation of the motor equal to a 0.000086-inch movement of the drawtube. Focuser control is now accomplished via direct serial connection between the focuser and computer.
The unit adds 3.5-inches to the telescope's back focus as measured from the front to the end of the drawtube when at the mid-focus position. The total travel of the drawtube is 0.6 inches or 7000 steps. The TCF-Si focuser can easily handle cameras and instrument packages weighing up to 10 pounds. The TCF-Si can be used with a PC for automatic focus with some of the popular camera control software.
The included M90 x 1 mm Threaded Mount was designed primarily for adapting the TCF-S focuser to the TPO 6 to 8-inch RCs. This adapter fits over the M90 threads and presents the OPTEC-2400 dovetail for attachment of the TCF-Si, IFW, or any 2400 receiver.
OPT Product Number: OP-17668-19663