The open loop belt drive attaches to the coarse focus knob via the thumbscrews as shown in the photos below. The fine focus knob pulley is attached to the fine focus knob as shown via the setscrews located on the fine focus knob pulley. The belt is stretched between the two pulleys as shown and once in place the cover is installed. The drive is connected to the controller via the connector on the rear of the drive.

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