RCF focusers come standard with a 3″ length drawtube. The following part number is for upgrading the drawtube length to 4.6″ at the time of purchase of an RCF focuser.
The Reverse Crayford Focuser (RCF) is a light-weight, low-profile focuser with a new revolutionary design - JMI′s low-cost, high-quality answer to plastic focusers. The reverse Crayford design gives zero image shift and zero backlash. (U.S. Patent No. 6,297,917)
|Name||JMI - RCF Drawtube Upgrades|
|Manufacturer||Jims Mobile, Inc. (JMI)|
|Manufacturer Part No||RCFDTUPGRADE|