Custom 4" FLI PDF focuser made exclusively for Dream.

This electronic focuser offers a theoretical step size of 1.3 microns and is therefore an excellent choice for faster optical systems with very shallow depths of field. It is the only focuser Dream has tested that offers the repeatability that we require. It has also been used around the world by amateurs and professionals alike.

 

You can distinguish this 4" Dream PDF electronic focuser from the standard FLI PDF model in many ways. One is the text below the FLI logo. Another is the all silver appearance and larger diameter drive screws. Dream requested this larger diameter and stainless steel drive screw because of the imaging train loads expected with the custom 4" coma corrector.

 

Click on the small image to see the push/pull locations on the 4" Dream PDF.

This eliminates the need for a custom adaptor on the OTA side of the focuser. It also allows a much wider connection to the OTA.

You can (faintly) see the three large 3/8"-24 tapped holes around the periphery of the unit, which is 8" OD.
 

The wider connection means a more stable platform and finer adjustments for tip/tilt. 
 

Additional metal was left in the motor side's plate, next to the 3/8"-24 tapped holes. This additional metal is used for the push screw to drive against, which would have caused flexure in the standard PDF unit. 
 

 

 

 
 

pricing, availability and specifications subject to change without notice