After a few weeks of using the 'scope I noticed the focuser was not behaving itself. It kept sticking as I turned the coarse focusing knob. At times I had to ease the travel of the focuser by hand. This state of affairs become frustrating. Research on the web revealed my experience of the DDG Crawford focuser on the GT-81 was not unique. Setting and resetting the tension by adjusting the hex screw 'B' on the base did not resolve the problem.
My WO GT-81 is a great refractor - superb optics but the focuser was letting it down and ruining my observing pleasure.
Other owners who experienced the same problem had swapped the focuser for a better make, such as FeatherTouch. However I heard William Optics had released the GTF-81 refractor which featured a rack & pinion focuser replacing the Crawford. Other WO scopes in their range now have R&P focusers.
I sent off for one from WO and have now replaced the DDG with it.
All in all I am delighted with my 'upgrade'. Has any other GT-81 owners taken this path?
My WO GT-81 is a great refractor - superb optics but the focuser was letting it down and ruining my observing pleasure.
Other owners who experienced the same problem had swapped the focuser for a better make, such as FeatherTouch. However I heard William Optics had released the GTF-81 refractor which featured a rack & pinion focuser replacing the Crawford. Other WO scopes in their range now have R&P focusers.
I sent off for one from WO and have now replaced the DDG with it.
The coarse and fine focuser is performing well so I am delighted I swapped. There are holes on the R&P focuser casing as per the DDG where the WO RDF base shoe can be attached so I have no problems using the finder.