SingAstro

Hi I'm looking for a 2 inch helical focuser to be placed in my dob's 2 inch rack and pinon focuser. Anyone who wants to sell one at good price?

for your info, I have tried the Orion Helical Fine Focuser, quite good, smooth, though not as smooth as the Wolanski model, but cheaper, available and good enough for its purpose.

Alternatively, try using parfocalization rings.