Focusers???????

[rusty]

Hi All!

Thanks to all those who offered advice about my Dob Decision. I would like to say tongue-in-cheek that I am no nearer to deciding what brand to buy. Tossing a coin seems a good option at this stage.

More seriously though one or two of you made reference to a Crayford Focuser. It seems this is a desirable brand or type of focuser to have on your telescope.

So 2 more questions:

1) is Crayford a brand or type of focuser; and

2) what sets the Crayford apart from other focusers?

Again thanks in advance!

[Starkler (Geoff)]

Originally Posted by rusty

Hi All!


So 2 more questions:

1) is Crayford a brand or type of focuser; and

2) what sets the Crayford apart from other focusers?

Again thanks in advance!

A Crayford is a type describing its mechanical construction. It basically consists of a shaft bearing on a flat on one side of the focuser drawtube, whilst the other side of the drawtube rides on a number of small roller bearings.

The advantage of this type of construction is that the drawtube holds its axial alignment along the length of its travel. A rack and pinion type is much more prone to backlash and wobble as focus is adjusted.

I'm guessing the question you really want answered is, "Is a crayford worth paying the extra $ for?", and my answer is most definately !

[janoskiss (Steve H)]

The best value most functional focuser available at the moment is the GSO Crayford with 10:1 microfocuser for little over $100 from either Bintel or Andrews. Anything better will cost ~$300+ but the GSO unit is very capable and probably all you'd ever need.

[Astroman (Andrew Wall)]

I agree with the above comments, I changed the Rack and pinion focuser on my skywatcher to a crayford (JMI-DX3 worth over $300), the best thing you can do for pleasurable viewing. Most GSO scopes will accept the 10:1 focuser without modification to the tube. For only $119 its worth every cent.

[Starkler (Geoff)]

Originally Posted by Astroman

Most GSO scopes will accept the 10:1 focuser without modification to the tube. For only $119 its worth every cent.

Yep the hole pattern is the same as for the rack and pinion 2 inch gso focuser so no mods are required to fit.

In the US, these focusers are priced at $150US+
Its great to see SOME things at least cheaper here than in the US

[janoskiss (Steve H)]

All GSO gear without a Meade sticker on it and a lot of Synta gear is cheaper here than in the US. and so it should be.

[rmcpb (Rob)]

The GS crayford upgrade I did on my scope is one of the best things I have done to it. If buying a new scope now don't even consider an R&P focuser to save a few dollars.