Crayford focuser overall length

[Merlin66]

Guys,
Need a bit of help.....
For the SHG prototype I used a 2" SCT Crayford focuser (this is used with 2" fittings - no 2" to 1.25" adaptor...)
The overall length (minimum) from the mounting face to the end of the drawtube is 75mm.
Due to a screw up on my part(!!???) I can't get a good clean focus....I need about 5-10mm further inward movement.
There are no optics I can move to compensate, so a shorter 2" 10:1 geared focuser which either fits a flat base or a SCT thread is what I need.
My question: Has the Newtonian Crayford focuser a shorter closed length say around 65mm???
http://www.bintel.com.au/Accessories/ATM-Supplies/Bintel-Crayford-Focuser-10-1--2----303mm-Tube-/62/productview.aspx
Anyone know if this is available with a flat mounting base plate?
Any other ideas....???

[Merlin66]

Hmmmm
No comments/ alternatives????

[SteveInNZ]

The JMI EV SCT focuser is 60mm from mounting face to the end of the drawtube.

Steve.

[Merlin66]

Thanks for the info Steve.
I'll follow it up.

[SteveInNZ]

I'd better hang on to it until I've seen your book then. :)

Steve.

[Merlin66]

Steve,
It was a pilot error...measure once, measure twice - and still get it wrong!!

[MattT]

Hi Ken,
The GSO focusers I have Refractor Crayford, Linear Bearing and SCT + Newt all have the same body length 75mm to the end of the 2" bit.

Other ideas are expensive....FT will work.

Andrews sell a Long Pern refractor focuser that might work, but I don't know the actual body length.

Matt

[sharptrack2]

Hi Ken,

Being a little self serving here and I'm not sure I even know what I'm talking about... but the Moonlight focuser, without the mounting flange is about 47mm, with a tube travel of about 25mm.

I have one that is DC servo driven and hasn't found a home yet. Would you like a pic or two to look at?

[Merlin66]

Kevin,
Thanks for the offer, but I may have found a solution.