Paracorr question

[stanlite (Grady)]

does anyone know if the new type two paracorr will fit directly into a 2inch focuser or is it larger ??

[barx1963 (Malcolm)]

Yes, see specs on this page http://www.bintel.com.au/Astrophotog...oductview.aspx

[Allan_L (Allan)]

Not all.
It wont fit completely into a skywatcher focuser.
There is a mod to machine the lip of the focuser.
Otherwise it makes it difficult to achieve enough inward focus.

[Allan_L (Allan)]

Originally Posted by Allan_L

Not all.
It wont fit completely into a skywatcher focuser.
There is a mod to machine the lip of the focuser.
Otherwise it makes it difficult to achieve enough inward focus.

As requested, photos:
I believe the newer style SW focuser may be slightly different design,
but on mine (from Andrews) the lip to be filed down is on the bottom of the photographed ring that screws onto the end of the focus tube.

The eyepiece adapters attach to this ring.

[Allan_L (Allan)]

a copy from cloudy nights (starman1): Re Paracorr in Sw DOB:

Hopefully, your focuser is not the dreaded one with the ring on the drawtube into which fits either a 2" adapter or a 1.25" adapter.
Because if that is the case, the scope will not focus without some modification.
You see, the focuser ring has an inside diameter of 1-15/16", so a long 2" accessory (like a barlow or the Paracorr) will not pass through the ring on the focuser to sit solidly on the 2" adapter--the long accessory will bottom out on the focuser ring and require a couple inches of additional infocus beyond the roughly 3/4" the Paracorr needs anyway.
What you have to do is to remove the ring from the focuser and either machine out or simply sand out the internal diameter to slightly larger than 2" so the Paracorr will slide past the ring to seat fully on top of the 2" adapter. Otherwise, the scope will never come to focus.