eyepiece adaptors ......

I've just got my first 2 inch eyepiece, which means I now have both 2 inch
and 1 1/4 inch eyepieces. This is no problem because my focuser has 2 inch
and 1 1/4 inch adapters (Skywatcher Dob), but:

I don't like the idea of swapping adapters each time I want to change from a
2 inch to 1 1/4 inch EP, because this means undoing and re-tightening the
thumbscrews which hold the adapter in the focuser from "all the way in" to
"all the way out" and back again each time. Compare this with the
thumbscrews that hold the eyepiece to the adapter, which only have to be
turned slightly to allow an eyepiece swap in the same adapter.

This is likely to happen frequently, especially as I envisage using the 2
inch EP as a finder as well as a rich field EP.

My question is this; am I being over-fussy, or would it really make sense to
leave the 2 inch adapter in place, and buy a 2 inch to 1 1/4 inch adapter
ring to use on the 1 1/4 EPs, thereby avoiding all that undoing and
re-tightening of thumbscrews? (My concern being wear on the threads not on
my fingers !)

Thoughts appreciated ........

In article , Alan wrote:

I don't like the idea of swapping adapters each time I want to change from a
2 inch to 1 1/4 inch EP, because this means undoing and re-tightening the
thumbscrews which hold the adapter in the focuser from "all the way in" to
"all the way out" and back again each time. Compare this with the
thumbscrews that hold the eyepiece to the adapter, which only have to be
turned slightly to allow an eyepiece swap in the same adapter.

I've also got a Sky-Watcher Dob and, yes, it is a bit of a pain swapping
between 2" and 1.25" because of the eyepiece holders "dovetail" base. In
my case it just means I use my one 2" eyepiece less than I should, but I
do have a good finder so don't need to swap for that reason.

My question is this; am I being over-fussy, or would it really make sense to
leave the 2 inch adapter in place, and buy a 2 inch to 1 1/4 inch adapter
ring to use on the 1 1/4 EPs, thereby avoiding all that undoing and
re-tightening of thumbscrews? (My concern being wear on the threads not on
my fingers !)

I don't think thread wear is an issue. The luxury solution would be to
buy as many 1.25" to 2" adapters as you have 1.25" eyepieces, and semi-
permanently convert all of them to 2" fitting. If you use the "ultra low
profile" adapters from eBay seller "telescope warehouse" you could also
make all of your eyepieces parfocal by clamping the adapter in the right
place.
--
Jim Easterbrook http://astro.jim-easterbrook.me.uk/
N51.36 W0.25

snip

I don't think thread wear is an issue. The luxury solution would be to
buy as many 1.25" to 2" adapters as you have 1.25" eyepieces, and semi-
permanently convert all of them to 2" fitting. If you use the "ultra low
profile" adapters from eBay seller "telescope warehouse" you could also
make all of your eyepieces parfocal by clamping the adapter in the right
place.
--
Jim Easterbrook http://astro.jim-easterbrook.me.uk/
N51.36 W0.25

Yes parfocalisation benefits had ocurred to me too. I only have one 1 1/4
eyepiece (I'm assuming my new 30mm EP will make my 25mm came-with-scope EP
redundant) to worry about, so I am tempted. More toys ........ :-).