2" extension tube?

[Bart]

Hi all

I have a problem with some 2" EPs. I essentially have 3 2" EPs. One achieves focus without trouble. The other two don't. Without the extension, one of them is too near, but when I insert a 35mm extension tube, its too far out. Is there a shorter 2" extension tube? Or a saw an attachable threaded ring to permanently extend individual EPs. Bit annoying, currently fixing the EP forcibly using the thumbscrew and compression ring. Any advice? Much appreciated.

Barry

[Dude_with_the_tube]

i had the same problem with my scope and standard focuser and had to use the extension tube on all EP as i was unable to reach focus on ANY of them and then i was able to reach the focus by just a close margin.Eventually i got fed up with it and i bought Moonlite CR2 and now I dont need any extensions and Ep`s fit straight into focuser. Expensive upgrade but well worth it.

As for your case,2 options:you can get the extension tube machined down and make it smaller to be able to reach inward focus if that is your problem.there is a video on youtube about not reaching focus.But another option is following: get one of these:http://www.teleskop-express.de/shop/product_info.php/info/p3702_Base-for-Newtonian-focusers-for-tubes-D--260mm-and-larger.html to raise your focuser off the base.by using the raiser you will eliminate the need of using the 2" extension.they do come in different thickness's i think also FLO does them.Moonlite uses the same thing and works perfectly. Hope that helps you mate.

Clear skies.

[Moonshane]

just buy a Baader fine tuning ring (28mm or 14mm - probably the former). this will allow you to pull the eyepiece out a bit and remain secure.

[Moonshane]

http://www.firstlightoptics.com/baader-planetarium/baader-hyperion-finetuning-ring.html

[John]

just buy a Baader fine tuning ring (28mm or 14mm - probably the former). this will allow you to pull the eyepiece out a bit and remain secure.

Yep - thats the solution I use with my Ethos eyepieces. The 28mm ring gets them to the right place for all my scopes.

[Bart]

As always gents, many thanks.

Barry