Barlow hack - 0.965" to 1.25"?

[badhex]

Hi all

Apologies if this has come up before, I can't be the only person having thought of this so I guess it must...

Anyway I have an old Charles Frank 6" 'scope with a couple of 0.965" Swift Kellner EPs and have been looking at different ways to get the best out of them. I don't want to replace the focuser so I've started looking at ways of using modern 1.25" EPs through combinations of diagonals, barlows etc. 

I know that diagonals won't work due to the focal point being too far inside the telescope, and I tried a 0.965"-1.25" adaptor but this was also too far out to focus, so this got me thinking about how to extend the focal point out. What about an adapted barlow? 0.965" barrel at one end so it can reach the focal point inside the scope, but that widens out, preferably on a gradient rather than a step to help with FOV issues, to 1.25" fit at the EP end?

Would someone with better technical/optical knowledge than me be able to confirm if this would be possible?

[coulthamst]

Have you tried a 1.25" Barlow in the .965"-1.25" reducer and a 1.25" eyepiece? Or if you have a 1.25" Barlow with a lens element that unscrews (the standard Skywatcher model bundled with many of their scopes does this) screwed directly to the nosepiece of the 1.25" eyepieces?

[badhex]

Ah, perhaps I didn't explain too well - the CF scope only takes 0.965 EPs so whatever I stick into the focuser has to be 0.965 also. I've tried a 0.965-1.25 adaptor (i.e. 0.965 barrel, 1.25 EPs) but the focuser does not screw in far enough, so I need something which fits into a 0.965 focuser far enough to hit the focal point, but to then extend that focus out (like a barlow) to the 1.25" EP holder. I'm sure this must be possible.

[badhex]

Excuse my crude drawing but this is the sort of idea I'm talking about:

[badhex]

I managed to pick up a Meade 0.965 Barlow in the interim just to give a me a few more options with what I've got, but even with that it looks like I can't get a close enough focus! The 'lip' above the chromed barrel itself stops it from fitting in all the way to the EP holder bit of the focuser

I took the RAS/0.965 adaptor out and managed to push the thing further down the tube, and although I managed to achieve focus that way, it's not ideal. I guess I'll have to have a play around.

Damn that helical focuser!