On the road to the Binewtonian

[erick]

Next project - to complete that binewtonian scope I've been planning.

Thanks to helpful folks offloading eyepieces, I now have a suite of eyepieces to use. Vixen NLVs - 15mm, 25mm and 40mm. (Not sure how the 40mm will go in an f5, but I shall see.)

I also have two solid tube 8" f5 newtonians. I have one helical focusser for testing.

So next step is to come up with the right arrangement at the eyepieces - diagonal in a simple focusser (which will primarily serve to get the IPD right), with a helical focusser for actual focussing. I might be able to restrict myself to 1.25" only.

Then the task of designing and constructing a frame to allow alignment of the two tubes and movement of both in the Alt/Azi directions.

[niko]

good luck Eric.

I'm sure you'll produce a beautiful scope with your normal level of superb and thoughtful craftsmanship.

It does however sound like you have a lot of time on your hands and could therefore manage a 20hr round trip to Vic in late March!

niko

[David Fitz-Henr]

Should be a fascinating project. I've always liked the idea of binocular telescopes. Don't forget - lots of pics and detail please!

[Satchmo]

Erik- If you have rotating tops or tubes you don't need a helical focus each time you change IPD. If you allready have 2 solid tubes then your binoscope is 80% finished. Just swap out the focussers for low profile GSo's and fit 1.25" star diagonals . You may have to more the primary forward a little.

Have you seen Dave's 8"" F6 bino ?
http://www.binoscope.co.nz/babybino.htm

[erick]

I'm not planning on rotating the tubes, Mark. That is mechanically hard for me to build and I'm sure I'd end up with play in the tubes.

Finally got some time today to play with one of the 8" f5 tubes.

Yes, confirmed that I need a low profile focusser on each tube to counter the inclusion of a 1.25" star diagonal. I still plan to use the focusser solely to adjust the IPD. But I don't need fancy 10:1 focus - just a 1:1 will do, but I suspect they all are sold as 10:1. I'll have to test my luck in the classifieds.

I need to get my focus with helical focussers - looking at the 1.25" Borgs. Non-rotating would be nicest, but the premium compared to the rotating version is significant. I'll just need to put on the eyepiece heaters after I am close to focus.