New binoscope project, 150mm refractor

[keith5700]

MrH, the control box now will only control IPD and diopter setting. I’ve deleted the pre-settable focus idea because of the previous mentioned problem.

I’ve had binoscopes for over 20 years, and I like to show other people the views, but I sometimes struggle to explain what they need to do to adjust the eyepieces to suit them. I’m talking about people who have probably never looked through a telescope in their lives.

The eyepiece width setting is self explanatory, but can be tricky to do when the field of view is mainly dark.

Diopter can be a bit harder to achieve. In my previous scopes, I’ve had a servo which moves one lens, or mirror, closer to the ep, and moves the other further away. The idea being that you adjust this setting until you have an identical diameter out of focus disc, from a star or planet, and then you can use main focus to get the image sharp.

But that has been hard for some people to do, so this time I’m having the right hand lens as my datum focus, and then the diopter will just alter the left hand lens, just like most normal binocs.

Yes it will have GOTO and tracking. Price wise, I’m keeping a tally, but not dared look at it yet. I’m hoping to keep under £3k, which should be ok, as I already have all the eyepieces and the tripod/stand.

And I’m aware I could have just strapped a couple of telescopes together and used some prisms and mirrors, or amici prisms, to get to the eyepieces, but I didn’t want to restrict the light quantity or the light cone in any way, so I’ve just got a lens and a big mirror in each path, so I’m happy I’ve got the most light possible from each lens. cheers.

[Mr H in Yorkshire]

GOTO and tracking, that is impressive. I think I explained that my efforts are towards an actual ride on Alt/Az binochair. Even with the integrated balancing that I have worked out the Alt and Az drives will need a lot of grunt and I don't think I can afford the gear that would be needed, at least not just yet.

I was wondering what f ratio those objectives are, the rig looks quite short so low presumably. Mine are f/5 and there is quite some CA present so I a pair of Baader minus violet filters that I expect to mount permanently in the EPs. You have used some seriously thick ali plate and other stuff so I can appreciate the materials cost, as I have just spent £300 on ali and steel. The ali (square tube and plate/sheet) is for the binoscope and the steel tube is for the binochair ALT/AZ drives and rider cage.

I am limited in tooling, I do have an ancient lathe and a bench drill, plus hand tools so I have to design for what I can achieve. My rig is thus very simple compared with yours, basically a flat platform on which are mounted the moveable objectives in their ali housings and the primary mirrors and on a pair of movable platforms (to adjust IPD), the secondary mirrors and EPs. I will post about it in a couple of weeks when I have got a bit further with the binoscope and when I know it works!

I suspect I will then have to revisit the alt/az drive arrangements. All good fun and something to do while the weather is keeping me off my bike, at the moment I do wonder if I should be making a tornado proof ark rather than ATM stuff.