Alignment of Dual Scopes - Need Ideas

Have been thinking for years about the alignment of dual scopes. Seems like the "Optec Libra Alt Az adjustment" is nice but big $$$. Ken D's adjustable dual saddle are only for the vixen-type plates. I always thought that someone could figure something out with just a losmandy plate, quality rings (ones with a wide base), and four "push-pull" sets at the corners. This would be for the do-it yourselfers who dont want to spend $$$ and can tap some holes in the plates. Has anyone attempted or thought this thru? See my BAD sketch.

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Works OK for up/down, but what about left/right? Slotted holes for the inner "pull" screws maybe? Either one would require a long dovetail rail and wide ring spacing to get the rings beyond the jaw for field alignment relative to the other scope. Also, you could probably get by with one "pull" screw in a crossways slot at the center and the two "push" screws outboard. Fine adjustments may be hard though as I've found that screws in slotted holes tend to creep a tiny bit as they're tightened.

Jim

Shims on the dovetail? The pointing models like TPoint will accommodate small orthogonality errors, but only for one tube.

Sorry---but I cannot figure out what you are trying to do here?

Just mount two tubes on the same mount? I've seen that done many ways, very simply with two sets of rings loaded on dual dovetail plates.

Isn't that what you want?

Alex

The four screw push-pull will work just fine as you have it drawn, as long as the scopes are fairly close to start with.
That's almost exactly the way I've done it in the past. After getting the scopes aligned that way I measured and then shimmed the rings to keep it aligned. Shims available at Mcmaster-carr, or at Stock Drive Products, all kinds of them!! If you just leave the rings resting on the screws, you are also using the OTA as a structural member to prevent the rings from twisting. I don't think that would prove to be a good long term idea.