Scope balancing with asymmetric OTA

[AlistairHowie]

Back to basics here, I'm afraid, a question about how to balance a refractor on a AZ-EQ6GT.

Typical advice seems to be to rotate the axes to put the mount and scope in a horizontal T-position when viewed from above, and then balance each axis separately. The issue I have is that when it's balanced in that position, it's not balanced when the OTA is rotated to near vertical, because of the asymmetry of my OTA, which has a guide scope and camera off to one side. Rotating the OTA in the tube rings isn't an option because the focuser will contact the mounting plate ... so what to do?

Should I just put the scope in a typical viewing position e.g. 60 degrees upwards, and then do my balancing that way, rather than bothering to balance horizontally?

At the end of the day, the mount is hardly stressed - it's got less than 8kg weight on it when set-up for imaging, and the specs suggest its capacity is 18kg for imaging and 25kg for visual. As long as I balance East heavy when imaging, is it going to matter much that that things are not perfect?

[andrew s]

You are correct about the balancing you need it to balance in 3 planes. I add strips of roofing lead as counter balance on my home-made telescope. You will need to rebalance in the other two planes afterwards though. Regards Andrew

[Merlin66]

Set the dec axis horizontal, the OTA vertical and add weights to the OTA to get it to balance ie sit exactly vertically.

Then do the normal balancing in Dec and RA.....

Simples!

[AlistairHowie]

Thanks for the advice Andrew/Merlin.

Is there a way to get a satisfactory set-up that doesn't have me adding extra weights to the OTA? I appreciate that without them the system won't be fully balanced in all orientations, but is it "permissable" to balance the DEC axis when the scope is pointing roughly where it will actually be used, and to balance RA in the horizontal?

What is the "cost" of balancing the scope that way for imaging purposes (actually making it East heavy in the above process)? If I'm synching on a local star for imaging, goto's potentially being off aren't going to bother me. And I'm way below weight capacity on the mount, so as long as I'm balanced when imaging, wear and tear shouldn't be an issue, should it?

[Merlin66]

IMHO it's much easier to do the job correctly - done once, play forever.

[AlistairHowie]

Understood. Can you direct me to a web site selling the sort of weights that I can use to balance my refractor, which is currently mounted in a set of 95mm tube rings? Many thanks.

[cosmojaydee]

Call into a Kwik Fit centre ( tyre place) they have a self adhesive stick on weight for alloy wheels, maybe they will sell you a few strips

[AlistairHowie]

Ahhh ... now there's a good idea, thank you. Kind of goes against the grain spoiling my lovely Baby Q in this way. I know I should do it, but maybe I'll just try DEC balancing at the angle I'll be using the scope at, and see how things go. As long as I'm East heavy, I can't help but think this maybe isn't such a big deal with my lightweight set-up. But perhaps that's just wishful thinking on my part.