Importance of levelling an EQ goto mount.

[Kaptain Klevtsov]

Following on from an earlier thread about the Celestron 8i being level, I wonder how the EQ goto mounts know if they're level or not? Do they therefore care?

If I understand correctly, my two goto EQs (HEQ5 and EQ6) have a design such that one axis points at the north celestial pole and a mechanism to allow the telescope to rotate about this axis. There is also a second orthogonal (at 90 degrees to t'other one) axis to allow the telescope to point anywhere in the sky.

Thats the theory, in practise I have to struggle like a fool to ensure that the polar axis is aligned, and to accomplish this I rotate the telescope to get the alignment reticule to match the real life stars. That means that the telescope is no longer accurately in its parked position when I set the goto going.

(apologies to those of you who are not familiar with the alignment of these mounts, I'll stick a bit on the end to explain).

So, what effect does the tripod not being level have? The axis is polar aligned within a hair's breadth so the only thing that can be out is the position of the RA axis shaft. I suspect that I could hang the thing from the roof upside down, provided that I could get the axis aligned, and as nobody is going to tell the software, IT won't know, so where IS the point in levelling the mount?

Captain Chaos

Bit on the end:-

The two mounts that I own (HEQ5 and EQ6) include a polar alignment 'scope built into the RA axis which has the benifit of a cartoon diagram of Ursa Major and Cassiopea. These cartoon stars are aligned with the real stars by rotating the mount axis until they are in the same orientation. Then a little circle near the centre can be placed over Polaris by adjusting the AltAz. adjustment screws. This allows for the fact that Polaris is not exactly in the right place, but off by enough to mess up astrophotography such that you can't photograph God (that was His plan anyway)

[GordonCopestake]

as long as the axis is polar aligned the tripod legs can do what they want as long as they support the weight. It's the polar alignement that is key. On unlevel ground you would need to alter your polar adjustment to match which is a pain. It's easier to level the tripod and leave the polar adjustment alone IMO

[moondog]

I would agree - I don't think that it makes a difference if the mount is level or not.

I've still ensured that my HEQ5 Got To is level and when I park the scope it goes back to the original polar alignment position.

With my usual 2 star alignment I've never had any go to problems - apart from when my watch packed in and I entered the wrong time!

MD

[GazOC]

I've never had any go to problems - apart from when my watch packed in and I entered the wrong time!

MD

Never entered the date in the wrong format? I did that when I first got my Skyscan.