Balancing the Mount
The next step in the setup of your equatorial mount is to balance it in the two dimensions corresponding to the two axes of movement.
Note: This article used to recommend doing the two steps below in the other order, but reader Steven Yokey kindly referred me to a good article explaining why it is better to do the Declination axis first. I’ve reversed the order, so the steps below now reflect the advice in that other article. Thanks Steven.
Balancing your mount is an important step (often overlooked by beginners). A balanced scope will move more smoothly and will tend to stay where it is put until you move it, while an unbalanced scope will have jerky motions, be unstable, and tend to drift. Worse, an unbalanced scope puts more load on the gearing in the slow-motion controls, and can cause the small motors in a motorized scope to overload and burn out.
Balance in Declination
In some rare cases – usually involving a light telescope connected to a heavy camera – you may not be able to slide the OTA or dovetail far enough to reach balance. In such cases you may need to buy or build some kind of counterweight that fits onto the OTA or dovetail (usually the dovetail, near the front) to help achieve balance.
In the above photos no such “declination counterweight” is needed.In the photo to the right, as an example, a home-made counterweight (a hunk of brass) is bolted on to the underside of a lightweight OTA, near the front, to offset the weight of a heavy camera on the back.
Balance in Right Ascension
Continue adjusting the counterweight until the scope will balance evenly on this axis.
Small mounts will come with a small counterweight suitable for a small telescope (or with the supplied telescope if purchased as a kit). If you change to a larger telescope, or add a camera or heavy accessories, you will almost certainly need another or a larger counterweight.
Congratulations, you have now balanced your telescope in both dimensions of motion. You can loosen the clutches and return the scope to its normal rest position. When you later move the scope to find or track objects, it will be well balanced and smooth and, if you have electric drive motors, you will have minimized the work they have to do.
The next step is to adjust the Finder.