Fine alt/az settings for EQ-2

I suggest you optimize your EQ-2 mount (old model) with fine altitude and azimuth adjustments. You can also install a round spirit level.

A - Altitude axis in which the mounting block is housed. The D-bolt support plane is at 45°. A metal plate is required to protect the plastic. I've chosen to stick a 2-cent coin to it with double-sided tape. The aluminum might be a little too "soft".

B - M5x60 threaded rod with two nuts and two washers. It locks the mount and its possible rotation on the C-axis. My right ascension motor will be attached to it.

C - The two screws that held the mount on its altitude axis are shown here on either side.

D - Altitude axis adjustment knob with M8x80 hex head bolt, the end of which has been rounded off.

E - The small elevation pointer is fitted into the two small holes in part A with its two small screws. The graduation has been cut and glued back together with a 90° rotation.

F - The altitude axis. A 12mm-diameter aluminum tube is inserted, into which an M10x70 threaded rod is slid. Two M10 nuts on either side hold it all together. These must be tightened, but without blocking the axle.

G - Two-part alt/az parts. They are connected and tightened by two M5x100 threaded rods with bolts and washers. One M8 nut is housed in the first part and two M5 nuts in the second. You'll need two M5 knobs with 30mm long bolts to adjust the azimuth axis (no STL files for them as I got them elsewhere).

H - Small two-part piece for gluing a round spirit level up to 18mm in diameter. You'll need to drill a hole to secure it with a small M4x10 bolt and its nut.

I - Azimuth adjustment stop. This is fixed with an M8x20 bolt in the old thread used to lock the azimuth axis.

J - Azimuth axis clamping handle, which now locks from below. The bolt is an M6x20 with hexagonal head and kodak (whitworth) thread. Don't forget to loosen it a little when adjusting the azimuth.

The mount is easy to use up to 55° latitude. Beyond 60°, there's a risk that the tube/counterweight balance point will overshoot the azimuth axis, tipping the mount backwards. So, for very high latitudes (which are even rarer), you'll need to lock the altitude axis by tightening the M10 nuts. In the STL files, you'll find handles for tightening the altitude axis, to make the operation easier.

All parts subject to mechanical stress were printed at a 75% fill rate with 4-line shells. Other parts such as knobs or handles can be printed with far fewer requirements.

I used PET-G, which is UV-resistant because I do sun observations. The color white is also appropriate for this kind of observation.