12
7. care of Your HDX110
EQ-G Mount
To protect the equatorial mount, we recommend transporting
and storing it in its original shipping box or in an optional hard
case.
CAUTION: Never set the equatorial head down such
that the motor covers or encoder/gear housings bear
the weight of the mount, as this could damage those
components and the hardware inside them. If you need
to set the mount down on the ground or other flat sur-
face, always orient the mount in the “upright” position in
which only the bottom plate contacts the surface.
addendum: adusting the
Declination axis Backlash
If you believe that the declination axis (DEC) of your HDX110
EQ-G mount has unwanted backlash, or on the contrary that
the DEC worm and ring gear are binding due to being too tight-
ly meshed, follow this procedure for adjusting the gear mesh.
You will need a Philips screwdriver and a set of metric Allen
keys to perform this adjustment.
1. Rotate the saddle of the mount head to its default
position and then lock the DEC clutch lock lever as
shown in
Figure 20. Rotate the saddle back and forth
to feel how much “play” there is (
Figure 21, see Note
below). This is an indication of how tightly the worm is
meshed to the ring gear. It is normal to feel a tiny bit
of play. If you don’t feel any movement, not even the
slightest jog, the DEC gear mesh may be too tight. If you
feel a lot of play, the gears may be too loosely meshed.
NOTE: It may help to install a long dovetail plate in the
saddle, as shown in Figure 21, to give you a longer
moment arm for rotating the saddle back and forth. In our
tests it was easier to feel the amount of backlash when
we rotated the DEC axis via an installed dovetail plate.
2. Now connect the hand controller to the mount and turn
on the power. Use the hand controller to slew the saddle
several degrees left (
Figure 22). Rotate the saddle back
and forth by hand again to feel the amount of play, as you
did in Step 1. Can you feel even the slightest jog?
3. Slew a few more degrees in the same direction as in
Step 2, and again rotate the saddle back and forth to feel
the amount of DEC play.
4. Repeat the previous step, going a few degrees at a time,
until the DEC axis has completed a 360° rotation, to find
the position of the saddle where you feel the smallest
amount of play. That’s where the gap between the worm
and ring gear is smallest. Slew several degrees left and
right of this position to pinpoint the exact position where
the smallest gap of gear mesh is found. In the following
steps, you will carefully adjust the gear mesh to the
proper setting.
Figure 20:
Start with the dovetail saddle in the “default”
position, pointing straight ahead.
Figure 21:
It’s best to install a wide dovetail plate in the
saddle to test1 for DEC backlash, as it provides a longer
lever arm. With the DEC clutch lock lever tightened, grasp the
plate firmly with both hands – one hand on each end – and
jog it rotationally back and forth and feel for “play” (backlash).
Figure 22:
Slew the saddle using the hand controller a few
degrees, then jog it again as in step 2 and note the amount
of backlash. Repeat this step several times until the saddle
has rotated 360 degrees.
Wide dovetail plate
(sold separately)
Saddle
Dec clutch
lock lever
