ETX TECHNICAL TIPS Last updated: 12 March 2003

ETX-60AT Tuneup

Sent:	Sunday, March 9, 2003 12:19:06
From:	benito.loyola@cox.net (benito.loyola)
Here is some information that I could not find anywhere about getting
into the ETX-60's base.  If you deem it valuable information your
audience you are welcome to post it.

I was one that purchased the $90 ETX-60 from Costco.  Soon thereafter I
was enjoying a wonderful little Go-To, but I soon realized that it had
all the same problems that the other ETXs had:

1. Difficult clutching on both axis.

2. Go-To would continue to run past final position

3. Lots of movement in both axis.

I found the wonderful "Weasner's Meade ETX tech Tips" site and wanted to
do the Tune-up procedures that are listed but I could not find
information about getting into the ETX-60.  The ETX-60 is unique in that
it does not have a removable nut in the base.  But I persisted and I am
glad I did.  Here is how I did it.

1. Removed lower cover plate at base.  It exposes a 3-pronged pressure
plate and clutch mechanism.

2. Removed chrome plated Azimuth clutch locking lever with a small Allen
wrench.

3. Loosen the bolt.  This allows the clutch mechanism in the base to
come off. You will have a locking ring; it has the threads, a washer, a
bearing ring, and the 3-prong pressure plate.  Removing these items
exposes a white plastic nut looking item.  This is where you have to
have faith.  The nut is not a nut but a plastic bushing that was epoxied
into the base metal shaft by Meade.  Thus the only way to get it off it
to shear it off.

4.  Find a socket that snugly fits the plastic nut.  Press it down
firmly onto the head of the nut, you don't want it to slip.  Insert the
socket wrench and give it a twist, either way is fine it does not
matter, it does not have threads. It will take quite a bit of force but
it will shear right off.

5. One the nut is off then the bottom base cover will slide off the base
shaft.  From here on out you can follow the instructions that are listed
for the other ETXs. There are some differences between the scopes but
just modify your procedures accordingly.

What you will find is:

   1. Loose plastic pieces from the manufacturing and assembly process
   everywhere.

   2. Way too much grease on everything in sight.  My scope had a pile
   of it building up around the optical encoder, which caused my scope
   to operate erratically.

I used Mineral Spirits to clean every piece and used white Lithium
grease sparingly for reassembly per the ETX tune-up instructions.

6.  The one modification that you will need to make is to drill two
holes on the metal base shaft and drill two holes that align at the base
of the plastic nut you sheared off.  First sand down the rough plastic
left behind from the shearing for both the bottom of the plastic nut and
the top of the base shaft.

7.  I used two pieces of coat hanger metal cut 3/4 inch long each. 
Using a drill bit the same size as the diameter of the coat hanger
metal, drill two holes opposite each other down into the plastic " deep
at the top of the metal base shaft right up to against the shaft's metal
edge.

8.  Tap in the two metal rods into the holes leaving 1/4" exposed. Place
the plastic nut over the top of the exposed metal rods and press down
while aligning the plastic hole with the base shaft hole.  You can use
the same bolt to align the pieces up that was part of the scope.

9.  Once the plastic nut has been marked underneath carefully drill two
holes about 1/4" into the nut.

10. Once your ready for reassembly the two metal rods will keep the nut
from spinning and allow the clutch mechanism to engage.  I thought about
gluing the rods in place but I found it works great without it and if
you want to get back into the base you will need to be able to remove
that white plastic nut again.

The ETX-60 tune-up will require some mechanical tools and skill but I
found it a reasonably easy way to do the tune-up and get it back working
better than ever before.

I wish you the best, and thank you for a great site!

Sincerely,

Benito Loyola

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