From: "Jerry Bowen" (4codeman@live.com)
Date: January 5, 2022 at 15:33:12 MST

Some recent repairs on an ETX-125EC I did for a friend.  Images
attached.

It appears that the Dec worm gear’s assembly plastic stud stands broke. 
I do not know how many times I have taken apart plastic items, that had
screws screwed into these plastic studs and those studs were either
broken apart or split.  I had the same problem a few months ago in my
laptop’s screen plastic housing.  I used JB Weld, and not the JB Weld
for plastic, to coat around the plastic stud.  However, you may have to
use plastic glue in the split along with something to clamp the stud
tightly together prior to using JB Weld.  You do not want the screw to
go in and be loose if you do not clamp the vertical post sides
together.  I have tried the Plastic JB Weld on plastic and it is not as
good as the JB Weld that can be used for metal.  Sometimes the stud is
broken so bad you have to figure out another solution.  And that is what
I did on this repair.

I assume that the break happened due to over tightening of the Dec
clutch (vertical lock) or possibly leaving the accessory #932 Erecting
Prism in place when a slew was done to be almost vertically straight
up.  That accessory will hit the base if trying to view an item almost
straight up.

I looked over the RA motor and its supporting plastic mounting brackets
also.  They were not damaged, but from other YouTube videos I have seen
on this model ETX, the RA motor’s plastic support items usually break
also.  I did not see any breaks and I was not about to disassembly that
item unless I did see a break.  I did run the RA motor to see how things
were meshing and all seemed well.  I did experience some non-movement of
the worm gear when I turned the RA motor gears.  The area of the multi
number of gears, I will call the reduction gears, move more before
actually moving the worm gear.  I noticed that when pressing the right
of left buttons on the hand controller, that there was some elapse of
time before the RA would move.  I was hoping to remove this slop, but I
did not see any way to adjust those gears.  The worm gear was already
secure on the base RA main gear.  I have adjusted the slop out of gears
before but never up in the area of that multitude of reduction
gears.

I hope this fix holds up.  I will advise my friend not to over tighten
the Dec clutch and be sure to remove the accessory on the back if
wanting to view something almost straight up.


I also removed some grease from the sides of the Dec gear contacts to
surfaces.  Grease should not be on those flat surfaces.  I did put a
small amount of grease on the gear’s teeth area but not enough to work
back down between the contact flat surfaces.  Friction is used to hold
the position of the RA and if grease is on those flat surfaces, then you
have to apply more tightening pressure which could break those plastic
studs that have screws in them.

Attachments:


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