astro-babys guide to stripping and rebuilding the HEQ5 mount
2 - Synta HEQ5 - Lubrication & Re-Assembling the Declination (DEC) Axis


This procedure will guide you in re-assembling the HEQ5 Declination axis and follows on from the stripping down and cleaning guide HERE.

NOTE 1: Very little of the mount assembly requires brute force on tightning down components. They need to be firm but not so tight the threads pop.
Generally a light touch is required rather than brute force. Remember this is a precision piece of engineering and many of the fittings are aluminium so threads
can be easily stripped and ruined.


NOTE 2: When this guide was originally written the accepted wisdom was that white lithium grease was an overall good lubricant. However it would appear that
standard white lithium grease may cause problems under some extremes of damp/temperature. All of the mounts I have rebuilt have been done with white
lithium that is stable and often mixed with a syntehtic like Teflon or PTFE. It is best to consult the manufacturer on the quality of the product.
 
Stage 4 - Re-assembling the Worm Carrier
Replacing the worm in the carrier Replacing the float adjuster in the worm carrier The assmebled worm carrier
Lubricate the small roller bearings and replace them
on the worm, then replace the worm in its carrier.
Note: the worm has a longer spindle one end than
the other.The longer end goes to the motor gear.
Replace the float adjuster and tighten down. The
adjuster should be just tight enough to stop the
worm moving from left to right in the carrier but not
over tightened. If its too loose there will be 'play'
in the mount, if too tight the mount may 'bind'.
Here is the assembled worm carrier. Its been
cleaned and loose flaky paint removed.
You can see the worm now has a thin coat of lithium
grease.
Note: The motor gear can be reattached now or
left until later.The motor gear must have one of its
set screws on the flat portion of the worm spindle.
     
Stage 5 - Re-assembling the Declination Axis
Replacing the DEC housing main bearing Relacing the brass worm gear on the declination barrel Replacing the round nut on the Dec barrel
Replace the bearing in the main housing. Apply a
thin layer of lithium grease to its surface.
Reassemble the brass worm gear with its bearings
(you may need to tap these in with a nylon mallet)
and replace the assembly onto the Declination
barrel and shaft. Apply a thing layer of lithium grease
to the gear and all bearing faces.
You can also see in this pic the main housing
bearing has had lithium grease applied to its
bearing face.
Replace the round nut in the Decliantion barrel.
Tighten down using the long nosed pliers or
a pair of small screwdrivers.
     
Tightening the Dec barrel set-screws Placing the worm carrier on the Dec shaft Putting the Dec axis back in the main housing
Tighten down the 3 deep set screws on the
Declination barrel.
Replace the worm carrier onto the Declination shaft.
Replace the clear washer on top of the brass
gear. Its almost insivisible in the picture above.
Slide the declination shaft back into the main
housing.
     
Replacing the tapered bearing  Replacing the declination scale Refitting the counterweight collar
Replace the tapered bearing at the bottom of the
main housing after lubricating it with lithium grease.
Note If this wont push all the way in dont worry. As
long as there is some thread showing on the Dec

shaft for the counterweight collar.
Replace the Declination scale on the counterweight
collar.
Replace the counterweight collar. Tighten this down
using only hand pressure. Tighten it as far as it will
go and then back off until the counter-weight lock
lever is in line with the Declination lock
lever.
Note: The threads on this part of the mount can be
very stiff - I applied a small squirt of WD40 to ease
the threads a little.
     
Tightening the counterweight set screws replacing the cap head bolts replacing the Dec lock button
Tighten the 3 set screws in the counterweight
collar.
Replace the cap head bolts (normally silver
coloured) with just enough pressure to hold the
worm carrier in place. Make sure the carrier is lined
up with the mount.
Note: The worm engamement will need to be
adjusted this is covered in the guide HERE.
 Replace the Declination lock 'brass button'.
   
Replacing the Declination lock bolt Replaiving the Declination lock lever Replacing the lock lever screw
Replace the Declination lock bolt. Apply a coat of
lithium grease and hand tighten down.
Replace the Declination lock lever and make sure it
is free to move to both lock and release the
declination axis.
Replace the silver Phillips screw in the Declination
lock lever.
     
replacing the counterweight bar refitting the dovetail holder tightning down the dovetail holder set screws
Replace the counterweight bar into the Declination
axis.
Replace the dovetail mounting. Make sure the
locking screws for the telescope dovetail bar are
oppositethe Declination lock lever.
Tighten down the dovetail holders 3 set screws.
     

At this point you will need to adjust the worm/motor engagement. This procedure is covered HERE.

When worm/motor engagement has been completed proceed to the final step of replacing the motor covers.
Replacing the motor cover  Replacing the motor cover screws
   Replace the plastic motor cover.  Replace the 6 Phillips screws in the motor cover.
 
The Declination axis is now completed. If you wish to strip and adjust the Right Ascension axis go back to the main page HERE