astro-babys guide to stripping and rebuilding the Synta EQ6/Orion Atlas mount
3 - Synta EQ6 / Orion Atlas - Stripping & Cleaning the Right Ascension (RA Axis


This procedure will guide you in stripping down and cleaning the EQ6 / Atlas Right Ascension axis. Re-assembly of the RA axis is covered HERE.

To carry out this procedure you will need a good assortment of tools including cross head and Phillips screwdrivers, a rubber or nylon mallet, a soft toothbrush,

degreasing agent, metric Allen keys, long nosed pliers, lots of lint free cloths and lithium grease.
I found commercial degreasing agents somewhat ineffective and resorted to using good old hot soapy water. Lithium grease is easily available from shops

selling bicycles. Its also advised to have a large soft towel or similar to lay the mount on while working on it to protect its external finish.

I would strongly advise you do not attempt this procedure without reading it through a few times in advance to understand the process. The procedure takes
around 4 hours from top to bottom (but read the observations at the bottom of this page) unless you are very confident of what you are doing and have exactly
the right tools.
Its definitely best to have someone around to help you with some elements of it - remember take your time and when in doubt STOP and THINK.
Take a break when tired because you don't want to bodge anything.

The DEC and RA worm gear adjustment process required after re-assembly can be quite lengthy as its very much trial and error so bear this in mind before
starting and allow plenty of time to carry out the procedure - it will pay dividends in terms of smooth and precise running and longevity of the mount.

Stage 1 - Stripping the RA Axis
Removing the polarscope cover Using grips to loosen the polarscope removing the polar scope
Remove the polar scope cover. Remove the polar scope. You may need to grip it
with a wrench - if so wrap a cloth around the
polar scope to protect it. Alternately use some
masking tape to protect the scope.
Once loosened simply unscrew the polar scope and
place it somewhere safe.
     
The mount on a soft towel removing the RA lock lever screw RA clutch lever removal
Place the mount on an even surface covered with some towels to protect its external finish. Remove the silver Phillips screw in the RA
lock lever.
Remove the lock lever. You may need to prise this
up by using the tip of a flat bladed screwdriver and
gently twisting the tip.
     
Removing the RA clutch lock bolt Removing the polarscope surround screws removing the polarscope surround
Remove the brass RA lock bolt. You may
need to use a small spanner or pliers. Also remove

the small brass button beneath the lock bolt.
If this is hard to do leave it - it can be removed easily later in the procedure.
Undo the three screws around the polar scope index ring/cover. Remove the polarscope index ring/cover.
Note: Some older EQ6 mounts do not contain an index marker on this component. If your mount does have this marker be careful - its VERY sharp.
     
Removing the RA lock nut set screws Removing the RA jesus nut The RA main nut removed
Slacken the three hex headed grub screws around the polarscope mounting plate. This large component is also the main nut for the RA spindle. Removing the RA main nut using an oil filter wrench.
Note: This bolt is completely smooth and its VERY hard to remove see the observations below.

The RA main nut being removed exposing the RA spindle and the tapered bearing.
     
tapping out the RA axis Removal of the main RA axis block Removing the tapered breaing
Tap the RA main spindle to drive it out. It should move easily but if not then tap it gently with a wooden or rubber mallet.
DO NOT use a hammer as shown in the picture above. This was used only for photographic purposes.
Remove the main RA Axis assembly from the base of the mount.
Note: At this point the small brass button for the
RA locking lever will be easy to push out if you
were unable to extract it earlier.
With the RA main axis removed the tapered bearing at the base of the RA block will simply drop out.
     
loosening the upper worm carrier set screw loosening the lower worm carrier set screw Removing the worm carriuer cap headed screws
Loosen the upper RA worm carrier set screw. Loosen the lower RA worm carrier set screw. Remove the worm carrier cap headed bolts. These were so tight on this mount that a socket set was required.
Removing the RA index scale Removing the RA worm carrier The RA worm gear and associated bearings and washers
Remove the RA scale. This may remove with the main RA block or be left behind on the worm carrier. Remove the worm carrier from the mount. Remove the worm gear from the RA block - the picture shows the RA worm gear with its top bearing removed. Take care to look out for the teflon washers. The mount may have one or two of these. They may be stuck together with grease so exercise care. Place the teflon washer(s) aside and keep them separate from any other washers.
     
Removing the teflon washer from the RA spindle Corrosion on the RA spindle Removal of the EQ6?atlas base main bearing
Beneath the RA worm gear will be another teflon washer. Make sure this is removed and set aside and kept separate from all other washers. With the RA worm gear removed a fair amount of corrosion was observed on the RA spindle along with some rough machining. Its doesn't show well in the photograph above Remove the bearing from the mount base. This can be tapped out using a wooden pole and a mallet in the same way as the DEC housing main bearing shown in the DEC strip down module.
   
Stage 2 - Stripping the Worm Carrier
The RA worm carrier prior to disassembly Removing the RA worm carrier cover Removing the EQ6 worm carrier float adjuster
The picture above shows the worm carrier as removed from the mount. Note the position of the motor gear on the worm - it is not flat against the worms widest point. This is correct. Remove the worm end-caps using some circlip pliers or snipe nosed pliers. You may also be able to remove these with two small allen keys inserted. On this EQ6 these were VERY tight. Remove the slotted nut from the worm carrier using circlip pliers, snipe nosed pliers, two small allen keys or two fine tipped screwdrivers.
The worm carrier float adjuster removed Loosening the RA worm carrier motor gear Removing the worm from the carrier
The slotted nut is shown here removed from the worm carrier. Loosen the motor gear set screws using an allen key. The worm will now simply pull free from the worm carrier.
 Removing the motor gear  Removal of one of the bearings from the worm carrier  The worm and its end bearing
Remove the motor gear from the carrier Remove the worm roller bearing from the worm carrier. Remove the worm roller bearing from the worm.
Stage 3 - Cleaning & Lubrication
EQ6/Atlas bearings and worm gears after cleaning
With a clean lint free cloth wipe all of the oil from the components. On this mount the roller bearings
were sealed and appeared to be well lubricated so were left alone. The tapered bearing had almost no
lubrication and so was cleaned and relubricated with lithium grease.

To lubricate bearings put a blob of grease onto the palm of your hand and press the bearing into it and
then rotate the bearings around forcing the grease into the inside of the bearing.

The brass worm gears and steel worm along with the carrier should all be cleaned in a degreasing agent. I personally find really hot water and a basic detergent works best. These were cleaned with a soft toothbrush and the rinsed and left to dry. All of the gears showed either little lubrication and/or engineering swarf present.

The picture to the left shows all of the components from the RA axis removed, cleaned and lubricated.


Observations:

The RA element of the mount was very hard work to disassemble. The primary problems were removing the main RA nut behind the polar scope
I tried some band grips, mole grips etc. and none of them worked. The bolt should have been protected with a cloth but it was impossible to remove with a cloth on it due to the tools slipping. In the end the bolt was removed with an oil filter wrench which marked the finish. This was touched up during reassembly with some good quality enamel paint.


Further problems were encountered removing the RA main bearings from the RA spindle. Due to some corrosion and lack of lubrication these were virtually seized onto the shaft and it took over 2 hours work to gently tap and drift them loose. As with the DEC axis the bearings, although well lubricated behind their dust shields were almost dry in contact with the mount. The main RA casting bearing was jammed to the RA spindle on removal rather than staying seated in the block. The RA spindle showed signs of rough machining and this was rubbed down using fine emery cloth and wet and dry paper.

The brass RA worm gear also showed signs of damage on its lower face. This was carefully ground out. Although it had no impact on running it looked unsightly. The RA showed little over-painting problem or debris but there was some corrosion along the main RA spindle along with a chalky type of deposit which may have been corrosion or scale of some kind. This was polished off with some very fine emery cloth and wet and dry paper.

Unlike the DEC axis the RA worm interface was clean on the worm carrier but the whole top of the RA block was painted. It was felt better, as the paint was sound, to leave this alone.
 
 
That completes strip down of the Right Ascension axis. If you wish to go to the re-assembly guide click HERE
or go back to the main page HERE