astro-babys guide to stripping and rebuilding the HEQ5 mount
5 - Synta HEQ5 -Worm / Motor Engagement for RA and DEC Axis


This procedure will guide you in setting up the HEQ5 worm engagment and also aligning the motor gears after the Declination and Right Ascension reassmbly. These steps are best carried out with the HEQ5 head mounted onto its tripod or some other type of stable base.

The worm setting procedure - especially for the RA axis is very hit and miss and you will probably need to go through it several time to find the 'sweet spot' where there is both no play in the mount and the RA motor can turn the mount smoothly with no motor stall or gear binding.
 
Worm Engagement for DEC Axis
Lossineing the cap bolts for the DEC axis Lossening the DEC axis upper set screw Loosening the DEX Axis lower set screw
Loosen the DEC axis worm carrier three large silver cap screws JUST ENOUGH so that the small set screws can move the worm carrier. Loosen the DEC worm carrier upper set screw
and...........
.....Tighten the lower DEC worm carrier set screw just enough so that you can feel some play in the axis.
Note: You should loosen and tighten these screws
by approximately 1 quarter of a turn each time.
     
tightening the DEC axis lower set screw tigthetning the DEC axis upper set screw
Now loosen the lower set screw and......... .......Tighten the upper set screw JUST UNTIL
ANY PLAY STOPS.
Note: You should loosen and tighten these screws
by approximately 1 quarter of a turn each time
.
Now tighten down the DEC worm carrier cap headed screws. Work around the screws clockwise tighetning a little each time until fully
tight.
     
Checking movement in DEX axis gears
At this point return to the DEC Assembly Guide or simply replace the Motor Cover.
Remove the motor cover and check that the motor gears can easily move the axis by manually turning them by hand or using the mounts motors. Run the mounts DEC motor a full 360' to make sure there is no binding at any point in the cycle.
If binding occurs you will need to readjust the set screws. This can be a long process to get the perfect balance between no play in the axis and smooth motor running.
 
     
Worm Engagement for RA Axis
Loosening the RA axis worm carier cap screws loosen the RA worem carier upper set screws Tigtening the RA lower set screw
Loosen the RA worm carriers three large silver cap screws JUST ENOUGH so that the small set screws can move the worm carrier. Loosen the RA worm carrier upper set screw
and...........

Note: You will have to remove the power panel to get axis to the upper RA set screw. The panel is retained by two Phillips screws.
.....Tighten the RA worm carrier lower set screw just enough so that you can feel some play in the axis.
Note: You should loosen and tighten these screws
by approximately 1 quarter of a turn each time
     
loosening the RA lower set screw tightning the RA upper set screw
Now loosen the lower set screw and......... .......Tighten the upper set screw JUST UNTIL
ANY PLAY STOPS.
Note: You should loosen and tighten these screws
by approximately 1 quarter of a turn each time
Now tighten down the RA worm carrier cap headed screws. Work around the screws clockwise tighetning a little each time until fully
tight.
     
Checking the RA gears will move freely
At this point return to the RA Assembly Guide or simply replace the motor cover and the power panel using the Phillips screws.

Take care when replacing the power panel not to trap any wires.
Remove the motor cover and check that the motor gears can easily move the axis by manually turning them by hand or using the mounts motors. Run the mounts RA motor a full 360' to make sure there is no binding at any point in the cycle.
If binding occurs you will need to readjust the set screws. This can be a long process to get the perfect balance between no play in the axis and smooth motor running.
 
     
End Float Adjustment
Removing the worm float cover adjusting the  worm end float replacing the worm float cover
Remove the soft rubber covers to reveal the end
of the worm shaft and float adjuster.
Loosen the float adjusted using either a small
jewellers screwdriver or a small allen key to locate into the adjusters slots. You should feel the some play in the axis. Now tighten the float adjuster down until any play disappears. The float adjuster should be in contact with the worm bearing but not overtight or else the axis will 'bind'
Replace the rubber worm float covers
Motor Gear Adjustment
HEQ5 motor alignment
The HEQ5 Motor gears should all be flush with each other as shown in the picture to the left. The gears should be closely fitted but not pressed together too tight to prevent excessive gear wear.

REMEMBER one of the gear set screws must be against the flat of the worm spindle.

The gears in my mount are liberally coated with Lithium grease to reduce wear and also to muffle running noise.
 


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