A brief overview with images of how I cleaned both the RA axis as well as the Dec axis on my G-11, relubed everything and put the mount back together.
After several years of usage I noticed that gears became a bit sticky and I decided to take apart the mount to clean everything.
I have done this twice so far. Below shows an overview of how to disassemble the important bits of the G-11.
First a word of warning:
Below overview in images shows merely how I undertook the process of taking apart both RA and Dec axis, cleaning and relubing and then putting everything back together.
Please note that this is always done at your own risk. This is not meant to be a tutorial or a guide how to take apart your own G-11 mount.
This mount is a precisely machined piece of equipment and disassembling and re-assembling should be done with care and precaution.
Each image below is clickable and will show a larger version in a separate window.
Before you start working on the mount make sure you are prepared.
Get some old cloths for cleaning and prepare cleaning liquids and tools, see the images below for specific details.
Start by getting several old cloths and unplug all cables to the mount.
(Yes I know some cables are still attached in below image 😉
Make sure the Dec head rests on the RA motorhousing as shown below BEFORE unscrewing the counterweight bar and releasing the clutch !
WD40, white lithium grease, refined petrol/white spirit and alcohol. Alcohol is only used for plastics, all other parts are cleaned with petrol.
A small lid to clean washers in and some old toothbrushes for scrubbing of the smaller parts and needle bearings.
As soon as preparations are finished we can get to work on the Dec axis.
In pratice it is not important if you start with RA or Dec first, the process is more or less the same, it is just the way I set up below overview.
Images are in chronological order by the way showing disassembly step by step.
After unscrewing the counterweight bar take off all parts and washers at the end of the Dec axis. Note the order of the washers. Clutch knob, wave washer, thick spacer, normal washer, needle bearing washer and a normal washer.
Clean the top part already and remove the declination setting circle.
There is more grease after removing the declination setting circle.
Use petrol to get rid of all the old grease (and accumulated dust and pollen)
Declination after scrubbing and cleaning.
As if it was just being assembled in the factory, no signs of use whatsoever.
The standard greyish grease.
You can now gently remove the dec assembly from the housing. No need to remove the polar scope knob plug in the middle of the housing.
View of the needle ring bearings inside the dec housing.
Use an old toothbrush to clean these and remove the old thick grease. Dry after cleaning.
Take off the worm block cover by unscrewing the (very) small Allen screws on the side facing you.
This exposes the worm assembly and coupling for the next step.
Another view of the fully cleaned Dec housing
Note the nylon washer/disc; there should be NO grease on the nylon disc at all as this washer generates the friction between the metal parts locking the clutch. The grease is smeared onto the dec shaft by the needle bearings inside the housing.
Looking through the dec housing.
There are 2 sets of needle ring bearings, 1 at the top, 1 at the bottom. Make sure you clean both.
Loosen the large Allen screws at the bottom of the worm block and remove the worm.
It is connected to the motor via a “oldham coupler”, you can just unclick the worm block from the coupler leaving just the motor.
Newly relubed Dec with white lithium grease. I use this grease because temperature does not influence the properties of the grease, in other words it will not thicken when getting cold. Not sure if I overdid it with the grease, but better safe than sorry.
Clean off the grease first from the metal shaft, then remove the nylon disc.
Use the alcohol for cleaning the nylon disc. There should be no grease on the disc
Clean all washers with petrol in the small tin lid. Dry well before reassembly.
Prior to the upgrade to Gemini I was using the regular motors (SAIA Burgess) shown here.
Loosen both small metal tubes to the left and right.
Take special care as there is also a tiny plastic washer (see image in the RA section) on the threaded end, make sure you do not loose it !
I cleaned all metal surfaces and bearings with the refined petrol and the alcohol was only used for just the plastic parts (the 2 nylon discs)
After cleaning and relubing every part make sure to put it back together in the exact opposite manner.
Make sure you press the worm assembly against the wheel but do not overtighten as this may cause the motors to stall under load. You should be able to move the wheel by turning the oldham coupler without resistance, make sure you minimise any play between the wormblock and wormwheel without overtightening !
Check this by tightening the clutches after reassembly and feel if there is any play in the dec axis.
Do not worry if you do not get it perfect at first try, you can always finetune this after everything is finished.
Now that we have the Dec axis finished, we can start with the RA axis.
Again images are in chronological order showing disassembly step by step.
You may find some steps and components similar to the Dec axis, as there are many common components and similarities in set up.
The procedure is more or less the same due to the way the mount was constructed.
Start by unscrewing the polar scope (if installed) from the RA axis.
As with Dec clean the metal shaft first, then remove the nylon disc and clean using alcohol.
Taking special care not to loose this tiny plastic washer on both sides of the motor !
RA with all of the top part (see previous imae_ removed. No need for regreasing here.
Uses a special type of blue grease, no idea what this is. Did not clean nor regrease anything.
Now take off the cluch knob and washers from the RA axis. Note the amount, type and order is exactly the same as the Dec assembly.
Unscrew the small Allen screws to the left and right of the motor housing in order to remove it.
Clean the cover taken from the top of the RA housing.
RA assembly fully cleaned and relubed with white lithium grease.
As with Dec everything is now loosened and you can gently remove the RA housing from the mount.
Loosen the Allen screws at the bottom of the RA head and remove the top cover.
Clean the complete top of the RA housing. You could take it also completely off (see next image) but this is not entirely necessary. Take care as this part is a very tight fit.
Another view.
Clean the top part of the housing.
Unscrew the small metal tubes to the left and right of the motor.
Top part of the RA housing, note the large needle bearings. Part was still in pristine condition, no dust or any other pollution found, no regreasing needed.
Exactly the same applies for RA as Dec.
After cleaning and relubing every part make sure to put it back together in the exact opposite manner.
Make sure you press the worm assembly against the wheel but do not overtighten as this may cause the motors to stall under load. You should be able to move the wheel by turning the oldham coupler without resistance, make sure you minimise any play between the wormblock and wormwheel without overtightening ! – This is even more important for RA as this directly impacts the tracking performance of your mount !
Check this by tightening the clutches after reassembly and feel if there is any play in the dec axis.
Do not worry if you do not get it perfect at first try, you can always finetune this after everything is finished.
As there are some parts which are more likely to be worn out then others, for example the 2 large nylon washers/discs and the wave washers, please find below a direct link to the Losmandy.com spare parts list were these items can be ordered directly from the manufacturer.
Losmandy.com – spare parts list > Direct link to Losmandy spare parts list
You could also try if any local or European dealer is keeping stock of these parts to minimise transport lead times.
