AZ-3 Servicing part 2

Tweaks and tips to get the most out of your Synta AZ-3 mount.

By Antony McEwan

Nuts'n'Bolts

The altitude tension nut essentially holds the whole assembly together. Before attempting to remove that, I undid the screws that hold the altitude rack to the assembly, which meant that the unit then swings completely loose with nothing holding it in place. The tension nut was then removed and discarded. I threw it away as it should be a self-locking nut, and once removed they never seem to attach to the same tension again. Why? I have no idea, but for the cost of a packet of lock nuts from a hardware store I can afford to live in ignorance. There were then several washers of varying materials, all coated in Syntaglue. I removed them one by one, cleaned them, and put them in a special place where I’d remember them - in sequence! Then, the central bolt simply slid out of the housing, and I’d disassembled the altitude section. Everything was gloopy of course, so everything got cleaned in the same way as before.

The altitude and azimuth racks were cleaned using the WD40/washing up liquid/toothbrush method and then a spot of Castrol added to each. I then rotated the drive unit using the slow-motion control several times to make sure the new grease was evenly applied along the length of travel. Even at this stage the motions seemed smoother…

I then laid everything out in a logical order and had a cup of tea.

Reassembly Is The Reverse…

I now had everything laid out, cleaned and re-lubricated with proper grease where appropriate, and ready to be put back together. It did look a little bit daunting, but I’d placed everything in logical places, and so it was only a ten-minute job to reassemble the altitude section. All seemed to be going well. I decided to place the clutch ring section on the tripod head first as it would hold it steadily in place while I attached the top section of the mount to it. I did this, and rotated the clutch ring around the tripod mount several times to make sure the new grease was evenly applied. Then the top section of the mount (with the altitude section) simply slotted back in place, with the central bolt passing through the whole upper assembly. The nut underneath the tripod was reattached and tightened, and the altitude section was reattached to the altitude adjustment pinion. Phew! It does sound complicated, but as I said before, it was easier to do than to write about. With everything stuck back together again I noticed that there were no ‘spare’ bits lying around – always a good sign!

I played with it for a while, spinning the mount around and adjusting the altitude up and down to make sure that the lubricant was evenly applied and the motions were smooth. They were - much more so than they were initially, and there were no horrific squelching noises either! The final task was to adjust the tension adjustment nut.

Because the nut is a lock nut, it’s best to adjust it to the correct tension under the conditions that it will be used in. I attached the telescope tube, finder and diagonal so that the adjustment would be made under the normal operational loadings that the mount would experience. Then it was a matter of tightening the nut slightly and manually adjusting the altitude of the ‘scope up and down through the full range of travel to see if it was too loose or too tight. If too loose, the nut was slightly tightened again and the procedure repeated. This was done again and again until the telescope tube was still easy to move in altitude, but would stay in position when my hand was removed.

After that, I used the slow-motion controls to make sure that the telescope would go where I wanted it to with no stickiness or slop. After about fifteen minutes of playing, testing and adjusting, I was happy with the result. The tube would stay pointed at any angle without slipping, and could still be manoeuvred smoothly by using the slow motion controls.

The way the AZ-3 mount is used is interesting. The amount of ‘travel’ the slow motion controls will give is limited by the length of the altitude and azimuth pinions, hence the need for coarse ‘manual’ control as well. The idea is that you position the tube roughly by hand then lock the azimuth clutch and use the slow-motion controls to track the target object across the sky. Every now and then, when the end of the travel allowed by the racks has been reached, the user must move the tube manually again and ‘reset’ the pinions to allow further tracking. It doesn’t take much effort to learn and is not hard to do at all. The slow-motion tracking feature is very useful when using medium or high power magnifications too.

This little project took very little time and effort, and gave a great improvement to the product. This AZ-3 will now be much more usable, with smoother motions and steadier support. Not bad for two hours work…

Click here to go back to part 1.

Click here to go to AZ-3 Counterweight Mod part 1.