keramos Polar Alignment - After setting the offsets (followed the video), I didn't tighten the Alt locking knobs properly, eventually got that sorted
Here is a hint on the ASIAIR (original) polar alignment process...
... if you start polar alignment with the declination axis set to directly above the polar axis (the "counterweight down" position of traditional German mounts), you will find that the altitude lock on the west may be hard to get to (depends on how your OTA and how it is mounted, with/without EAF,... etc) after the mount has slewed the hour angle by 60 degrees.
The trick is start with an hour angle that is "pre-tilted" by about 60 degrees to the east. After the 60º slew, the declination axis is now directly above the polar axis, and gives you maximum clearance of the locking bolts after you have made the adjustments.
As you probably have discovered, the altitude bolt has a big backlash (much worse in my original RST-135 until I upgraded the base a couple of years ago -- my second RST-135 came from the first manufacturing run after the revised base came out). The trick is never to adjust the altitude back and forth. Only turn the altitude bolt in one direction.
That altitude adjuster has a built-in 4mm hex head, by the way, so you can use a 4mm hex T-handle tool that came with the RST-135 to have better control. I use a larger, and longer, 4mm T-hex wrench.
If you overshoot and need to back up, back up well past the minimum, and slowly approach the correct altitude again. Just watch the altitude number and arrow that appear on the ASIAIR polar alignment window. Ignore the graphics, it is rubbish (just like the auto scaling guide graphs in ASIAIR).
Depending on whether your latitude is above 45º or below 45º, there is a preferred direction to adjust the altitude (no difference from legacy German mounts in this regard) -- you want to apply force against gravity (OTA pushes the altitude one way, and adjustment bolt pushes the altitude the opposite way). If the process of locking the altitude (the two side T-handles) moves the altitude, you are probably approaching the minimum from the wrong direction.
Chen
