The best way to do this is to start with about 1mm of spacing. Just zero it out, and turn all of the fine thread screws an equal amount. They are very precise and distance is repeatable, so count how many rotations you do, and apply that equally to all corners. Then lightly snug the locking screws. Run your analysis (single frame or hyperbolic curve or NINA or visual... whatever) and determine which corner is the worst.
I recommend that you only try to fix one corner at a time. Always go for the worst one. Once you have found the worst corner, loosen the lock screw as well as the lock screw for the corner diagonally from that one. Leave the other two corners lock screws lightly snug. You need to loosen the locks on the two opposite corners where you are working. If you move one of those corners out, you are applying an inverse movement on the diagonally opposite corner... so it needs to be able to move in.
So if you turn one of the fine thread tilt screws clockwise 1/4 turn, you need to turn the diagonally opposite fine thread screw 1/4 turn counter clockwise. You are basically pivoting the plate on the diagonal between the two locked corners. Then lightly snug those two locking screws down and repeat your analysis.
If a fine thread screw is tight and does not easily turn.. dont force it. you need to loosen the remaining locking screws slightly. Sometimes only 1/8 of a turn is all you need. There is something binding and you need to relax the force. Dont loosen it enough so the plate begins to float. The Axial design of the current Octopi version is less likely to bind than the original version with the radial arrangement of screws. If you loosen the screws so much that the plate can float, you run the risk of it sagging into an undesirable position when you lock things down. If you do accidentally do this, point at the zenith so gravity pulls evenly on the device and gently snug the locks back down to pickup where you left off. It might be better to do all of your adjusting while pointing up, however with a refractor its not convenient to reach the adjustments, so I generally aim north and have a camp chair behind the scope to sit in.
The key with all of this is to move slowly and be gentle with the screws.
EDIT- And dont forget to loosen the screws on the sides of the Octopi, as mike mentioned above.
EDIT 2- When you need to make a backspacing adjustment, which is an equal adjustment to all corners... point at the zenith like described above, let gravity be your friend while adding or removing spacing.
Edited by ChrisWhite, 01 June 2024 - 09:42 AM.
