How I use the adjuster.
This is a short tutorial of how to tune your adjuster with the benefit of my experiences.
First thing you will need to do is figure out which set of push-pull screws are located where on your monitor or your hair will magically fall out. To do this, place a piece of masking tape near each set of screws and number them 1234 or abcd or whatever suits you. Then de-focus your scope to the point where you can place your hand in front of the corrector plate or lens on a refractor and a obvious shadow shows. Draw a map on a piece of paper or post it note on your monitor so it is easy to remember. Focus the center then check the position of the focus-er. Now go to a spot near one of the push-pull screws and focus that spot while paying attention to which way your focus-er is going. If the focus-er is moving out to focus that area then shorten the distance between the sensor and the lens group by loosening the pull screw and tightening the push screw about half way to getting it in focus. If the focus-er was going in then you need to lengthen the distance by loosening the push screw and then tightening the pull screw. The reason to only go half way to focus is because you are moving the center of frame out of focus at this time. To visualize this, lift a pencil by one end and you will see the middle of the pencil moves half the distance of the end. Some focuser's may be set up different so if this isn't working try reversing the direction. Keep in mind that 1/4 of a turn can bring you into focus and back out the other side so when you are getting close, slow way down on how far you turn your screws.If you are using differential adjusters on your unit then get your unit focused the best you can before you think about the fine tuning as they have such a fine adjustment that 13 revolutions of the fine is equivalent to 1 turn of the coarse. Go slow and move screws 1-2-3-4-1-2 etc. without trying to lock any thing down to much or it will put a bind on things and give you sore finger tips.
I'm sure some clever person will figure out something that is easier and if they do?, please share.