I don't want to give much advice about modifying a glider.... If your glider is already set up for kingpost hang then it shouldn't fly a whole lot different from keel hang point. It just gives you a little more control power, which is welcome in double-surface wings with long span. No difference in flair technique. I guess you'll notice more power to rotate the nose up but I don't know how this would make any practical difference in flair technique, the flare timing really shouldn't change unless you also have trimmed for a different airspeed than you had before. Most pilots prefer to hang as near the base bar as possible, like maybe one fist above the base bar.
If your glider is already set up with kingpost hang then there will be several possible positions (either by moving the king post or by moving the bolt that secures the hang strap.) Start near the middle-- or if you are heavy start further forward or if light start further aft-- same ideas as with keel hang.
Checking the trim speed is the same as with keel hang. Do you know how to check for min sink speed by watching telltales mounted on the top of the sail? If you want to trim for min sink in wings-level flight then these telltales should be just starting to reverse at trim. Trim being the weight of your hands on the bar but no muscle force. If you prefer to trim faster (or slower), modify accordingly....
This is all pretty standard stuff. Maybe I am missing some part of your drift....
If you are trying to modify a glider for kingpost hang and want to know how high to drill the hole, I don't know what to tell you, copy some other glider? You'd want the hang point to be vertically above your old keel hang point when the glider is in a "normal" pitch attitude, but I can't tell you how to estimate a "normal" pitch attitude, except by propping up the glider and raising or lowering the back as you hang from the keel till the bar ends up in the same place as it is in flight, that should be a normal pitch attitude. Maybe much better to ask someone else who has done the same mod on the same glider? How often is this sort of mod ever done in actual practice, if the glider wasn't designed for kingpost hang from the start?
It seems there will be a real possibility the kingpost simply won't be in the right place (fore-and-aft) to allow successful modification to kingpost hang unless you know this has been done successfully with this glider--
Andrew wrote:Hello group!
I am looking for online info about the nuances of hanging from the kingpost (as opposed to keel based hang points).
Something that will help me determine the best length AND the best point between nose and tail to hang from. Also proper flair technique and trouble shooting "symptoms" of improper hang point.