we have a 2000 love it and we set the off contact on every job and here is why.....
we have Newman MZX frames some we bought new some we bought used.
Depending on how deep the square bar sets into the clamp head
depending on how perpendicular the side tubes are to the square tube
depending on how some of the registration posts are standing a little higher than others
depending on how good you are at getting the platens parallel, level and all the same with those freaking bolts and the double nut arrangement that attach the platens to the press arms........
bottom line there are too many variables to expect once you set the off it is good to go on all.
some tips........
on the off contact bolts don't back them off so they are real loose.
we leave them snug enough that if we are moving the head down we need to push it down, if we are raising it we need to crank a bit on the knobs . Otherwise yes there is a bunch of movement that will change you settings when you tighten all up.
On the locking levers, kind of the same thing, yes with the load of the screen on the head clamp it will sag and when you sock down the locking levers it will pull up changing your OC.
You need to set your pallets up all the same.
Throw a screen or plexi-glass or even a 12 x 12 floor tile in one head and jerk around with the bolts on the pallet bracket to dial them all in the same to that one head and the item you have clamped there.
Once you have that done you need to check OC on every job again because of the variables mentioned above.
At the end of the day it is like putting on the same green but from a different angle and distance each tim...no two puts are the same and no two screens will ever associate with the pallet the same every time.
Learn to manage the variables and all those knobs are your friends.
mooseman