I'm blowing the cobwebs out of my mom's 1986 Ward's (Happy Sewing Co) machine. I have been watching videos of setting timing:
adjust timing until the hook passes through the scarf...
...and how to set the needle bar:
adjust needle bar height until the hook passes through the scarf...
(I'm paraphrasing)
It sounds like you could take a perfect machine, then lower the needle bar 1mm, then compensate by delaying the hook 30 degrees, and you'd have the hook passing through the scarf at the correct spot... yet it would be all wrong.
Is there a way to set needle-bar height independent of the hook timing?
Like, obviously the needle needs to rise a few millimeters to make the slack thread form into a loop behind the scarf, ready to be caught by the hook. Is that amount of rise kinda-sorta consistent across machines from a given era?