" for someone like me, with no electronics background "
uhhhh .. ok. (if you say so)
very nice work such as yours will advance the art and raise the bar. because once one gets past intuitive acts such as setting engine timing by ear and amp/volt adjustments when welding , things need quantification if they are to advance further.
(just exactly What things are worthy of this quantification is a place where conventional management most often falls on it's face, being as they tend to look at the clock rather than the quality.)
i am not so sure that the arms are necessary for accuracy, but then, Right There is some intuitive thinking, and it's not backed up by squat.
if i was to do anything different, the first thing i might add is ferrules to my wire ends. they render wire connections more user friendly, easier to move about, and they look cleaner. also, ferrules are essentially Free. virtually All the nicer industrial equipment wiring is equipped with them. econo stuff .. not so much..
such are avail @
you'll want the appropriate crimping tool. once you go with ferrules, (it's like wiping down your ammo, even though it just came out of a new box) your life will be better, and you will stand taller among men.
thank you for sharing !