02-03-2026, 11:31 AM
When I work on mechanical tachs or speedos, I pull the tip of the needle over the resting stop peg and the needle will settle into a "negative" area. I then mark the spot with tape, or take a photo, so I can replace it to the proper spot before winding it up and putting it back over the peg stop. These gauges use spinning magnets, and a fine wire spring to dampen the motion, and the preload is necessary.
