Man, that's so true. It's crazy how the smallest thing being off can throw the whole system out of whack. Makes you respect the engineers who get it perfect on the real things. That shake must have been frustrating to figure out on your model. Did it take you long to find the sweet spot for the balance?
That 'smallest thing' point is spot on. I had a 3D printer that would shake and mess up layers if the bed wasn't perfect. Took me three days of tweaking to realize one corner was a millimeter too high. I just kept tightening and loosening the screws until it stopped. Used a piece of paper to check the gap on all four sides. Now it runs like a dream.