No I haven't, probably mainly because the only time I've used UM in a sentence is in YUM, as in yummy!
But yeah, on these helis, the way I constantly enjoy banging them into things, I'm constantly trying to re-bend everything back into stock "shape". And you're 100% correct, for someone that has bad eyes, and only uses shaky fingers, trying to bend something to within a gnat's arse is PITA.
Being close only counts in:
horseshoes, hand grenades, and RC heli's!