@efficientAF:
Will do! I think my initial choice was something along the lines of, "NEMA 17s are common on smaller lighter weight machines, so I must need something bigger" 🙂
At present I have 2 of the same NEMA 23s and 1/2' lead screws for my Z, but if I go for a more radical redesign, I'll be offsetting as much weight from Y onto Z in which case the extra 23s will be handy as I'd likely have 4 on Z at that point. However since there is no correlation between noise and weight, this change would be to speed up print time and improve quality/reduce corner ringing. It'd be a pricey change so I'll keep that one in my back pocket in case it comes down to that.
It's common for people to "overspec" their builds - my thought processes were the same when I started out. I've seen many, many designs which on paper seem to be the "dogs danglies" - huge motors, big fat multi start ball screws, big wide steel reinforced belts, or the other end of the spectrum with Cartesians using super lightweight heads, carbon fibre parts, etc. It's a bit like building a 4x4 hill climbing, off road capable vehicle or a super light weight high powered racing car for taking the kids to school on a flat road in a 30mph speed limit. Ultimately, we are limited by how fast we can melt filament, which in turn limits the printer speed that we can actually use.
Ref ringing on corners - forget it. With the mass you have, the resonant frequency will be so low that you won't get ringing (one useful side effect of having heavy axes).
