Hi,
that is a good size. There is no doubt that the larger the machine the costs go through the roof.
Of all the parts that you need the costliest and most difficult to get are the ballscrews. If you want genuine ground (C5 or C3) screws from the leading manufacturers like NSK, THK
expect to pay $1000 to $1500
each for them.
In another thread some guys have been advocating TBI screws which they reckon are ground and the specs certainly support C5 specs at a fraction of the cost, say $250 vs $1500. Quite frankly I'm
dubious that the claims are correct......but if you want C5 or C3 at bargain prices....you'll have to decide for yourself.
Other than that you'll have to buy secondhand or new old stock. Very good parts can be had but you'll almost never find the exact right thing, so you get what you can and make a machine to use what you can get.
I buy from:
https://www.ebay.com/str/industrialp....m47492.l74602
For my machine I bought three 32mm diameter 5mm pitch double nut (BNFN) C5 (genuine ground) THK ballscrews and six THK FK25 fixed mounts including shipping to New Zealand for $1000USD.
If I had bought new they would have cost close to $10,000USD. It certainly made my project possible....I'd never have been able to afford to buy new.
Servos are not cheap, but man do they kick arse!!! You are right to get servos. I think 400W would be adequate, but 750W would be supreme. My machine has a 750W Delta B2 series servos on each (5) axis
and a built-in electromagnetic brake on the Z axis. They cost $438USD a piece (plus shipping) but they sure are good.
Craig