Nuts print without rafts. The tower itself can be printed without supports, but with a raft. If you print it big side down, use supports. You may need to clean up the leading thread edge on the small side if printed the original way (large side up). Use at least 75% infill with PLA, 3 shells, 5 layer floors and ceilings.
This is a remix of mbergin's original. All I've done is split the models using Netfabb, and scaled the nuts up 2% to address a mis-fitting issue.