I am looking to purchase a new CNC machine to turn ID's, OD's, faces, and radius of 120" OD 4140 rolled ring forgings. Can anyone make any recomendations? Also, a machine to drill and tap 1" holes on an appx. 118" BHC for these rings. Any suggestions to manufacturers or models would be appreciated. Thanks!
I can't recommend a manufacture as I'm not certain who is in business anymore. I hope you realize that this would be a one off machine or at the least non stock. Your best be would likely be a vertical turret lathe (VTL), Bullard was an may still be a name with respect to such machines.
The other thing to do is to keep an eye on government auctions as there where a number of very large VTL's owned by uncle SAM. To my knowledge none of them CNC but with this size machine it would make a lot of sense to do a CNC conversion if a frame can be found. I would imagine that fixing up a head on one of these large machines to do the drill and tapping would be easy. Indexing the table is another matter altogether.
The only other option I can see would be a very large bridge mill. In either case you are talking big machinery and bigger dollars new.