A modular lathe bed system is provided including various lathe designs for incorporating the modular lathe bed into a lathe. The bed system includes a machine mounting block design which may be used to support the lathe headstock, cross-slide, and tailstock. A sliding lock system secures and stabilizes the machine mounting blocks, allowing them to slide or be locked in place. The machine mounting blocks move on a modular way bed including two upright bed tracks. The bed tracks and their connecting structure allow for a modular and extendible way bed.