Patent attributes
A three-dimensional printer includes a light engine, a support plate, and a resin vessel. The light engine is configured to selectively harden photocurable resin at a build plane in the resin vessel. The support plate is formed from cast metal and is in a fixed vertical relation to the light engine. The support plate includes an upper side with an upstanding ridge. The upstanding ridge has an upper datum surface that has been machined to a controlled height. The support plate also includes a separately formed ring disposed upon the upper datum surface. The separately formed ring defines a crest of the upstanding ridge. The resin vessel includes a transparent sheet that defines a lower bound for resin contained in the resin vessel. The transparent sheet impinges upon the crest to define a vertical location of the build plane in relation to the light engine.
