Apparatus and method for accurately leveling a build plate

A three-dimensional printer comprising:

• a resin vessel;
• a build plate positioning mechanism including a pair of L-shaped brackets that individually include:
• a fixed vertical portion constrained to vertical motion;
• a movable portion that coupled to the fixed vertical portion, the movable portion including a lateral lower end;
• an adjustment mechanism configured to adjust and set an angular position of the lateral lower end with respect to the fixed vertical portion;
• a plurality of lower datums arranged upon the pair of L-shaped brackets;
• a build plate having a plurality of upper datums configured to engage and align to the plurality of lower datums when the build plate is placed upon the pair of L-shaped brackets;
• the plurality of lower datums having an arrangement upon the pair of L-shaped brackets which enables the adjustment mechanisms of the pair of L-shaped brackets to provide an independent angular adjustment of the build plate along two lateral axes;
• a vertical movement mechanism configured to position the fixed vertical portion along a vertical Z-axis;
• an imaging subsystem configured to selectively cure layers of photocurable resin above the build plate;
• and
• a controller coupled at least to the vertical movement mechanism and the imaging subsystem.

A method of manufacturing a three-dimensional (3D) article comprising:

• providing a 3D printing system including:
• a resin vessel containing photocurable resin;
• a build plate positioning mechanism including a pair of L-shaped brackets that individually include:
• a fixed vertical portion constrained to vertical motion;
• a movable portion that coupled to the fixed vertical portion, the movable portion including a lateral lower end;
• an adjustment mechanism configured to adjust and set an angular position of the lateral lower end with respect to the fixed vertical portion;
• a plurality of lower datums arranged upon the pair of L-shaped brackets;
• a build plate having a plurality of upper datums configured to engage and align to the plurality of lower datums when the build plate is placed upon the pair of L-shaped brackets;
• the plurality of lower datums having an arrangement upon the pair of L-shaped brackets which enables the adjustment mechanisms of the pair of L-shaped brackets to provide an independent angular adjustment of the build plate along two lateral axes;
• a vertical movement mechanism configured to position the fixed vertical portion along a vertical Z-axis;
• a motorized wiper;
• an imaging subsystem configured to selectively cure layers of photocurable resin above the build plate;
• operating adjustment mechanisms of the pair of L-shaped brackets to independently level the build plate about two lateral axes;
• operating the vertical movement mechanism to position an upper surface of the build plate or 3D article one layer below a build plane;
• operating the motorized wiper to level resin over the build plane;
• and
• operating the imaging subsystem to selectively cure the photocurable resin at the build plane;
• repeat operating the vertical movement mechanism, the motorized wiper, and the imaging subsystem to complete fabrication of the 3D article.