A three dimensional printer comprising: a vessel for containing a liquid resin, the vessel having a transparent sheet through which the resin can be illuminated; a light engine disposed to selectively illuminate the resin through the transparent sheet; a fixture for supporting a 3D article of manufacture whereby a lower face of the 3D article of manufacture is immersed in the resin in facing relation with the transparent sheet; a movement mechanism for controllably translating the fixture whereby a vertical distance between the lower face of the 3D article of manufacture and the transparent sheet can be controlled; a sensor configured to monitor a dynamic vertical force on the lower face; a controller configured to: (a) position the lower face of the 3D article of manufacture at an operating distance from the transparent sheet; (b) activate the light engine to selectively cure a layer of resin onto the lower face; (c) repeat (a) and (b) one or more times; characterized in that the controller is further configured to: (d) activate the movement mechanism to translate the lower face upwardly by a distance of D and then downwardly to the operating distance pursuant to a pump cycle; (e) concurrent with (d), monitor a signal from the sensor that is indicative of a dynamic force being exerted on the lower face of the 3D article of manufacture; (f) update at least one pump cycle parameter based at least partly upon an analysis of the signal from the sensor; and (g) repeat steps (a) to (f) until the 3D article of manufacture is completed; and wherein the controller is configured to define the pump cycle based upon a parametric correlation that correlates the pump cycle with at least a geometry of the 3D article. a vessel for containing a liquid resin, the vessel having a transparent sheet through which the resin can be illuminated; a light engine disposed to selectively illuminate the resin through the transparent sheet; a fixture for supporting a 3D article of manufacture whereby a lower face of the 3D article of manufacture is immersed in the resin in facing relation with the transparent sheet; a movement mechanism for controllably translating the fixture whereby a vertical distance between the lower face of the 3D article of manufacture and the transparent sheet can be controlled; a sensor configured to monitor a dynamic vertical force on the lower face; a controller configured to: (a) position the lower face of the 3D article of manufacture at an operating distance from the transparent sheet; (b) activate the light engine to selectively cure a layer of resin onto the lower face; (c) repeat (a) and (b) one or more times; characterized in that the controller is further configured to: (d) activate the movement mechanism to translate the lower face upwardly by a distance of D and then downwardly to the operating distance pursuant to a pump cycle; (e) concurrent with (d), monitor a signal from the sensor that is indicative of a dynamic force being exerted on the lower face of the 3D article of manufacture; (f) update at least one pump cycle parameter based at least partly upon an analysis of the signal from the sensor; and (g) repeat steps (a) to (f) until the 3D article of manufacture is completed; and wherein the controller is configured to define the pump cycle based upon a parametric correlation that correlates the pump cycle with at least a geometry of the 3D article. (a) position the lower face of the 3D article of manufacture at an operating distance from the transparent sheet; (b) activate the light engine to selectively cure a layer of resin onto the lower face; (c) repeat (a) and (b) one or more times; characterized in that the controller is further configured to: (d) activate the movement mechanism to translate the lower face upwardly by a distance of D and then downwardly to the operating distance pursuant to a pump cycle; (e) concurrent with (d), monitor a signal from the sensor that is indicative of a dynamic force being exerted on the lower face of the 3D article of manufacture; (f) update at least one pump cycle parameter based at least partly upon an analysis of the signal from the sensor; and (g) repeat steps (a) to (f) until the 3D article of manufacture is completed; and wherein the controller is configured to define the pump cycle based upon a parametric correlation that correlates the pump cycle with at least a geometry of the 3D article.