Abstract: Examples described herein relate to a method of 3D printing. In an example, at least part of a layer of build material is fused. The temperatures of the fused part of the layer are measured at different locations using respective temperature sensors. The temperature sensors are calibrated using the measured temperatures. Heating of additional layers of build material is controlled using the calibrated temperature sensors.

Abstract: An example three-dimensional printer includes a print agent distributor to provide a printing agent to a print bed of powdered build material, a heat source to apply heat over the print bed to form a printed part where printing agent is applied, a heat sensor to measure a temperature of the printed part after heat has been applied, and a processor coupled to the heat sensor. The processor is to determine a target power to be applied to the heat source heat a part to a target temperature in a subsequent printing process. The processor is to determine the target power based on the target temperature, a measured first temperature of a first printed part formed when a first power is applied to the heat source and a measured second temperature of a second printed part formed when a second, different power is applied to the heat source.

Abstract: Certain examples described herein relate to adjusting an energy source of a 3D printing system. In certain cases, a build bed of a 3D printing system is arranged to receive a layer of build material and the energy source of the 3D printing system is controllable to provide energy to a zone of the build bed. The energy provided by the energy source associated with the zone is adjusted based on a difference between a predetermined heat loss of the build bed and a determined heat loss for the zone, where individual adjustments of energy provided to at least some zones of the build bed collectively provide a uniform heat loss across the build bed.