3D printer, comprising: a construction box system, comprising: a construction box having a side wall structure and a construction platform received within the side wall structure, the side wall structure limiting an upwardly open construction box interior space for building a component by 3D printing, the interior space being downwardly limited by the construction platform; and a support structure comprising its own drive integrated into the support structure and to which the construction box is releasably attachable, so that the construction box can be repeatedly removed from the support structure after building the component in the construction box interior space and subsequently reattached to the support structure, wherein the drive integrated into the support structure comprises a travel drive for moving the support structure, which is configured to move the construction box system between a first position, in which the construction box system is arranged for building up the component in the 3D printer, and a second position, in which the construction box system is arranged outside the 3D printer, and a coater for application of particulate material in layers onto the construction platform and/or a print head for selective printing of the particulate material using a binder jetting method. a construction box system, comprising: a construction box having a side wall structure and a construction platform received within the side wall structure, the side wall structure limiting an upwardly open construction box interior space for building a component by 3D printing, the interior space being downwardly limited by the construction platform; and a support structure comprising its own drive integrated into the support structure and to which the construction box is releasably attachable, so that the construction box can be repeatedly removed from the support structure after building the component in the construction box interior space and subsequently reattached to the support structure, wherein the drive integrated into the support structure comprises a travel drive for moving the support structure, which is configured to move the construction box system between a first position, in which the construction box system is arranged for building up the component in the 3D printer, and a second position, in which the construction box system is arranged outside the 3D printer, and a construction box having a side wall structure and a construction platform received within the side wall structure, the side wall structure limiting an upwardly open construction box interior space for building a component by 3D printing, the interior space being downwardly limited by the construction platform; and a support structure comprising its own drive integrated into the support structure and to which the construction box is releasably attachable, so that the construction box can be repeatedly removed from the support structure after building the component in the construction box interior space and subsequently reattached to the support structure, wherein the drive integrated into the support structure comprises a travel drive for moving the support structure, which is configured to move the construction box system between a first position, in which the construction box system is arranged for building up the component in the 3D printer, and a second position, in which the construction box system is arranged outside the 3D printer, and a coater for application of particulate material in layers onto the construction platform and/or a print head for selective printing of the particulate material using a binder jetting method.