权利要求：
CLAIMS:
1. A method for determining a production of a luminaire (100) via 3D-printing, wherein the luminaire is intended for vertical suspension, the method comprising the steps of defining a suspension point (110) of the luminaire, the suspension point being an exterior point of the luminaire by which the luminaire is intended to be vertically suspended, defining a fixation line (120) through the luminaire, the fixation line elongating from the suspension point and being parallel to a vertical axis, z, defining a plurality of cross-sectional shapes (130) of the luminaire along the vertical axis, z, wherein each cross-sectional shape of the plurality of cross-sectional shapes extends in a plane, P, perpendicular to the vertical axis, z, and corresponds to a 3D-printing layer of the luminaire, and for each cross-sectional shape of the plurality of cross-sectional shapes of the luminaire: a) defining a fixation point (140) as the intersection of the fixation line with the cross-sectional shape, b) defining a mass balance line (150) in the plane, P, wherein the mass balance line intersects the fixation point, c) defining a first side (160a) and a second side (160b) of the cross-sectional shape with respect to the mass balance line, respectively, wherein the first side and the second side are arranged opposite to each other with respect to the mass balance line, d) defining a sector angle, dcp=l 80°/n, wherein n is an integer, wherein for each angle <p=A- dtp. wherein =1, ... , n e) determining an extrusion of 3D-printing material of the cross-sectional shape as a function of a first sector, Si, of the sector angle, dtp, at the angle, cp, in the first side, wherein the first sector, Si, is associated with a first mass, mi, of extruded 3D-printing material, and
a second sector, S2, of the sector angle, dcp, at the angle cp+180°, in the second side, wherein the second sector, S2, is associated with a second mass, m2, of extruded 3D-printing material, for minimizing a distance, Ro, between the fixation point and a center of mass, Mt, of the first sector, Si, and the second sector, S2, and in case the distance, Ro, exceeds a predetermined threshold distance, Rt, 1) defining a connection line (170) in the plane, P, intersecting the center of mass, Mt, and the fixation point, wherein, in case the center of mass, Mt, is located in the first side, determining an additional extrusion of 3D-printing material of the cross-sectional shape in the second side such that a first center of mass, Msi, of the determined additional extrusion of 3D-printing material of the cross-sectional shape of the second side coincides with the connection line in the second side and is located at a first distance, Rsi, from the fixation point, for minimizing |MsrRsi-MfRo|, and wherein, in case the center of mass, Mt, is located in the second side, determining an additional extrusion of 3D-printing material of the cross-sectional shape in the first side such that a second center of mass, Ms2, of the determined additional extrusion of 3D-printing material of the cross-sectional shape of the first side coincides with the connection line in the first side and is located at a second distance, Rs2, from the fixation point, for minimizing |Ms2’Rs2-MfRo|.
2. The method according to claim 1, wherein the determining of an extrusion of 3D-printing material is based on a track width, tw, of extruded 3D-printing material perpendicular to a direction of extrusion of the 3D-printing material.
3. The method according to claim 1 or 2, wherein the luminaire is intended to be at least partially hollow, and, in at least one cross-sectional shape of the plurality of cross- sectional shapes, is intended to comprise at least one layer of 3D-printing material in a radial direction of the cross-sectional shape.
4. The method according to claim 3, wherein the luminaire, in at least one cross- sectional shape of the plurality of cross-sectional shapes, is intended to comprise a single track of 3D-printing material.
5. The method according to claim 4, wherein the step of determining the extrusion of 3D-printing material comprises, based on an intended extrusion of 3D-printing material along a first chord length, Ah, of the first sector, Si, with a first track width, twi, of the 3D-printing material, and along a second chord length, Ah, of the second sector, S2, with a second track width, tW2, of the 3D-printing material, determining a first ratio, Ri, between the first track width, twi, and the second track width, tW2, such that Ri=(p2-Ah-r2)/(prAlrri) is fulfilled, wherein n is the sector radius of the first sector, Si, n is the sector radius of the second sector, S2, pi is the density of 3D-printed material along the first chord length, Ah, and p2 is the density of 3D-printed material along the second chord length, Ah.
6. The method according to claim 3, wherein the luminaire, in at least one cross- sectional shape of the plurality of cross-sectional shapes, is intended to comprise a plurality of tracks of 3D-printing material.
7. The method according to claim 6, wherein the step of determining the extrusion of 3D-printing material comprises, based on an intended extrusion of 3D-printing material along a plurality of first chord lengths, Ahi, of the first sector, Si, wherein the plurality of first chord lengths, Ahi, comprises an innermost first chord length, Ahi, and an outermost first chord length, Ahn, with respect to a first sector radius, n, of the first sector, Si, and along a plurality of second chord lengths, Ahi, of the second sector, S2, wherein the plurality of second chord lengths, Ahi, comprises an innermost second chord length, Ahi, and an outermost second chord length, Ahn, with respect to a second sector radius, r2, of the second sector, S2, determining a second ratio, R2, between a first density, pi, of the first sector Si, and a second density, p2, of the second sector S2, such that R2=(A12nT2c-Ar2)/(AhnTic-Ari) is fulfilled, wherein An is the radius length between a center point of the innermost first chord length, Ahi, and the outermost first chord length, Ahn, An is the radius length between a center point of the innermost second chord length, Ahi, and the outermost second chord length, Ahn, ncis the radius from the fixation point to a first center point, Cri, of a first area, Ai, defined by Ahn and Ari, andcis the radius from the fixation point to a second center point, Cr2, of a second area, A2, defined by Ahn and An.
8. The method according to claim 7, wherein the step of determining the extrusion of 3D-printing material is further based on an intended extrusion of filler material between the intended extrusion of 3D-printing material of the first sector, Si, with respect to
21 the first sector radius, n, of the first sector, Si, and on an intended extrusion of filler material between the intended extrusion of 3D-printing material of the second sector, S2, with respect to the second sector radius, r2, of the second sector, S2.
9. The method according to claim 1 or 2, wherein the luminaire is intended to be at least partially solid, and, in at least one cross-sectional shape of the plurality of cross- sectional shapes, is intended to comprise a plurality of tracks of 3D-printing material.
10. The method according to claim 9, wherein the step of determining the extrusion of 3D-printing material comprises determining a third ratio, Rs, between a first density, pi, of 3D-printing material of the first sector, Si, and a second density, ps, of 3D- printing material of the second sector S2, such that Rs=r22/ri2is fulfilled, wherein ri is the sector radius of the first sector, and rs is the sector radius of the second sector, S2.
11. The method according to any one of the preceding claims, wherein a fourth ratio, R4, between a maximum track width, twmax, and a minimum track width, tWmin, of extruded 3D-printing material, respectively, perpendicular to a direction of extrusion of the 3D-printing material, fulfills R4 < 3.
12. The method according to any one of the preceding claims, wherein a minimum track width, tWmin, of extruded 3D-printing material fulfills 0.1 mm < tWmin < 1.6 mm.
13. A 3D-printing apparatus for production of a luminaire (100) via 3D-printing, wherein the luminaire is intended for vertical suspension, comprising a printer head comprising a printer nozzle, configured to extrude a 3D-printing material, and a control system coupled to the printer head for controlling an extrusion of the 3D-printing material, wherein the control system, based on a suspension point (110) of the luminaire, the suspension point being an exterior point of the luminaire by which the luminaire is intended to be vertically suspended, a fixation line (120) through the luminaire, the fixation line elongating from the suspension point and being parallel to a vertical axis, z, and a plurality of cross-sectional shapes (130) of the luminaire along the vertical axis, z, wherein each cross-sectional shape of the plurality of cross-sectional shapes extends in a plane, P, perpendicular to the vertical axis, z, and corresponds to a 3D-printing layer of the
22 luminaire, is configured to, for each cross-sectional shape of the plurality of cross-sectional shapes of the luminaire: a) define a fixation point (140) as the intersection of the fixation line with the cross-sectional shape, b) define a mass balance line (150) in the plane, P, wherein the mass balance line intersects the fixation point, c) define a first side (160a) and a second side (160b) of the cross-sectional plane with respect to the mass balance line, respectively, wherein the first side and the second side are arranged oppositely each other with respect to the mass balance line, d) define a sector angle, dcp=l 80°/n, wherein n is an integer, wherein for each angle <p= r- dtp. wherein =1, . . . , n e) determine an extrusion of 3D-printing material of the cross-sectional shape as a function of a first sector, Si, of the sector angle, dtp, at the angle, cp, in the first side, wherein the first sector, Si, is associated with a first mass, mi, of extruded 3D-printing material, and a second sector, S2, of the sector angle, dip, at the angle cp+180°, in the second side, wherein the second sector, S2, is associated with a second mass, m2, of extruded 3D-printing material, for minimizing a distance, Ro, between the fixation point and a center of mass, Mt, of the first sector, Si, and the second sector, S2, and in case the distance, Ro, exceeds a predetermined threshold distance, Rt,
1) define a connection line (170) in the plane, P, intersecting the center of mass, Mt, and the fixation point, wherein, in case the center of mass, Mt, is located in the first side, determine an additional extrusion of 3D-printing material of the cross-sectional shape in the second side such that a first center of mass, Msi, of the determined additional extrusion of 3D-printing material of the cross-sectional shape of the second side coincides with the connection line in the second side and is located at a first distance, Rsi, from the fixation point, for minimizing |MsrRsi-MfRo|, and wherein, in case the center of mass, Mt, is located in the second side, determine an additional extrusion of 3D-printing material of the cross-sectional shape in the first side such that a second center of mass, Ms2, of the determined additional extrusion of 3D-printing material of the cross-sectional shape of the
23 first side coincides with the connection line in the first side and is located at a second distance, Rs2, from the fixation point, for minimizing |Ms2-Rs2-MfRo|.
14. A computer program comprising computer readable code for causing a computer to carry out the steps of the method according to any one of claims 1-12 when the computer program is carried out on the computer.