3-D printer in polar coordinates

1. A 3D printer for printing buildings and structures, comprising:

a. a base;

b. wherein the base has a telescoping-type lift mechanism;

c. a rotation mechanism coupled to the telescoping-type lift mechanism so that a height of the 3D printer connected to the rotation mechanism only can be adjusted in an XOZ plane;

d. wherein the base and the telescoping-type lift mechanism do not rotate;

e. an extendable boom arm having telescoping extendable sections mounted to the rotation mechanism;

f. the extendable boom arm being capable of translational and rotational motion in an XOY plane;

g. an extruder at the end of the telescoping extendable sections for extruding a concrete-based chemical solution;

h. wherein the 3D printer automatically prints a building or a structure based on a given design schematic;

wherein:

the rotation mechanism has an inner housing and an outer housing which surround a concrete based chemical solution feed pipe and have a bearing unit between the inner housing and outer housing allowing the inner housing and outer housing to freely rotate around each other;

mounted to the inner housing are a plurality of contactor rings in electrical communication with a plurality of contactor antennae that are mounted to the outer housing;

the inner housing has an electrical terminal that is an inner housing end which is in electrical contact with the plurality of contactor rings;

the plurality of contactor rings are mounted to non-conductive inserts and are not in direct electrical contact with the inner housing;

the outer housing has an electrical terminal that is an outer housing end which is in electrical contact with the plurality of contactor antennae; and

the plurality of antennae are mounted to non-conductive inserts and are not in direct electrical contact with the outer housing.

2. The 3D printer for printing buildings and structures of claim 1 , wherein the extendable boom arm has a counterweight mechanism, on an opposite end of the extendable boom arm from the extruder, a position of the counterweight mechanism is automatically adjusted so a center of mass of the 3D printer coincides with an axis of rotation of the 3D printer.

3. The 3D printer for printing buildings and structures of claim 1 , wherein the extendable boom arm having the telescoping extendable sections has a maximum operating radius of 20 meters.

4. The 3D printer for printing buildings and structures of claim 1 , wherein the concrete-based chemical solution is pumped through the rotation mechanism, then through the extendable boom arm, then through the telescoping extendable sections and finally through the extruder by a pumping unit connected to the rotation mechanism by a pipe or a hose.

5. The 3D printer for printing buildings and structures of claim 4 , wherein the concrete chemical solution is under an operational pressure of up to 40 bars.

6. The 3D printer for printing buildings and structures of claim 4 , wherein the concrete chemical solution is regulated between 0 to 120 liters per minute for extrusion.

7. The 3D printer for printing buildings and structures of claim 4 , wherein a flow rate of the concrete chemical solution varies in relationship to a trajectory of the extruder changing.

8. The 3D printer for printing buildings and structures of claim 4 , wherein the 3D printer and the pumping unit are controlled by a control unit housed in the base of the 3D printer, the extendable boom arm, the pumping unit, or in a separate ancillary control unit.

9. The 3D printer for printing buildings and structures of claim 4 , wherein the concrete-based chemical solution is stored in a storage unit, or provided by a transport truck that pours its contents into a trough or a feeding unit for the pumping unit.