A 3D printer incorporating two angular axes as an inverted SCARA arm and a vertical, linear Z-axis, is described. A platter on which a 3D object is built is rotated around lambda axis and revolved around a lambda axis. Embodiments are described that: (i) are free of belts, pulleys, cables and other soft drive mechanisms; (ii) are free of any lead-screw compensating devices; (iii) are free of rectangular box frame; (iv) translate X-Y-Z voxel coordinates into an angular coordinate system, optionally in real-time; (v) optimize non-sinusoidal drive waveforms for stepping motors; (vi) deal with special cases at or near the lambda axis; (vii) measure and compensate for non-orthogonal platter skew. Both device and method embodiments are claimed.