  3D print is a recently developed technique, for single-unit production, and
for structures that have been impossible to build previously. The current work
presents a method to 3D print polymer bonded isotropic hard magnets with a
low-cost, end-user 3D printer. Commercially available isotropic NdFeB powder
inside a PA11 matrix is characterized, and prepared for the printing process.
An example of a printed magnet with a complex shape that was designed to
generate a specific stray field is presented, and compared with finite element
simulation solving the macroscopic Maxwell equations. For magnetic
characterization, and comparing 3D printed structures with injection molded
parts, hysteresis measurements are performed. To measure the stray field
outside the magnet, the printer is upgraded to a 3D magnetic flux density
measurement system. To skip an elaborate adjusting of the sensor, a simulation
is used to calibrate the angles, sensitivity, and the offset of the sensor.
With this setup a measurement resolution of 0.05\,mm along the z-axes is
achievable. The effectiveness of our novel calibration method is shown.
  With our setup we are able to print polymer bonded magnetic systems with the
freedom of having a specific complex shape with locally tailored magnetic
properties. The 3D scanning setup is easy to mount, and with our calibration
method we are able to get accurate measuring results of the stray field.
