The construction of a permanent magnet based 3D encoding system for an Ultra-Low field MR is presented and its initial characterization is presented. Proposed system moves a single permanent magnet along a prescribed helical path as proposed in our previous numerical study. This initial prototype is built to fit an existing ULF-MRI human extremity system. Preliminary results are in good agreement with the simulations. However, further studies are needed to identify the sources of error and improve the precision of the field estimations towards a practical encoding system.