Robotic positioning device for three-dimensional printing
  Additive manufacturing brings a variety of new possibilities to the construction industry, extending the capabilities of existing fabrication methods whilst also creating new possibilities. Currently three-dimensional printing is used to produce small-scale objects; large-scale three-dimensional printing is difficult due to the size of positioning devices and machine elements. Presently fixed Computer Numerically Controlled (CNC) routers and robotic arms are used to position print-heads. Fixed machines have work envelope limitations and can't produce objects outside of these limits. Large-scale three-dimensional printing requires large machines that are costly to build and hard to transport. This paper presents a compact print-head positioning device for Fused Deposition Modeling (FDM) a method of three-dimensional printing independent from the size of the object it prints. 
Sasa Jokic, Petr Novikov, Stuart Maggs, Dori Sadan, Shihui Jin,   Cristina Nan
cs.RO