Build your own Mini Metal Maker: 3D print with metal clay, ceramic, chocolate, stem cells, or whatever! Paperback – 31 Mar. 2016

built this machine with the help of this book very clear instuctions,easy to follow,

This is a very thin book. It assumes that you already have a 3D printer to make the required parts. It has some blurry photos to illustrate a few (mostly obvious) points, but is particularly vague about the absolutely crucial extruder element. Basically, it seems that you buy a syringe and hack it so that perhaps it might work (that's about the same level of detail as the book). It also requires that you use a very specific part number for the motors. Are there alternatives? You're on your own. Very disappointing.