[q. "I planned on trying to hack an inkjet to try to work, the viscosity of the thermoplastic concerned me. I was going to take a shortcut and copy/modify Stratasys's Liquifier pump first as I really would not have to change that much, my first thought was a high temp peristaltic pump."…
"Precison is MY current problem, My Kossel Mini works, however, I cannot really create too many function parts to my standards...which may be a tad ambitious."
Inkjet/Polyjet does not use Themoplastic. It uses UV curable polymers. These polymers can be really "nasty" to work with, they also can be prohibitively expensive. The design paradigm of the multifab was based on the openfab machine. The problem with having a machine that will do both cnc machining and printing is that for the printing you want low mass in the head and gantry with high acceleration movements and for machining you need high mass low acceleration for holding any kind of tolerance in the part. I don't believe a multi-machine utilizing the same gantry for both processes will ever be a valid solution. Next, when you finish comprehending Miss Kwans thesis on inkjet drive electronics you will find a few more problems. Hacking the Drop on Demand (DoD) control of the Epson inkjet heads is a real pita! I began to see that the Multifab was really a frankenprinter that many students at csail under the guidance of Matusik had used to write and prove their thesis and was not ever really a finished product that could be built for $10k; the head used in the 2013 thesis is not even available anymore.