you can sorta yse old printer step drivers. for a '3d printer' you do not actually have a physical contact, so the printers can be much smaller.. you dont even need a Z axis for a zcorp style machine, just a big vat of plaster powder(they use plaster, or starch.. plaster seems easier to deal with)
an HP II clunker has a decent motor in it, but the shaft is a nasty gear.. anyways, to use old printer driver boars, you probably have to build the phase circuitry, or better, program a PIC. most printers, like the HP II have these large driver transistor arrays, you can leave the power supply in tact and the connections to the board, and jumper in your own drive circuitry..
uhm... an idea, you could maybe just use a inkjet gantry mechanism, and hope the ink is enuff to cause the plaster chemical reaction... write software that cuts a 3d model into subsections and uses a regular windows print driver to print each page... a custom something-or-other could be done to make the tray of powder drop one level.. i believe the zcopr uses plaster with some filler... its common knowledge what the filler is.. do some research..
the main advice is to get 3 xylotec boards if you dont like the inkjet idea... which i think is promising..
good luck
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