I’m not sure if you’re looking for an actual machine printer that you’d buy yourself to print your own books or you’re looking for a "printer" as in a company that provides a "print on demand" service.
An actual machine printer for "print on demand" is very large and expensive, but a "print on demand" service is also available. Basically do a Google search for "print on demand" and look for what you’re looking to actually do.
I’m not sure if you’re looking for an actual machine printer that you’d buy yourself to print your own books or you’re looking for a "printer" as in a company that provides a "print on demand" service.
An actual machine printer for "print on demand" is very large and expensive, but a "print on demand" service is also available. Basically do a Google search for "print on demand" and look for what you’re looking to actually do.
Below are a few links that may be of help:
http://www.printondemand.com/
http://www.bookmarket.com/ondemand.htm
http://www.xerox.com/digital-printing/printers/print-on-demand/enus.html
http://www.writing-world.com/publish/POD.shtml
Best of luck.