Re: power thermal printer+arduino uno
The Thermal printer we stock (http://www.adafruit.com/products/597
) wants about 1.5A of current. An Arduino and Ethernet Shield can run on 500mA, so the 5v@2A power supply should work for you: http://www.adafruit.com/products/276
That's the same one that comes in the Internet of Things Printer Pack, which has the same parts.
When you void a product warranty, you give up your right to sue the manufacturer if something goes wrong and accept full responsibility for whatever happens next. And then you truly own the product.