I'm wondering about 2 things before I begin investing time and money in 3D printing? However cool the technology is I really would like to be able to not only print toys.I'm a programmer that have zero experience with 3D design and 3D printing.1) (printer) Say I print a simple tube standing up in the printer, how true is the length going to be? Say 150mm tall and 25mm diameter.15mm bore. can I expect a height difference less than 1mm? Both filament and resin printers.2) (CAD design) Is there cheap software that I could use to design not only a straight tube but one with varying (sp?) outer AND inner diameter while concentric? Like a piece for a woodwind instrument. (plasticwind? )Thanks for any suggestion!