Using Open Source and CNC?

blueZ3 asks: "I am thinking about purchasing a CNC (Computer Numerically Controlled) milling machine to build small parts to support my hobbies. I'm looking at a machine from Tormach or CNC Masters. These are small, hobby-class CNC mills. Even though I've picked low-cost machines that look interesting, they all require software that adds significantly to the cost of the machine. I've worked with proprietary CAD software before (TurboCAD, AutoCAD) so drawing parts isn't a big deal. But I'd like to avoid spending huge amounts of money on software, when I'm already breaking the bank for the mill. Does anyone out there have experience using Open Source software for CAD that has a relatively 'normal' GUI/interface? Is there a 'mature' CAM conversion software for same? Does anyone want to comment on the intersection of Open Source and CNC?"

Comments

Re:Build Your Own

[HotNeedleOfInquiry]

" The point of CNC machining is precision down to the tenth or half-tenth thousand."

Um, no. The point of CNC machining is to turn out parts cheaper than it can be done by hand. Vast quantities of CNC'ed parts are *not* accurate to a tenth. Often times +/-.001 to .003 is perfectly acceptable and is typical for a production CNC system. Getting closer tolerances than that are usually achieved by honing or lapping.

Specifying overly tight tolerances results in overly expensive parts and assembly problems.