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

At least you can save the price of the OS

[the_illuminatus]

Weber Systems makes a cad/cam package that runs on Linux. In fact, their windows versions use cygwin! Some of the system is written in bash, and you can at least try it out for a while. http://www.webersys.com/linuxsynergy.htm

Re:At least you can save the price of the OS

[Directrix1]

Has anybody checked out the open source BRL-CAD before? Apparently its pretty mature, and the military uses it.

Build Your Own

[MBCook]

If you have some tools, you can build your own quite cheap and make a great machine. A guy named John C. Kleinbauer sells plans on his website for a couple of different machines. Once you buy plans, you get access to his "inner circle" BBS (can't remember the name) where he personally supports his plans, he and other members talk about their machines, what they are building, tips, etc.

It's a great little community.

By going this way you can save cash on the machine to buy the software, but they also mention software you can use that is either cheap or free.

Re:Build Your Own

[Phronesis]

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

That's just not true. I do a lot of CNC at 0.005" or coarser tolerances. CNC is also great for turning out lots of repetitive work (drilling and tapping thousands of holes for optical breadboards, turning out dozens of widgets). CNC is also good for complex curves. On the other hand, if I'm machinging rectalinear or circular surfaces and want 0.00001" tolerances, I can do as well by hand with a good solid machine. That way, I can set up compound slides to give me good precision and measure between each cut.

Just because some CNC machines are good for some high-precision work doesn't mean either that CNC is the best way to do any precision job or that CNC is only valuable for doing precision work. CNC can be hugely useful for some loose-tolerance work and some high-tolerance work is better done manually. It's often a question of whether it's faster to create and check the routing code or to cut manually.

Re:Just buy the software

[QuantumG]

If you are going to invest that much, why worry about the cost of software?

How about worrying about your freedom?

BRL-CAD?

[LWATCDR]

http://brlcad.org/
I don't know if it will export IGES but it might. If not Turbocad is pretty cheap.

http://www.linuxcnc.org/

[RGRistroph]

Not for designing the parts, but for controlling the machine during the run:

http://www.linuxcnc.org/