Slashdot Mirror

If you want to monitor a serial or parallel port in real time you need an older os like DOS. WinXP, NT and newer made it hard to do this. That is why programs that control stepper motors or gather data through a serial port use some flavor of DOS. That is why some CNC machines use DOS.
For example:
http://www.dakeng.com/turbo.html
http://deskam.com/
http://www.luberth.com/cstep/software.htm

For the numeric control part of your CNC machine you can use the EMC (linuxcnc.com) which is opensource, or you can use Mach3 (artofcnc.com) wich is the paid and much improved version of it for a mere $150, you will receive in support many, MANY times that amount in the 1st months.

Regarding CAM, there are simple converters from vector art to G-Code such as ACE Converter (http://www.dakeng.com/ace.html).

For CAD you got the ad supported version of alibre (alibre.com)

And my last recommendation, goto: cnczone.com and read for hours, there are tons of knowledge there on every aspect of CNC.

BTW, if you are on a short budget, why not build the machine yourself and save some money for an entry level CAM app?

http://www.dakeng.com/turbocnc.html

It works more than well enough for me. I can hold better than 0.001 inch tolerance. BTW, I run it on a 200MHz Pentium. All the motor control stuff is home-made, based on L298 motor drivers.

The real trick is to do it from DOS. If you use windows then the timing has to be done in a real-time external box. DOS is already real-time.

Any old laptop down to about 486DX/33 will be perfectly usable as a homebuilt CNC controller running TurboCNC in DOS. Laptops are actually ideal for this because they don't take up much space, they already have a flat-panel monitor, and they are usually slightly more resistant to accidental thumps and vibration. You do need to have at least a DX, since TurboCNC relies on the math coprocessor. And the parallel port needs to work; it also may require a little buffering since laptop parallel ports can be low-voltage.

For electronic parts, you just can't possibly leave out the Electronic Goldmine. They've been around a long time, and in my experience offer the best surplus stuff you can find while charging the least they can get away with. Their bagged assortments are good, and their Electronic Surprise box is actually a good deal if you don't mind sorting through a box of jumbled parts. They also carry many standard components to round out whatever project you're doing.

If you ever want to build a CNC machine, check out TurboCNC. It's "shareware" in the sense that you are free to download and use the fully-functional, nagless program...and what a program it is. TurboCNC 3 has been used by thousands of hobby CNC'ers, and just recently TurboCNC 4 was released with lots of rewritten code, vastly improved user interface, and better stepping rates. This program will pulse stepper motors up to 30KHz on a junker 486 computer with parallel port, depending on the timer hardware. Version 4 adds Pentium timer support, resulting in pulse rates beyond 100,000Hz. The price rose from $20 to $60 with the release of the new version, but that price is if you feel like supporting Dave and his team, and will get you the full sourcecode to the program.

For cheap PCBs: nobody can beat Olimex. Yeah, they're based out of Bulgaria, and the first setup of payment can be a little tricky. But you'll get a double-sided board with plated holes, solder mask, and silkscreen...about $25 for 6" x 4" board. What's even better is that you can send them a number of files, then give them a sketch of how you want the boards arranged and repeated in the 6"x4" area...and they will panelize and cut them out for you, free. That's impressive if you've ever checked out the costs of doing something similar with other PCB houses. Many of them give the impression that it's like cheating to try to get more than one board out of the standard board size, even if your design only requires a few square inches. With Olimex I've gotten up to ten boards for that cheap price. It kind of makes you wonder what other ways you can use outsourcing, instead of whining about it and trying to make the government give your old job back.

By the way, this list has a long way to go before it's the most exhaustive I've seen. For the ultimate in DIY electronics articles and links, try ePanorama, it's been around a long time.

CNC can be had for much, much cheaper than $100,000. I built my own little CNC machine (bottom of page) from scratch for less than $250. That's not going to mill stone (very fast, anyway) but you can get a full-size Bridgeport or some Japanese mill for under $2,000 in some cases. For another $1,000 or less, and using the mill to build its own parts, you can retrofit the Bridgeport with servo or stepper drives, and use an obsolete desktop computer to control it using free software. Shops also turn over equipment like CNC machines pretty often, in order to keep up with everyone else. An expensive machine pays for itself many times over before it becomes obsolete. You may be able to find an older CNC mill, ready to run, for less than $5,000. I happen to know of one that, if I ever get the space, could be had for under $2,000. For all the information you need, try the CAD CAM EDM DRO Yahoo Group.

On my desktop I use mozilla for browsing the web, zoom player for videos, winamp for music, irfanview for pictures and flash movies, mozilla (again) for mail, Agent and powergrab for newsgroups, and PGP disk to keep it all together and organized (rather than use "partitions" for organizing data I use encrypted "containers" - also known as "files.")

So... what? If MS comes out next week with WM10 and IE7 it'll mean nothing to me; I still have IE5.0 on this box and the only reason I would upgrade to 5.5 is perhaps to install the IBM ecmascript engine, which requires some networking components from 5.5.

MS can come out with Windows-x-b-allodocious if they like - so what? Won't prevent me from using win2k with zoom player, agent, powergrab, pgpdisk and mozilla. Nor will it prevent these old Vectras stacked in the corner from running win2k, or win98, or even DOS (for which there are still plenty of uses).

Sharecropping? I think not. There is a world of "obsolete" and discarded technology out there, and each of us can command our own little heap of it. To quote Fred G. Sanford: "Never underestimate the power of junk."

I absolutely have to put in a plug for TurboCNC.

It really works on machines down to 486-SX33, it has a HUGE and growing user base and support network, it is actively being developed (version 4 almost out!). Best of all, it is free. As in, you can download a the full working program and use it as much as you like. If you want the source code, it's $20. That's a much better deal than any other functional CNC program out there, and you think you'll ever see the source?

EMC is out there, but...forget it. It's clumsy, fragmented, and requires a fast computer. TurboCNC can directly drive steppers at 20KHz...there's even phase drive available, which makes driving bipolar steppers as simple as wiring up a bridge chip and a power supply.

Check it out at DAK engineering. Also take a look at the Yahoo! group at turbocnc.

On titanium rings:

They're not practical for any purpose other than being a wedding ring, and do you honestly need any more purpose? If I ever have need of one, I'm definitely going with the sine wave style.

Dan Statman (of the site you linked) is a member of the TurboCNC community, CNC software that runs on an old 486 with step rates up to 20,000Hz. TurboCNC is being actively developed by Dave Kowalczyk. It's 100% free to use, $20 for the Pascal source. This is for something that can cost hundreds or thousands of dollars elsewhere, and would never run on anything below 400MHz.

Dan Statman built all of his own tools, using TurboCNC to drive his titanium-ring engraver. He quit his job and does this full-time now. He's a regular poster (as am I) in the TurboCNC user group.

It's amazing what you can do with $300 of scrap metal and surplus parts.