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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.

There appears to be a number of homebrew designs here. One other thing that I noticed from my hour of looking at the subject yesterday is that you need a dedicated computer to control the system. There appears to be Penguin CNC, which seems to do the job, using Realtime Linux.

This may not be what you were thinking when you thought "robot" but it uses all the same control principles. Check out John Kleinbauer's site. He's got plans that are great for a beginner. I purchased his "Brute" plans and the really walk you through every step, from finding the materials to programming. I've changed so many things from the plan since I started building that it's barely the same machine, but the plans helped me to avoid problems I'm sure I would have hit without a framework from an experienced designer to follow. Using PVC, Delrin and aluminum as materials makes the construction fairly easy with a minimum of tools too. For one section where I needed an extra precise cut I had a local metal shop make the cut on their abrasive chop saw for me, but other than that the construction has all been done on the tablesaw and drill press. It's been a fun project.

Find the biggest ugliest old battleship printer at the swap meet. Its apt to be brimming over with usable mechanical parts. You may have to haul the thing away in a truck, but you can probably pick one up cheaper than the gas it takes you to get it home. I've seen sellers get so frustrated trying to rid themselves of an old line printer that they gave it away rather than try to pack it up for the next meet. And the older, bigger, heavier, and uglier it is, the more apt it is to have salvageable parts and powerful motors - because they were made from standard parts before everything was mass-produced for a specific use. As well as being over-designed.

A lot of those old 5 inch floppy drives had a quite decent stepper motor for head positioning that had a standard 1/4" dia shaft. And most had a standard driver chip for the motor too.. those quad-darlington on a chip things. A little inspection on the circuit board usually confirmed how to hook it up.

A side note - if you luck out and get one of those "pancake" spindle motors, some have one helluva disklike planar magnet in them - already mounted in a steel cup. It has a really unique magnetization pattern to it - where it has alternating patterns of North-South on the face that faces the windings. Once removed, it has an extremely powerful attraction. Do not remove it from its cup. Do not even try. You will ruin it if you do. The cup not only mechanically supports the magnet, it also assists in focusing its field. It makes one helluva "refrigerator magnet"! I would advise gluing a piece of felt to it. This magnet will stay where you put it.

Arethan has a post on this forum about some software his dad coded. . I looked at it and it really looks promising. Note it used the standard CNC G-code language and had a really nice port setup so you could drive the interfaces from a pair of standard run-of-the-mill parallel ports. I cite his post because if you are considering rolling your own, you will probably need something like this. This looks like good practical software.

dremel cnc

big links

mini zoltar cnc(using dremel)

Read around on John's website. The best machine to make PCBs (according to him) is the one called "the brute". You can get all the software that you need for free. You can use TurboCAD to design the boards, and other free software to etch them. The software that I mention isn't opensource, but I'm sure such software exists. All you really need to design somehting is a CAD program that can output things in DXF format. Or you could be a REAL geek and write the raw GCODE in vi or something.

You can make a very nice machine for not that much money that has a very nice accuracy. You could do surface mount stuff with it. That said, how many hobbiests base their projects mostly on 88 pin TQFPs? And once you build your machine, all it costs you is a little time and the blank PCBs. That's alot less than $30 a board, especially if you are going to make 10 of 'em.

As for CNC not being easy, it's not easy, but it's not impossible. Especially if all you're doing is PCBs. How expensive is the software? Dirt cheap. You can use the free version of TurboCAD to make your parts. You export them as DXF files. Then the program that controlls your motors can convert that to gcode for you (or you can use another piece of software). You can get free DXF->GCODE converters that work quite well. You can also get free software to run your motors, or nice commercial programs for $20.

It's true that a "real" CNC machines start in the 10s of Ks, but you can make one that will do just about everything a hobbiest will ever need for just a little. For more information see my other posts to this discussion, or see John's website.

If you want to build a machine to mill circuit boards, do it right. Build a machine designed by John C Kleinbauer. The Brute is designed to make PCBs cheaply. I recently bought some of John's plans (well worth it) and they are quite nice. They are very well done, easy to understand, don't need things that are exotic and hard to get (if your in the US). He includes a booklet on how to mill PCBs with The Brute, or you can order it seperatly. He even maintains and activly participates on his forum, Hardware Store CNC.

I've started to build a brute, and things are going pretty well considering I'm doing this in my spare time with only some time to work on it. If you guys are like me (I really like to build things with my hands) this is a ton of fun. I can't wait to get it running so that I can make PCBs, robot parts, a wooden clock and more.

If you want to build a machine to mill circuit boards, do it right. Build a machine designed by John C Kleinbauer. The Brute is designed to make PCBs cheaply. I recently bought some of John's plans (well worth it) and they are quite nice. They are very well done, easy to understand, don't need things that are exotic and hard to get (if your in the US). He includes a booklet on how to mill PCBs with The Brute, or you can order it seperatly. He even maintains and activly participates on his forum, Hardware Store CNC.

I've started to build a brute, and things are going pretty well considering I'm doing this in my spare time with only some time to work on it. If you guys are like me (I really like to build things with my hands) this is a ton of fun. I can't wait to get it running so that I can make PCBs, robot parts, a wooden clock and more.