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Build Your Own PCB Milling Machine

mwandel writes "It used to be that one off amateur printed circuit boards were all etched in acid. A lot of companies nowadays use a special form of milling machine to mill them out of solid copper clad circuit boards. This guy Jonathan Westhues built his own PCB milling machine out of various parts, with a laminate trimmer as the milling head. Lots of other neat hacks on his Webpage as well."

20 of 210 comments (clear)

  1. Comment removed by account_deleted · · Score: 4, Informative

    Comment removed based on user account deletion

  2. milling machines are cool by zymano · · Score: 3, Interesting
    If you type in "home built milling" at google you'll get an interesting type of mill called a CNC mill that is made out of regular Dremel rotary drills and computers. Very cool.

    More people need to be able to make their own parts out of steel and plastic. The problem is cost. It's curious that a country that is inventive as ours doesn't have some type of affordable CNC(computer numeric computation) milling machine.

    Affordable metal cutting lathes are expensive too.

    1. Re:milling machines are cool by UniverseIsADoughnut · · Score: 3, Interesting

      ""The problem is cost. It's curious that a country that is inventive as ours doesn't have some type of affordable CNC(computer numeric computation) milling machine.""

      You underestimate what it take to make a good mill. A none computer controlled Bridgeport Vertical Mill will set you back 16 grand depending on how you option it. There are not a highvolume thing. It takes massive peices of perfectly machined metal to do this. Theres a lot to it. You can't just cheapen one up without it becomeing well cheap.

      Adding Computer Numeric Control is not so easy. Though i'm sure if someone wanted to do it it would not be impossible. But there is a heck of a lot to G code (what runs CNC's). You'll be working the bugs out for a while. And then you still need a CAD program to pop out G code, thats a few grand there at the cheapest level. Granted if you want to spend a lot of time you can code it by hand. Many machinist do much of the G code by hand, but they do that everyday.

      There are reasons CNC's aren't cheap, Mainly the fact everything about them is expensive. If you ever get to see a real high end CNC mill or lathe going you will understand why the cost $100K to a million bucks. Watching one at work will blow your mind. Especialy if you stick your head in it.

    2. Re:milling machines are cool by MBCook · · Score: 4, Interesting
      Good try, but not quite. If all you want to do is mill simple things and etch circuit boards with it, it's not that hard. There are a few little bits, but you can build a good one for under $100 (plus steppers, etc). It would cost less if you already have some of the stuff around.

      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.

      --
      Comment forecast: Bits of genius surrounded by a sea of mediocrity.
    3. Re:milling machines are cool by madfgurtbn · · Score: 4, Informative

      See www.desktopcnc.com for a comparison of various tabletop cnc machines. Depends on your personal definition of "affordable", but there are some small machines $3k

      I don't think you could reach .0001 tolerance on those low-end machines, but most of them would get close to .001, which is plenty for most hobbyist projects.

      --
      Send lawyers, guns, and money. Dad, get me out of this.
  3. There are easier ways by John+Jorsett · · Score: 4, Informative

    Seems like a lot of trouble to go to when it's pretty cheap to get small-quantity custom boards done.

    1. Re:There are easier ways by lirkbald · · Score: 3, Informative
      A couple others to try:

      ExpressPCB- Has an offer that will let you make 3 3.8"X2.5" 2-sided boards for about $60, as well as a more general off that's not too much more pricey. They have their own board design software you have to use, which is a bit primitive but adequate for hobbyist use, though it's a problem if you were to ever want someone else to make your boards.

      Advanced Circuits- Has a deal to make 2-sided boards for $33/ea, min qty 3. These boards have a solder mask, which is required for dealing with fine-pitch SMT parts, and makes your board all pretty and professional-looking ;-)

      Sierra Proto Express- Has a similar deal to Advanced Circuits, but also has a good price to make four-layer boards.

      Some general notes- I've used the first two, and it worked alright, but I haven't tried the third one. The latter two require Gerber and Excellon data- this is the standard format for PCB plotting and drilling information information. Essentially any board layout software should be able to generate them. However, it is not trivial to figure out what precisely to send the board manufacturer- you can't just blindly trust your layout software to do the Right Thing. I keep meaning to write a little tutorial on my hard-won knowledge about this, but I've never gotten around to it :-/

    2. Re:There are easier ways by Ratso+Baggins · · Score: 5, Insightful
      You may be missing the point, he machine's turn-around-time is 1 hour(ish) the best you can get is 1 day from the fab co's. Secondly @$80 a board you will quickly pay for the milling machine, if you have need for it. I like it because @ 1:00am when I'm ready to do the board - I can... and how many things geek are done "because I can"?

      Granted it's only double sided - but at that it's wonderful. Wow, no more chemicals! I've always-forever wanted one of these but the pro milling machines are out of my league.

      --

      --
      "we live in a post-ideological world..." - Billy Bragg.

  4. Re:Amateur by bjcubsfan · · Score: 4, Informative

    They're still called PCBs even if they are milled. It's a naming convention that has stuck. It is in no way incorrect.

    Also, It is not difficult to make a double sided PCB with a milling machine. There are many times in circuit board design that you don't need more than one or two layers. This is a solution that solves a lot of smaller problems every day.

  5. Do It Right - John Has Great Plans by MBCook · · Score: 4, Informative
    note: the site is down, so I'm going off a mirror of the front page of the site, sorry if I get things wrong

    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.

    --
    Comment forecast: Bits of genius surrounded by a sea of mediocrity.
  6. Acid etching is nearly extinct by green+pizza · · Score: 3, Interesting

    Good article for those that don't already have access to PCB milling equipment. There really is no reason to do the old-school etching method anymore, in fact, I don't even know any hobbyists that do that anymore. Milling equipment can be found, borrowed, or made pretty easily these days. I've even seen a working setup made from Lego Mindstorms and a cordless Dremel! Hey, it works and beats the heck outta the mask-and-acid roll of the dice method.

  7. Electronics Enthusiasts... by Kevin+Burtch · · Score: 4, Insightful

    It seems dabbling in electronics is a dying hobby for the younger crowds... I hope projects like this spawn new curiosity and interest.

    For those new to this hobby... here are some publications that could be of great value to you:
    http://www.nutsvolts.com/
    http://www.circui tcellar.com/
    http://www.poptronics.com/

    Anyone know of any others?

    --
    - Preferences: Solaris 10 (servers), Ubuntu (desktops), Solaris 11 (personal servers) -
    1. Re:Electronics Enthusiasts... by Smidge204 · · Score: 4, Informative

      How about sources for new/surplus components?

      http://www.goldmine-elec.com/
      http://www.alltro nics.com/
      http://www.allcorp.com/
      http://www.new ark.com/
      http://www.jameco.com/

      Try to never buy from Radioscrap. Overpriced and crap quality...

      I've ordered from Alltronics before. They have a $15 minimum order, and sometimes an order may be delayed if something you requested is out of stock. They answer your e-mails rather quickly, though.

      Jameco also sells the seemingly elusive PCI prototyping cards, though they're pricey ($70). Anyone know another supplier of these? (They're also good if you're looking to pick up a 266MHz PII motherboard for $20)

      =Smidge=

    2. Re:Electronics Enthusiasts... by Thatmushroom · · Score: 3, Interesting

      As one of the members of the younger crowd of which you speak, I'd like to express my own (personal) opinion.

      I'm certainly curious, and the multiple articles about home-made tools for dabbling with electronics certainly contribute to my curiosity. The problem, however, is two-fold. One, some of this is rather daunting for most beginners. I see some of the talk about people on here building their own circuitboards and such, and I'm a little intimidated, frankly. Two, I wouldn't know why to dabble in electronics, and the lack of an interesting and simple project just means that I won't get the basics that would let me move on to more advanced projects.

      www.nutsandvolts.com certainly looks like an interesting resource, but I'm not sure it's as good for complete newbies such as myself. I'm going to sign up for a sample issue to better evaluate it, but I'm still afraid I'll miss a lot of critical background information.

      --
      You zap the moderators with a wand of humor! The moderators resist!
    3. Re:Electronics Enthusiasts... by Kevin+Burtch · · Score: 4, Informative

      Well, there used to be Electronics Now and Popular Electronics (which merged, and became Poptronix), but the printed publications are gone (to my knowledge). You may be able to find all the old issues at your local library... although ones over 1 year old may be only on microfische.

      As much as I'm annoyed with Radio Shack for turning into a toy and appliance store (they used to be an electronics hobbyist store), they do still have a handfull of items for the electronics tinkerer.
      I'd recommend picking up all of their Engineer's Mini-Notebooks to start with.
      I'd also recommend checking out some of their X-in-one kits... I think they have a 300-in-one now (I hope they haven't stopped making these).
      They have all kinds of example circuits that you can make by hand wiring (read: no soldering) the circuits together - and some of the examples are kind of cool for a beginner. I started with a 150-in-one kit (it was the biggest at the time) way back when I was a teen.

      After this... if you want to get into digital electronics, pick up the TTL Cookbook and CMOS Cookbook by Sam's.
      If you want to get into audio electronics, pick up the Audio IC OP-Amp Applications (also by Sam's).
      If you're a musician, there's a VERY cool one called Electronic Projects for Musicians by Craig Anderton. Use this one with the above audio book to come up with some really cool guitar effect "pedals".

      I hope this helps!

      --
      - Preferences: Solaris 10 (servers), Ubuntu (desktops), Solaris 11 (personal servers) -
  8. Isn't it a salt? by shoppa · · Score: 3, Informative
    were all etched in acid

    Isn't Ferric Chloride (the stuff you buy in bottles at Radio Shack, or at least I did when I was a kid) actually a salt? FeCl... looks like a salt to me!

    1. Re:Isn't it a salt? by Paul+Neubauer · · Score: 5, Informative

      Yes, it is a salt. Copper is more reactive than iron, so the etch works by the chlorine trading iron for copper. The "filings" left after etching are the iron that was freed in the reaction.

      Some folks see it anything that 'eats' away at something as being caused by an acid, even if no acid is really involved. Wouldn't it be nice if chemistry was taught? And taught in a way that was effective?

      --
      I don't subscribe to RMS's GNUtopian vision.
  9. Re:Amateur by uglomera · · Score: 5, Interesting

    Milling machines are not an overkill or a solution for amateurs, they are a very good solution for inexpensive prototypes or production needed in small-mid volume.

    Acid etching produces a functional board, but it simply does not look good, and you can't make 100 boards that are exactly alike. The lines are almost straight, the edges are not perfect, and if you are on a contract to deliver a product, this is not an option. Examples of where a milling machine is one of the best solutions: a university lab where the researchers are under government/industry contract and are supposed to deliver a working prototype or a small business with a military contract (small volume products).

    I worked for a startup company for a while, and part of my job was to work on a QuickCircuit milling machine, and that thing had milling bits that were 4 mils thick (comparable to hair). You can hardly reach this precision with acid etching. I also adapted the machine to dice wafers, which replaced the company's practice of using an exactoknife :)

    If you are in the IC design business, testing cheaply is of primary importance. You can get a full setup for producing boards for less than $10K. How's that compared to billions of $$$ for setting up an IC production plant? And if you are in the RF design business, you need the precision so that a crappy board does not screw up your high-frequency measurements.

    Of course, milling is no option for producing high-volume PCBs with many layers, but don't think that ASUS spent months to design such a board to test their new motherboard design. First they have to verify that design works, which is done with a cheap PCB design, one that would hook up the ICs. Only after that stage can the final PCB design begin.

    As long as the Z80 or 68K processors are still in use, simple PCBs will be here, and we need a cheap and fast way to design and make them.

  10. And for the real, hardened professional. by Jennifer+E.+Elaan · · Score: 3, Interesting
    Actually, you missed the secret of the really high-volume people. Photoresist is actually primarily for rapid prototyping, not production. Due to the harsh nature of etchants, there are very few compounds that are both photosensitive and resistant to them. Most of them are quite dangerous.

    The most serious problem comes in from the really high-end etching systems. Photoresist is fine with ferric chloride, but when you start using something like an acid-peroxide etchant, it will actually eat many "resist" inks. The resist pens become TOTALLY useless, for example.

    And so this is where the old technique of serigraphy comes in. This is the "screen-printing" that makes the name Printed Circuit Boards. The resist ink used on the actual board is usually just some form of lacquer, which holds up well to even the harshest etchants. A stencil is prepared on a screen, usually through a photographic process. Since the screen resist doesn't have to deal with the same harsh chemicals, it is generally much more environmentally conscious and cheaper than PC-Board photoresist.

    I actually set up to do this method myself, in a semi-hobby context. I had some previous experience with serigraphy, and the acid/peroxide system was cheaper, far more effective, and much easier to dispose of than the ferric chloride. On the flip-side, it will eat virtually anything metallic and smells aweful (it isn't much of a health hazard except in the sulphuric/peroxide system, but should be ventilated nonetheless), so it's not for the faint of heart.

  11. pretty unfortunate by RestiffBard · · Score: 3, Informative

    This is one of the cooler "News for Nerds" articles I've seen in a while and its completely unreachable at 4 in the morning because of the slashdotting.

    this is no longer humorous. As much as I often enjoy the +4 comments on certain articles reading slashdot is pretty much no longer worth the frustration of not being able to RTFA.

    Can't wait till this article moves down the frontpage.

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