ARM-based CNC mill needs no computer

[Fedeortiz12] and his team are nearing completion of their CNC mill (english translation). They set out to build a standalone machine that takes G-code in the RS274/NGC format from an SD card and machines parts accordingly. At the heart of the system is an ARM LPC2148 controller with a character LCD and control pad for operation. The guys have made a teaser video showing the project being tested with a felt-tipped pen. Take a look after the break.

We’d like to see the final product milling PCBs. We’ve always been a little jealous of the PCB milling setup that [imsolidstate] has in his shop.

26 thoughts on “ARM-based CNC mill needs no computer

  1. The idea was mentioned a while back on CNC Zone forums, I wonder if its the same people. Either way its cool to see it come to life.

  2. theres such cool things to be made with a CNC machine and of course you guys go

    cool lets make circuit boards!!!!!!!!

    maybe we can engrave our names on something too.

    whatever we do lets completely underutilize this technology.

  3. A very impressive piece of kit, but it seems a lot of effort just to make PCBs. The toner transfer method, even with with very basic materials can get you that trace spacing without too much effort.

    http://yfrog.com/3v64pinj is an example I just did using a very basic Lexmark laser printer, a clothes iron and a page of glossy junk mail for the transfer medium. It’s also a TI part, and the pad spacing is also 8 mil. It took about an hour to make, followed by another hour to solder the part without any bridges! If someone could invent an easy way to print solder resist at home, I’d be eternally grateful.

  4. @nes
    “A very impressive piece of kit, but it seems a lot of effort just to make PCBs.”

    You can do more than just drill PCBs with a CNC mill.

  5. cnc mills , no problem, got one, have made circuit boards among other stuff.
    the real kicker here guys , is placing a g code interpreter on a micro-controller. true, you would sneaker net the sd card to it.

    but once you made the g code program, and inserted it, it’s change the material, press go for another one. with no computer resources( or expensive computer programs) dedicated to it.

  6. Verry nice project. But I have to point out to the author that the ARM is a computer ;)

    @nes. Why build a car -when there is the bus?
    I’m pulling your chain… But seriously, G-code is better for circuit boards than PostScript. For holes, or milling many small board from one sheet and so on. There is a whole extra dimension in g-code.

  7. Yes, I see both your points about the usefulness of a mill. I would dearly love to have the use of one. I think the point I’m making is in response to Mike’s comment in his OP about using one for milling PCB traces. Just seems a such a huge effort to me if that is your prime motivation.

  8. I have a dilemma. I could easily design that on solidworks with a bit of time but I couldn’t for the life of me manage to think of it and get it constructed!

    That is a very nice build. ARM = computer – True but still much better than a million watt noisy fan colour screen thing to control the CNC…

    Mowcius

  9. @jamieriddles

    Yes, the heatsinks are necessary and also unrelated to the ARM. They are for the stepper motor drivers.

  10. @sawmill

    Its cool but not really effective at reducing cost that much these days because you can get a computer and monitor for a few hundred bucks at most and use EMC (http://www.linuxcnc.org) to run the mill.

    Despite that it could be used in places where a computer is too large. Like a portable mill for example.

  11. @nes: Loving what you did with the traces there. What did you use to get that “effect”? I’m guessing if I’m using Eagle I’m SOL.

    And I agree that the toner transfer is pretty good at small traces when you need it. I recently made a board using a SSOP package without any trouble whatsoever. Sure, there are packages with tighter spacings but it’s still relatively tight.

  12. EMC2 runs quite well on the ~$100 intel atom boards. It also then gives you options for managing the mill whilst its running and the like.
    Not to diminish what these guys are doing, but the applications I can see for it are outside running a mill. I can see it being used as a motion controller in embedded systems, running hexapods, robot arms and such like. Something with a complex but fairly repetitive behavior where gcode programming would make life much easier than existing plc and ladder logic crap lol.

  13. In what way is an ARM based system with simple display, storage (a FAT filesystem?), etc. not “a computer”?

    Sorry, but the iPhone, my Desktop, the old mainframes, arduinos, and even Babbage’s Folly (this is Ada day) are computers.

    It is impressive, but it still uses a computer.

  14. very impressive, i wussed out and just bought a cnc mill ,but i’m always exicted to see people making their own.
    especially with the arm+SD card rather than just off the shelf,.

    kudos chaps!

  15. Thanks everybody for your comments!

    The heatsinks are for the power stage of the stepper motors but could be smaller. Currently we are recalculating them for the final design.

    Indeed perhaps a cheap atom board could do the trick running EMC2 but:
    1) This was done as a project for a subject where we learn to program uC.
    2) It’s still cheaper to do it this way.
    3) It wouldn’t be as much fun to do!!

    I also would like to mention my friends who are involved:
    Felipe Diniello
    Pablo Garcia

    Greetings!
    Federico

  16. first of all this looks great.
    it is compact,and should have very well timed step and direction pulses.

    suggestions
    add a spindle control relay, having the machine turn the router off has been a great help to me, it lets me know when it is done with its cutting

    big e-stop button (to save the table from a miss placed – sigh or in the lack there of the bit)

    limit/home switches to save time and possibly repairs

    while you are obviously better than me with the electronics the filter caps and the bridge rectifier after the transformer look a little small. i would guess that the rectifier is a 8amp rectifier?

    again great setup

  17. @bud

    Thanks for your suggestions!
    Indeed we are going to implement the following improvements to present the whole thing at our university’s project fair (UTN FRBA in Buenos Aires, Argentina)

    1) Break-out board with a DB25 where we connect our controller, the motor drivers, limit/home switches, emergency stop button and motor drivers.
    2) Hopefully a switching power supply that we are designing now.
    3) Every electronic board and the power supply (except the controller) will go under the moving table protected by a sheet of metal so as to keep everything compact and protected.

    The rectifier is a 10amp one if I’m not mistaken. We used to have another one (it was smaller) when we build the the first wooden CNC but it caught fire. Luckily we have learned from our mistakes.

    Thanks again for your comment!
    Federico

  18. I work at Best Buy and reckoned that you would likely really want to get in on this March promo we’ve been having on newer customer gift cards. Try it out…people are getting oodles of zero cost stuff these days.

  19. Did they run this video in slow-motion? If not, they need some serious patience when they start milling PCB’s.
    If that will ever work, it seemed to have some problems repositioning correctly.
    Or perhaps the paper moved.

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