Additive + Subtractive = One Powerful Machine

It says it right on the title of the video below: it was bound to happen eventually. It’s only natural that somebody would stick a 3D printer extruder on the business end of a CNC machine. The long-awaited convergence of additive and subtractive manufacturing is here.

OK, that may be overstating things a bit, but we think [Chris DePrisco] is on to something here. Given the considerable investment he’s made in his DIY CNC machine, an enormous vertical machining center that looks a little like a homebrew Bridgeport, it was a no-brainer to take advantage of the huge XYZ stage. Mounting the Titan Aero extruder to the quill required some custom parts; fair warning that the video below is heavy on machining, but it’s not the seven hours of video he streamed when he milled the heated aluminum bed. Skip ahead to about the six-minute mark if you want to see the first prints and how he optimized the setup.

As we watched [Chris]’ video, we were struck by the potential for adding 3D printing to CNC milling machines. What we’d like to see is a setup where the spindle and the extruder work together to build more complex parts. Or maybe a tool-changing CNC that can pick up a spindle, an extruder, and maybe even a laser or plasma cutter head. Now that would be a powerful machine!

We’ve been here before, almost. With this CNC machine and a 3D printing pen.

[via r/CNC]

26 thoughts on “Additive + Subtractive = One Powerful Machine

  1. “It says it right on the title of the video below: it was bound to happen eventually. It’s only natural that somebody would stick a 3D printer extruder on the business end of a CNC machine.”

    Commercial machines?

  2. So, have hackaday writers been living in a friggin cave lately? This has been done MANY MANY MANY times since the dawn of 3D printing. It is so un-new its pitiful.

    1. Yeah. CNC mill -> 3D printer RepStraps are as old as the RepRap project, and I wouldn’t be surprised at all if some early FDM 3D printers from the ’80s were converted mills.

  3. I have made a setup that gets a 3d printer and a laser to work together (print a part, then laser-burn a logo on it), it was a couple years ago, I sent you the data and it was bit bucketed I guess :) I’ll have to put it back together sometime.

  4. In general this is a bad idea because the kinematic requirements of milling and 3d printing are so different.

    Milling requires a very heavy and rigid structure which is not well suited to producing zigzag infill at 120mm/s.

    Useful CNC mills are expensive enough that you might as well spend another 2-10% of your budget on a discrete printer. A discrete printer is likely to produce equivalent prints much faster, can be used at the same time as the mill, and you aren’t wasting time swapping the mill back and forth.

    1. as with anything, material determines the speed you need to run at. yes plastics do need 120mm/s feed rates but wait, some cnc mill machines run at 20 m/min (
      with a conversion that is about 333 mm/s not to mention the fact that other commercial machines are already doing this with metal:

      mazak has this,
      Metal powder laser sintering:
      Wire arc (mig welding):

      i really think you should do some updated reading on what exactly cnc Mills are capable of. and as for home machines well that is just a factor of what motors you get to move the parts. They may cost more but bigger motors are able to move a heavier and stiffer structure with a higher speed while not trading away accuracy. Its the engineering challenge that CNC machine manufacturers have to deal with and also why there are so many different models of commercial cnc machines, it is not a one size fits all situation.

      While i agree with you when considering home cnc routers being driven by the smaller stepper motors, once you start to scale up in the size of cnc machine your argument makes no sense as alot of those machines have been designed for high speed machining recently. Features like through spindle coolant and closed loop spindle feedback allow some of the newer machines (in the last 10 years atleast) to achieve some pretty highspeeds as well as on the fly adjustments of speeds and feeds based on cutter load.

    2. Exactly this. The “brilliant idea” of a combined machine comes up so often it’s not funny. The reason you don’t really see them is because it’s a great way to make a machine that’s bad at everything.

      1. see comment above yours for professional machines that combine both with out sacrificing cnc capabilities

        It depends on what you are talking about, using a cnc machine to print plastic is kind of ridiculous i would agree, but add a MIG attachment on a cnc machine and you may have something that is better especially when you do not change the parameters of the cnc part of the machine.

        As a hobbyist machine you are on the money about it being bad, but the professional machines are making some great headways

    3. I have a cnc mill (bridgeport interact), and I have a e3d diamond mounted in a iso30 toolhead for it, also I’m just cutting the bracket to carry a small laser for marking purposes. I already do engraving with a second spindle using a bracket so will use the same principles of adding it to the tool carousel in linuxcnc. Theyre just tools to pick up in the manual toolchanger. Since I have a qc30 spindle, I can’t use a automated toolchanger anyway.
      I also have a 3d printer (printrbot), and I would print 99% of things using the printrbot. But, very very rarely, I need something thats outside its work envelope and I cant think of a way to neatly print it in sections, so using the print head on the cnc mill makes sense. I already have that capacity in my (home) shop, pretty much sitting idle 99% of the time.
      Yes, the mill as a 3d printer is terrible, its slow, it cant throw the table round quickly like a printrbot can and its a waste of machine and its a faff putting a heated bed on the table with isolation and stuff. But its free capacity.

      To the original post. Hey new, never done, had to happen. Really? are you that detached? there were people doing this 5+ years ago on the printrbot forums that I knew of, let alone cnczone and others.

  5. “Spinthe” anyone? A reverse lathe – starts with a heated spindle, on which 3D print head deposits layers, to additively create rotational (axially symmetric in 3D) solids. Should be easier to make then x-y-z printers.

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