Settling the Debate – CNC vs 3DP

Now that 3D printers have emerged as the tool-of-choice for many makers and educators, there seems to be a line drawn in the sand between CNC and additive manufacturing. Many manufacturers even worry that 3D printing may one day replace traditional manufacturing in the form of at-home production (perhaps sooner than we think).

While these concerns are somewhat legitimized by a quickly emerging market for 3D printing, the gap between printed parts and components that are truly usable is still massive. Some would argue that the biggest hindrance to at-home manufacturing is simply cost (which is quickly diminishing), but as most CNC users would agree, it is much more than that.

The rhetoric in the 3D printing versus CNC debate is often centered on quality and cost, but this is where machines like Tormach’s PCNC 1100, PCNC 770, 15L Slant-PRO, PSG 612, carve their place into the marketplace. 3D printers, like the MakerBot, Lulzbot, and Form1, are fairly inexpensive ($3,800, $2,200, and $3,300, respectively), but many users don’t have a full comprehension of a 3D printer’s capabilities. Printers that are capable of the fantastic imagery that is touted in the marketing campaigns can cost upwards of $15,000 to $750,000, or more. 3D printers are certainly capable of great things (including metal component production), but not on a budget – direct metal laser sintering (DMLS) machines can cost upwards of $1M. While the newfound fanfare for this technology is helping it progress, we are far from being able to produce metal components in non-industrial environments, unless it’s being done on a Tormach PCNC or similar.

Tormach has etched out a unique place in the market of CNC mills, lathes, and cutting machines because the gap between professional and consumer is being bridged. Prosumer is the new emerging term. While this buzzword may often be a trigger-happy description for marketers, here at Tormach, we consider this term essential.

3D printing is certainly buzzworthy (we even have a couple in our office), but there is still an important gap between CNC and 3D printing. This gap shouldn’t be so much a line in the sand, but rather, a partnership of the right tools for each user. Both machines are capable of intruding on the other’s place in the market, but where each thrives at affordable prices is important to consider.

CNC mills are ideal for projects that require high-precision and ready-to-use materials, whereas 3D printers are better for conceptual prototypes and visual justifications. Both types of machines can be used within these arenas, but they vary greatly in efficiency and quality.

What the CNC versus 3D printing debate boils down to is the weighing of capability and quality against price and efficiency – the rubber hits the road in a debate about budget and need. With an unlimited budget, I’d have both a million dollar stereolithography printer and an industrial CNC mill with all the bells and whistles (i.e. an array of tools, a fourth axis, etc.), but it’s an exciting time to be an engineer right now in that I can have a PCNC 1100 and a Form 1 printer in my garage for less than $20k and accomplish many of the same things. CNCs and 3D printers both have their place, and as the market continues to adapt to an ever-changing world, these machines each have their place, side by side.

Chris Fox

Chris comes from a publishing background with years of experience in science, technology, and engineering publications. Previously an editor with Product Design and Development and Gizmag, he has a keen eye on the maker community and the changing landscape of the world of prototyping, product development, and small-scale manufacturing. Chris has been working with clients to create Tormach's customer success stories since 2013. Follow him on Twitter @TheChris_Fox

Chris Fox

8 thoughts on “Settling the Debate – CNC vs 3DP

  • Avatar
    03/13/2015 at 10:36 am
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    3D printing is cool, but I think there is no way it will ever take over in the home machinist/maker market just because it is so SLOW.

    Yes, it will do things that aren’t practical on a milling machine, but as I said, it will do it very SLOWLY.

  • Avatar
    03/13/2015 at 11:41 am
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    The answer is easy. Everybody needs both. Which would you rather give up, your right hand or your left hand?

  • Avatar
    03/13/2015 at 1:26 pm
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    I think the 3D printing movement is being limited by lack of exposure and imagination. I am a manufacturing engineer and I have access to an FDM printer that prints in ABS plastic. Most of the engineers at our company use it for prototyping and I do as well, but I also print a lot of final use parts for everyday use, brackets, custom equipment mounts, tools, etc. People are often shocked to find that I am printing items and taking them to the production floor to use right away. ABS is strong and today’s printers can print excellent quality parts that work in the everyday world. Once people start to grasp that notion, the 3D printer market is going to be huge. We’ve only scratched the surface of the potential so far. I recently had some parts printed on a $2500 Ultimaker 2 just to compare to our $50,000 machine at work and there was very little difference in the print quality. Soon, I think everyone will have a 3D printer in their office or shop. There will probably always be a need for milling machines and lathes for precision components, but the gap is getting smaller and smaller. I think a huge opportunity exists for a company like Tormach that can put in the R&D time and emerge with a quality product in that I think the way of the future is going to be dual purpose machines. We are already using lathes that have dual spindles and live tooling for machining on turned parts while they are still in the lathe chuck and they seem to be great machines that are loved wherever they have been implemented. I think a machine similar to the PCNC1100 that could 3D print a part in ABS or Nylon and then turn right around and machine precision features into that same part without removing it from the table would find huge acceptance in the industrial world as well as the hobby/maker garages. I don’t think speed is nearly as big an issue as some believe it to be. At work, I 3D print items and have parts on the production floor within 24 to 48 hours whereas if I had to have those parts machined I would have to make drawings, send those out to be quoted by three sources, pass that along to management for approval who then passes it along to procurement to obtain a P.O. and then you wait a week to 10 days to get the parts back. Even if you have someone on staff that can make the parts, they generally need a drawing and the parts need to be CAM’d and machined which is probably going to be a 24 hour turnaround at best because those people are generally tied up making parts for lots of different projects. Personally, I am excited and can’t wait to see what the future holds because I believe we are going to greatly expand the capabilities of the “little guys” among us.

  • Avatar
    03/13/2015 at 3:01 pm
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    I bought a Zortrax 3D printer nearly a year ago and think that Chris really nailed it – 3D printing makes a good supplement to CNC machine tools for many needs.

    A 3D printer will make 1x2x3 block a lot more slowly and less accurately than a CNC mill, but it can make a model of something like a Star Wars light saber much faster and with far less programming effort.

  • Avatar
    03/16/2015 at 8:03 am
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    I built my 3D printer using my PCNC1100 and a laser engraver. The printer works very well and I was able to create a bunch of parts on it. As stated earlier, they are kind of slow while printing, but the CAMing is SUPER-FAST! Regardless, to me the printer is kind of useless as the stuff that I mostly build is better done in metal and has little 3D features.

    There will be places were both are needed and there will be places were only one of them is needed. The beauty is that with a CNC mill you can EASILY make your own 3D printer. But with a 3D printer it will be VERY HARD to make a CNC mill. Just saying…

  • Avatar
    03/19/2015 at 2:23 pm
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    Anyone who thinks that 3DP will supplant CNC, or who thinks that 3DP will revolutionize manufacturing has never used either.

    The missing perspective is material science. 3D printers require parts be made of materials that can work with the 3DP process. Most real-world applications require much more than that the material simply be the intended shape: they need to bear loads, to avoid cracking, to be cleanable etc – a lot of things you just cannot get with printed plastic parts.

    I use both machines – and use them for different things. But more often than not – if I am making something that I need to use in the real world – something beyond just making a model of what a future product might look like… I use the tormach.

    Best example… The “printable” 3-D printer project (RepRap) that started the home 3d printer movement – ends up making HORRIBLE 3d printers. I started with a rep-rap, and slowly replaced all of the 3-d printed parts with aluminum or acrylic parts that I made on my Tormach.

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  • Avatar
    10/19/2015 at 8:54 am
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    At Tosa Tool we have both machines. The 3d printer is very useful and fairly effortless. PLA and ABS are very useful materials and you can change settings to adjust how strong and durable they are (layers and fill %). We often work with our customers with the 3d printer until they are certain of what they want and then machine it on the PCNC.

    When sintered metals and plastic metal matrixes are proved out 3d printing will become more useful, and very possibly replace machining in many applications.

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