Freakin’ Huge CNC Router

[Tom] sent in a gigantic 3-axis router that he pieced together during a 2 week-long work experience placement. Looking at this picture showing a 12-inch ruler on the work area, we realized that this may be the largest CNC router we’ve seen on Hack A Day.

[Tom]’s employer gave him some obsolete axes, so piecing the mechanical components together was very easy. The only real problem was interfacing the CNC controller to a computer. This meant [Tom] had to convert G Code to the code used by the antiquated NSK axes. Where G Code defines arcs with a start point, end point, and radius, the NSK code defines arcs with a start point, end point, and another point along the arc. It’s a tricky bit of math, but [Tom] built some software that did this in Visual Basic.

Right now, [Tom] only has a pen tool attached to the router; you can check that in action after the break. We’re trying to imagine what we would do with a 4 m² work area; this could easily be used to make a giant reprap or other 3D printer.


22 thoughts on “Freakin’ Huge CNC Router

  1. Nice writeup and device but are we sure that’s called a ‘router’? Isn’t there a separate name for something that cuts like that? Since it’s more a cutting plotter than a router really right?

  2. “this could easily be used to make a giant reprap”

    hey, i thought those just could make themselves. thats the point right?
    either that or perhaps like ‘green’, or ‘open source’, ‘self-replicating’ is simply a handy but entirely empty marketing term that actually means the opposite of what it used to.

  3. Neat. But not that massive. A friend of mine has a CNC router about the same width but 24 feet long.

    One thing I noticed about this is there is significant dwell time at the end of each move. This might cause problems. These slide were intended to be use for repetitive tasks like moving parts from one place to another where that would have not mattered.

  4. Uh… 8’x4′ routers are the norm for DIY cnc. In fact, the first link on google for “DIY cnc” is a 8×4′ router ( ).

    I’m getting dangerously close to rant territory, but for the cost of any of the toy 3d printers currently availabilities you could build a much larger three axis mill or router (or even laser) that is infinitely faster, more precise and more useful.

    Just thought you should know.

    1. Every time I see this statement made it turns out there are hundreds of dollars of bearings, electronics, linear movement hardware, motors, etc that just happened to be ‘spare’ or ‘from a friend’ or a one off ebay listing, or from a dozen suppliers with the actual cost double that shown because somehow freight doesn’t count.
      Don’t forget all the other bits you’ll just be able to knock up in your fully equipped workshop…

      I’m not saying it can’t be done, people manage it, but not nearly as reliably as you can order one of the ‘toy’ kits.

      unless you care to share.

    2. Thank you. This also bothered me. A router that takes a 1-1/4 HP router and a 4×8 sheet of plywood is not only pretty normal, its often cheaper than these toy printers, on top of being far more capable in material, scale, and in accuracy.

      They would also more ‘self-replicating’ as well (whatever that actually means by ‘cult of reprap’ standards). At any rate, far more so than those little extruders will ever be.

    3. “Useful” is entirely dependent on what you’re goals are and not some intrinsic property.

      Unless I missed the memo and DIY 3 axis CNC’s can do something like this easily:

      Sorry but CNC’s primary domain is planar material. Sure you can flat-pack style make a 3d object but those “toy” 3d printers have their purpose too.

      1. Remember that it’s trivial to put an extruder head (and simply Z axis) on a CNC router, but almost impossible to put a cutting head on a RepRap/Makerbot (and not have the thing wobble all over the place due to totally inadequate stiffness, if not collapsing under the weight of a router).

      2. Possibly, but all things being equal you’d need to build some enclosure to keep the temperature up, a heated build platform to keep your layer heating even and other little things like that to get a good build.

        Assuming that the person would even want a CNC to begin with. I just don’t see the point of snarky fanisms. Why can’t people just enjoy what they have or be allowed to not have exactly the same interests or goals as other people.

      3. Also, I think there’s some vague homeowners privilege when it comes to CNC builds.

        I don’t live in a house, I don’t have a garage, I don’t live near anyone who does have one and I can’t just go out and build a workshack.

        I live in an apartment, a tiny apartment next to other apartments. I don’t have room for a 4×8 CNC machine but I do have room for a desktop 3d printer.

  5. 22 years ago an engineer in Longmont Colorado built a 4×8′ CNC router from a discarded 9-track tape library. It’s nice to see hardware hacking has progressed astronomically in the interim.

  6. For my first job after finishing Uni (mid 1980s), I was repairing Gerber CNC garment cutting machines. These had a table about 30′ x 10′ which would hold down up to 50-60 layers of cloth using a vacuum. The head of the machine was a (very sharp) oscillating knife controlled by an HP 2100 mini computer. The patterns for the fabrics were designed on a light-pen driven Imlac vector graphics workstation which was completely implemented (I think) in TTL logic.

  7. We have a very large 5-axis CNC Mill at the shop where I work; the work envelope is somewhere around 10ft in the X, 20ft in the Y, and 10ft in the Z. The gantry was built by a company called PAR systems, while the CNC bits are all from FANUC. We use it to mill down successive sheets of 3inch MDF for use in fiberglass mold-making. It’s also handy for cutting large batches of parts out of redboard or foam sheet, or anything you can manage to screw down to the table, really. The operator’s work bench is literally inside the work envelope, so that can be a little un-nerving the first few times you use it. :P

  8. “Where G Code defines arcs with a start point, end point, and radius, the NSK code defines arcs with a start point, end point, and another point along the arc. It’s a tricky bit of math…”

    I know I’m nitpicking… but what exactly is tricky about that math? It seems very straightforward.

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