Sub $300 CNC, If You Have A 3d Printer

[Allted] has designed a CNC machine that you can print yourself; adding conduit, bearings, and the standard vitamins to bring it to life. The CNC machine uses a mechanical design similar to an etch-a-sketch, though instead of the maze of pulleys and cable it uses four stepper motors to do the X and Y translation. The machine looks to be about as accurate as a Shapeoko, and is able to handle light cutting in aluminum.

The coolest part is the extensibility of the printer. For example, [Allted] needed to print a lot of parts to make orders of the kit. So, he built a 4 headed 3D printer by copying blocks of the design, and tying them all to the same belt. The design also seems to be a little more resistant to dust and debris than some homemade rigs. The CNC won the Boca Bearings design competition. If you’d like to build one yourself, [Allted] has all the instructions with print setting recommendations on his website.

37 thoughts on “Sub $300 CNC, If You Have A 3d Printer

  1. I have just finished up mine, use with end mills to do wood carving, just got my engraving bits so going to try that next.
    plan to use it to make pancaks.
    seem to be getting +- .05mm in the z and +- .04mm in the xy
    my build volume is 400x900x300mm
    This is an grate CNC if you do not need super fine restoration.
    some fun bits, need ~ 2kg of filament, and printing takes ~130 hrs. it took over a week of contuses printing to get all the parts.

    1. I also built the MPCNC. I made mine a similar size. I wanted something that could eventually allow me to build my own guitar from scratch and that could do aluminum and pcb milling. I think my build volume is about 600x900x150mm. The printing was a serious pain in the ass as all of my PLA had swollen from improper storage (doh!). Bought a bunch of ABS and finished it off. Best part of it is the price. I probably spent around $400 total after upgrading a few things from the hardware kit and splurging on a better spindle than what was recommended. I hope to eventually build a laser end for it as well. Would be nice to have something that can double as a CNC mill and a laser cutter without much fuss. I’m currently working on getting an auto home/leveler installed. It would be so nice not to have to manually home and level it.

    1. dirty sla looks like it would be $1500 from there website, .95 cents a gram. you can buy the printed parts off his website for $190, probably cheaper than shapeways. check out his store

          1. Yep, I printed them for a friend who wanted them. If you look at (, one of the pictures is this CNC. $80 was a “friend deal”, I’m not sure what my 3d hubs would say. What I’ll do is keep the $80 + shipping price for the next say, 10, people who show up in my Queue, then move to the $100-$120 range. I don’t know, I may just keep it at $80. I don’t really care honestly.

            I’m somewhat useful because I don’t particularly care about the money, and my printers didn’t cost anything. The only reason I even care to charge is to support my project, BotQueue. I also will allow you to select from colors I don’t have if you’re willing to wait a little bit longer and pay $10 for each Kg that would need to be bought.

            The parts for this project don’t even need to be super accurate. You can get away with .4mm layer height I think. I printed these at .25mm.

          2. @allted, sure will do. ABS does shrink a little bit, so the parts do require some sanding to have the conduits fit. Also, applying too much pressure can cause the pieces to crack. Are those the reasons for your suggestions?

            Thank you for making such a great design! I just want more people to have access to printers and CNCs, and I know some people aren’t going to be able to do the higher price. Still, always support the author when you can!

          3. Please only use PLA, maybe PET. Very few people have much success with ABS it messes with the center assembly dimensions causes weird issues.

            I’m doing my best to offer great prices but man 130 hours of printing and almost 2 spools of filament, $80 is awesome. Hats of to you!

          4. Sure, I’ll throw up one of my printers that does PLA on there tonight. I think it does .2mm layer heights by default. The Mini can use PET as well, but I don’t like using PET on it because it REALLY sticks to the bed.

            And like I said, the only reason I can offer that price is because I use BotQueue to control the printer, and because I don’t really have to worry about the cost of my printers. I also get a discount on the plastic, so all of that allows me to be fairly cheap if I need to.

            Have you done a build in PET or HIPS? Would you like to coordinate a build for that? I should be able to do PET reliably, and I know I can do HIPS, but I also don’t know if the supplier that if the supplier for my ABS/PLA has those filaments.

          5. Not really, I Like using PLA because it usually works right the first time. At my last job we used PET mostly, it could handle heat and humidity well so we used it for silicone drying fixtures in a low temp oven.

            I don’t use PET in the kits for sale because I can’t find a good price for it.

            Nothing should need to be changed to do a HIPS build, but I have zero experience with that.

  2. There is the Cyclone CNC as a mostly 3D printed mini CNC option too. I was considering building one for PCB milling/drilling at first, but quickly realized that with the printed transmission gears, off the shelf threaded rods and all these cost cutting measures, it would not really work anywhere near the precision i am looking for. So, i’m now building my own frame with standard aluminium extrusions, precision linear bearing rails and a precision threaded rod for the z-axis. X and Y axis are going to be belt driven for now, as it should be strong enough since i’m not planning on having massive loads/accelerations on these axis anyway.

  3. Is there a thing the other way round? I do have a cnc-mill, I want a 3D-Printer! But all of them have 3D-printed parts, which I think is stupid, because they are not rigid enough. And those terriblw threaded rods as a frame! Urgh. Isn’t there a nice open source millable 3D-Printer with joints milled from aluminum?

    1. Have you tried using any of those printers using 3D printed parts? I have had mine for a few years now and would prefer to use it any day before any fully assembled printer, makerbot, that costs you an arm and a leg. I have seen equal and often times much better print quality than some makerbot printers which costs a few grand.

    2. LOL odd request.
      I mean seriously: Just make one – design it to what ever strong rods you can find on the junk…
      Most of it are linear rails and other parts you order anyway.
      The reason why 3D printers are so flimsy: There are no really strong forces involved.

    1. I hope so, as soon as it stops raining I will be trying that out. I don’t see any reason it would not. To trigger it I will start with a manual trigger and if things go well I will automate it. Should be easy, I’ll use a SSR if it is needed, depending on the switch voltage.

        1. Another user told me I should be able to wire it to the ramps directly depending on the plasma itself. He said the switch is just to wires that plug in to the front panel easy to unplug and run our own. I will probably use a SSR just to isolate things as much as possible, and it is cheap insurance that I already have laying around from another project.

      1. I figured out that there are two parts associated with the tool holder that are too big to print. I’m going to try printing the c_xy part as 3pieces. There is another piece that I’m going to split as well, dont recall the name.

  4. My question is relative to the electronics, wiring, and software. I can build the parts easily enough and make everything work mechanically. I can follow the wiring diagrams, also. I get nervous thinking about connecting it to the software, flashing things, etc. Is the support reasonably reliable in helping you get the unit off the ground once it’s built?

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