A CNC You Could Pop-Rivet Together

You have to be careful with CNC; it’s a slippery slope. You start off one day just trying out a 3D printer, and it’s not six months before you’re elbow deep in a discarded Xerox looking for stepper motors and precision rods. This is evident from [Dan] and his brother’s angle aluminum CNC build.

Five or six years ago they teamed up to build one of those MDF CNC routers. It was okay, but really only cut foam. So they moved on to a Rostock 3D printer. This worked much better, and for a few years it sated them. However, recently, they just weren’t getting what they needed from it. The 3D printer had taught them a lot of new things, 3D modeling, the ins of running a CNC, and a whole slew of making skills. They decided to tackle the CNC again.

The new design is simple and cheap. The frame is angle aluminum held together with screws. The motion components are all 3D printed. The spindle is just an import rotary tool. It’s a simple design, and it should serve them well for light, low precision cuts. We suspect that it’s not the last machine the pair will build. You can see it in action in the video after the break.

22 thoughts on “A CNC You Could Pop-Rivet Together

        1. Yep, that’s what I meant. I wrote “You build a CNC (less-than-sign)device(greater-than-sign).” and apparently that got filtered as being a markup tag or something. Yay.

          1. @RÖB – I’m more surprised to learn that HaD doesn’t automatically convert those characters and actually allows html in comments.

            This text might scroll from right to left

            This text might scroll from bottom to top

            This text might bounce

          2. Well one can’t allow HTML/JavaScript to be reproduced back from the database that contains the posts so that’s out for security reasons like Cross Site Scripting (XSS).

            The rest is just sloppy coding and it’s not by any means limited to HAD – this site is driven by WordPress and many other sites have the same issues.

            They try to deal with all the issues XSS, code injection, SQL injection, code execution – all at once and they don’t think it through. Instead they wildly use things like stripslashes() / striptags() / mysql_real_escape_string() instead of htmlentities() / htmlspecialchars() on the way into the database to prevent mysql injection and thereafter the original content is lost.

            The proper way to do this is to prevent sql injection on the way in and deal with the rest on the way out.

          3. Building just “a CNC” is actually something I’ve been thinking about a lot lately. I recently had to opportunity to take a part some discarded equipment that gave me enough motors, encoders, metal bar stock, rods, etc, to build multiple homebrew CNC machines. But I got to thinking that it would be cool to just build “a CNC” that could be adapted to be many different devices. Could I build something with an CNC X/Y/Z control but make it quickly adaptable from a CNC router to a CNC plotter, paper cutter, mill, 3D printer, etc.

            I suppose the standard response is that I will end up with a machine that does everything but does nothing well.

          4. Carl.
            You will most likely end up with a machine that does everything but does nothing well. However, you should still totally do it. It will be a great learning experience and it is very likely that it will be able to do it well enough for most practical purposes:)

          5. @[Carl Smith]

            It may well be better to make two machines due to costs.

            Costs –
            CNC Metal Router – large expensive linear rails / guides – expensive ballscrews – expensive steppers – expensive router tool – expensive frame – all because of the torque and rigidity required.

            CNC Wood Router – less rigidity required – smaller linear rods not much cheaper – threaded rod is ok and much cheaper – even belt driven is possible and is much much cheaper – cheaper routing tool – cheaper steppers as less torque required – cheaper frame.

            3D printer – hardly any load – fine to use cheep belts, cheaper small rails guides, motors, frame.

            LASER Cutter – practically no torque or rigidity required – cheapest stepper / belts / tool (LASER).

            You could have an all in one but the speed lost for 3D printing and cutting would be great – even painful.

            I think a mix of low power / torque CNC router for softer woods – belt driven – could be an all in one except metal routing. Metal routing is in a league of it’s own.

  1. LOL @ cloths peg spring to tension synchronous belt but hey it obviously works and the cost on BOM is low low low lol.

    Good build and it’s surprising that he can get enough torque from NEMA17’s at 15:4 reduction.

    But still all those 3D printed parts mean that it’s not a first machine.

  2. I was just wondering how “low precision” this build is.

    Assuming 1.8 degrees per step (worst case) then there would be 200 steps per rotation and then it is reduced by 15:4 and then to a 18 tooth output shaft to what looks like gt2 synchronous belt.

    So we have 18 teeth which is 36mm from 750 steps which is 0.048mm per step or 20.83 steps per mm. so it’s not too bad for just wood routing.

        1. I say yes to your answer, although we’re probably talking about different things, precision vs accuracy.
          I think what you mean is that the frame is less stiff and so would smooth out individual steps that you would otherwise see with a perfectly stiff frame.
          What I was talking about was more that when you’re moving the X or Y axis, the frame “lags behind”, which means that you’re not actually on the position the sensors tell you.

    1. It happened to me too. I recently came into possession of the guts of a couple Imagesetters. Machines that used to be used in the printing industry to print images of newspaper pages onto film, the film then being used to expose the coating on the printing press plates. Unfortunately (or maybe fortunately) didn’t have a pickup to haul the machines home intact so I quickly (well, many hours over several days after work) pulled them apart and took home the internal assemblies in the biggest chunks I could carry and put in my SUV. I’ve spent the last month off and on taking the assemblies apart. I have a couple dozen DC gear motors, a huge pile of shiny long rods, a 5 gallon pail of rollers, a big stack of nice aluminum bars of various sizes, countless bearings and bushings and little locking collar things I’m not sure what are called, dozens of micro switches and optical interrupter switches, power supplies, and numerous other stuff I can’t remember at the moment. And also a lot of aluminum plates of odd shapes I can’t use and will haul to scrap. And I’m not done taking it all apart yet. I have taken a lot of video and pictures but haven’t got around to making a blog post or YouTube video about it yet…

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.