Desktop Mill Built As A High School Project

This desktop mill would be impressive coming from anyone, but we’re really excited that it was made as a high school project. [Praneet Narayan] built it during his design and technology class. As his build log shows, he worked with a range of different tools to make sure he had a rock-solid platform on which to mount the motors and cutting head.

The uprights of the frame are made from two steel plates. After hacking them to rough shape with a plasma cutter he finished the edges with a mill. The two parts were then tack welded together so that the mounting holes could be drilled in one step, ensuring alignment between the two sides. The rest of the frame parts are built from extruded rails but he did machine a set of mounting plates to pull it all together. You can see the finished machine milling a message in MDF in the clip after the break.

[Thanks Kevin]

43 thoughts on “Desktop Mill Built As A High School Project

  1. Impressive build no doubt. I’m wondering though what the benefit is of having the table act as the Y-axis instead of the arm. I mean yes it works either way no doubt, but was it just easier to do in a DIY application such as this? Just wondering.

    1. everything is a compromise, if the part you work on are light it might be easier to move the table and part instead of a heavy tall gantry and it is simple to fit the drive on center. if you make a moving gantry you need to have either have dual drive or something under table. If your part is heavy it might be the gantry that is easiest to move and for a large working area the over all machine could be made smaller.

    2. The reason to make the Y-axis work like that is with a very slightly modification you can work on very long pieces of wood, to use it, for example, to carve a sign. I had a Carvewright unit that worked similarly.

      1. ? I’d say it is the other way around, with a moving table the part is moving so it is really hard to work on something bigger than the machines area.
        and at some point it will be too heavy for the machine to move.
        With a moving gantry the part is stationary so you mill one part move and index as long as you need

    3. I did go with the moving table design as the weight on the table will be far less than the weight of the gantry. Obviously this type of machine is only really a good design in a smaller cut area and as the size increases it seems more efficient to move the gantry than the table.

      Another key aspect of this design is that it is far more rigid than a moving gantry and this will be important when milling traces in PCB’s.

      1. You’re spot on. Rigidity and alignment is harder to achieve on a moving gantry than it is on a moving table. I built a moving-table mill for the same reason.

        Also, parts count is less on a moving-table. You typically want 2 leadscrews on a moving-gantry style mill.

    1. But the mill wasn’t critical to make the basic machine though. The mill use here was for visual aesthetics. Surely Praneet, was to be graded on this project, so was a good idea to use every tool at his disposal to make it looks as good as it works. A hacker not limited to classroom time available should use other methods to clean up the plasma cut edge if they desire to do so A practice hand with a plasma cutter my have left a cut that many hackers would be fine with. Students are taught to design, construct products to satisfy paying customers I believe.

    2. Using a mill really isn’t necessary. You could easily replace the steel plates with other alternatives such as thick aluminium extruded rails. I designed the machine around the tools and machinery I had access to. I just thought it would be a shame not to use the mill if I can.

    1. the cost is about three days.

      that’s the amount of time it took me to chain drill and hand file similar mounts from 1/2″ billet for my high school metal work project.

      Hence, the mill wins every time.

      still doesn’t take a mill to build a mill!

      1. Praneet,

        When I saw the link on Reddit, I had to submit it here. Congratulations on the build and just keep following through with your projects. My personal weakness is getting lost in the details and completing anything. It’s fun, but I expend huge amounts of energy with no tangible results (other than the fun, that is).

        If you merge the passion of an amateur with professionalism, you’re sure to far… and have a blast doing it.

        Thanks,

        Kevin

    1. Steppers: cheaper, more low speed torque, simpler control

      Servos: feedback, high speed

      For a low speed (milling machine) DIY application, steppers win hands down. You don’t lose steps unless you have your acceleration and velocity set too high or if you crash. Even a moderate sized stepper mounted to a leadscrew will generate more than enough torque so losing steps should never be an issue.

  2. A great build and more impressive by the age of the builder. Moving the table in this kind of machine allows it to be more rigid. If the all 3 axis are part of the same movement than you combine the deviations. So if the x axis flexes it will also throw off the y and z. The trade off is that the machine has a larger footprint when you move the bed.

    Josh

    1. I noticed the tile as well.

      I just can’t congratulate a kid (over and above what I would do for an adult) on building something when he has access to a plasma cutter and a mill.

      Fantastic to be sure, but how is this more impressive than some less privileged kid doing something mundane like rebuilding his transmission?

      1. Not jealousy,
        Just a statement good tools and good skill lead to good work.

        Skill is age independant of age.
        The premis if the content is. If you have access to the tooling that this guy did then professional results are an expectation not a bonus.

        The build it really (really) slick. It is impressive. But given the tooling that he has access to it would be disappointing if it looked rough.

  3. Fluffles,
    At that age any initiative more than chasing girls should be applauded.

    And this is more impressive because he designed it (I think).. the scale of building something like this from a mental standpoint is much more challenging than rebuilding a transmission. (I’ve done both)

  4. Very impressive. As a 16 year old, even more so. Hats off to you. Many adults couldn’t do it.

    Sorry to read some of the cranky responses. Open controller or not, it’s a great first experience and the results speak for themselves.

    You will go far young man.

  5. Sweeeet! I’m a few months into my first CNC build and this is inspirational… Nice job! I like how you turned your own shaft collars – I recently had to have some right now, though mine are kind of clunky-looking because I used a drill press and a hole saw instead of a lathe, lol.

  6. ONe thing for sure,the build is quite impressive.

    but hard to believe build by 12 Std. guy.
    if you observe closely,the machining methods,the way he made the dimensional markings are quite professional.and being a mechanical engineer,(i have build several routers) i know the expertise you need to have during the squareness alignments and bearing arrangements.
    he might have a guide to help him.

    but above all this,its quite impressive job.

  7. Hi nice build.
    I have built a CNC mill and have tested it out running on 12 volt gel cell batteries.It does not seems to have enough power to run the motors. Would you share your power supply circuit with me? I have no idea of the power requirements for the stepper motors i bought on ebay. They have no markings and can not find any information. They are about 3inches in diameter. and look the part for the job.
    Thanks in advance.
    Colin

    1. Hey Colin,

      The power supply i used was a 48V switching unit. For the controller i also used a Gecko G540 which is basicly one of the best diy controller solutions on the market. It’s pricey but is just a breeze to setup and it just works!

      Praneet

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