The Ripper: A Different Kind Of CNC Machine

Here’s an awesome CNC build that crosses a standard CNC router… with a CNC machine capable of milling metal with ease. Introducing The Ripper. No, not Jack.

[Maximilan Mali] has been reading Hack a Day since he was a kid. A few years ago, he saw a guide on a DIY CNC build which inspired him to start designing The Ripper at the young age of 16. He’s 19 now (studying mechatronics in Austria), and raised enough money last summer to finally build his first prototype. It cost approximately 4000€ to build, which is pennies compared to a commercial machine of this caliber.

The machine has a bed size of just over a meter squared, with a Z height of 225mm. It’s also rigid enough to slice through aluminum at 850mm/s with ease! Take a look at the following video — we’re very impressed. Our favorite part is when he shows off its accuracy and repeatability by plunging a tool towards the screen of his very own iPhone.

The best part? He’s documented the whole process in a very detailed build log. He’s also planning on making the 3D CAD model available for a marginal fee. 

45 thoughts on “The Ripper: A Different Kind Of CNC Machine

  1. 850mm/min not 850mm/s… If he built a CNC machine that could accurately & precisely mill aluminum at 850mm/s, he would be worth 1 million dollars… err…100…billion… dollars… At any rate, AWESOME build!!! Incredible job Maximilian!!

    1. 850mm/s sure would be! I was a bit let down when I saw the video and realized that was a typo.

      Still, it’s a good looking rig for being homebuilt. I sure would enjoy having a giant CNC mill for milling MDF with precision and speed. I could start selling custom loudspeakers…

      1. We have a mill at work that can do 850mm/s with ease. Of course it has a 33000 rpm spindle and 108HP!

        Nothing wrong with the machine but watching them chew through aluminum like that is almost painful.

        Routers are nice but I am not into the woodworking thing. A friend has a 4’z12′ one he is removing the gecko servo drives and mach and installing a kflop with the snapamp board. He has done a couple neat things with it.

        1. That is how I feel about these things. Sure if I had the budget I would have attempted to get something into outer space when I was 19 (I was into model rockets but lacked the funds to go much into high power territory).

          Really nothing impressive about people that have money doing things that require money. No average college student would dream of blowing that kind of cash on anything but a semester of tuition.

          1. Haven’t you heard? College is no longer relevant. I am sure he learned a whole lot more by building this machine than he ever would have at a year in college. And if I am the one hiring people, a piece of paper that says “graduated” pales in comparison to “I built this. Here is the video. I milled this cool widget for you on it, and here is my portfolio of design work that proves I am competent.”

      1. Hackaday was making the claim that 850mm/min was impressive. It is not. It does not matter who makes it, it is not. I am criticizing HAD who is clueless about CNC, not the builder.

        1. I’ll grant you that. Depth of cut, bit diameter, type of aluminum/material all affect cutting speed. Making any sort of feed rate claims in the HAD post was just silly/unnecessary, and perhaps uneducated on the subject. But watching the video gives a decent feel for what the machine is capable of.
          Given that this is a home built, not based on a kit, I would say the feed rates demonstrated are, perhaps not exceptional, but certainly ‘good enough’ for a non production environment.

    2. Nice machine for milling rc foam plane wings and other similar stuff out of foam and wood, but certainly not suitable for aluminium or even steel, nevertheless a nice machine and I would like one besides my Maho 700, for these purposes. Using an old computer with onboard parallel port instead of new computer with PCI-E parport would cut the cost by another 1000$

  2. He created a neat router but many times people forget that at times just because it looks great doesn’t mean it’s going to function as good as it looks. Perhaps he is just playing it safe and hasn’t felt inclined to use it to what it can actually do…

  3. As always, kudos to those that build their own work and get posted on HaD.
    However, the repeatablity comment causes me a bit of concern(?). I don’t imagine backlash on the Z axis being a major issue. I would be more impressed to see multiple X/Y moves with direction reversals and then a Z move to show off repeatability.
    I am sorry if this sounds trollish. I don’t mean it to be.

    1. CNC routers (and CNC machines in general, really) are almost always 0 backlash. And, unless they’re very worn, ballscrews (which is what I’m assuming he used) inherently have very high repeatability. Even my POS homebrew CNC router with acme screws will repeat with far greater accuracy than my dial indicator can…uh…indicate.

      1. Everything has backlash, just like everything flexes.

        What you’re describing isn’t a test of backlash. For his phone his machine could touch that screen all day. The backlash is when it goes back up, there will be a period where the screw turns but nothing happens – that’s backlash.

        To test backlash you start at a point, move, come back and the see how far your are out.

        Software backlash compensation works by deliberately overshooting the mark and moving back, the same way as manual tool operators take up the slop in their machines.

          1. I’ve got to call you out on two things.

            Firstly the difference between repeatability and backlash is very relevant for CNC. Basically one is about getting to exactly the same point from the same direction (easy). The other is about getting to exactly the same point from the other direction (harder).

            Secondly, glass isn’t a liquid. It’s a popular misconception about it being a liquid, but it’s an amorphous solid.

          1. They are driven by stepper motors, you could probably hold them with your bare hand without any injury, unlike say, a mid-sized lathe which will happily eat the T-shirt along with the careless operator :P

          2. AKA the A. We have a set of these motors on our mill (look a bit up for the link to first test move on youtube). These motors are very strong, it’s very hard to hold them back by hand.

  4. Thanks for yours opinions so far! Yes actually that demonstration with the iPhone doesn’t demonstrate anything… However I can say the steppers never notably lost a step, even when milling large PCBs at high feed rates. The aluminum milling demonstration was actually the very first part I milled with ripper, and I wanted to play safe first… (The best result I achieved so far is 1600mm/min with 0.3 cutting depth and a 2flute carbide 8mm endmill). Mainly this result depends on some resonance factors and the composition of the milled aluminum material. I will add pictures of other milled (large!) aluminium pieces on my website soon :)

    1. I highly reccommend adding compressed air or mist coolant to the setup when milling aluminum. Supposing your feeds and speeds are correct, this is the last major thing affecting the surface finish you’re getting. Hot tool / work = shitty finish. Also you probably already know this but, climb cut vs conventional cut will also improve finish.

    1. +1
      It even uses the same old mainstream cnc controller software that I have yet to understand, why people are actually paying money to use it. Even author in his blog admits that it has lots of bugs…
      I think that this machine is nice, but the only special thing about it is that it is built from steel plates, but the painting makes an impression that it is all aluminium.
      And what kind of forum is that anyway, where people are saying that [properly tightened] timing belts will introduce backlash and that they are useless in cnc machines (author mentions that in his blog)?

  5. Its form factor is pretty standard for a CNC router.

    It’s an interesting machine, but the superlatives by the builder and sites reporting on it are a bit much.

    I don’t know what’s going on with the vertical side pillars, I guess they need to look impressive.

    I’ll ditto that timing belts won’t introduce notable backlash. I had a CNC vertical mill that drove screws that way.

  6. Not a bad machine at all, good attention to detail and craftsmanship. I get the feeling that the write-up is a little over-done to draw people in but overall its really good inspiration for someone building their first or second machine. I think he has a lot of really good pictures for his build log and gives a fair bit of decent information on picking components when preparing for a new build.

  7. Great job! I’m looking forward to reading the build log. Your build looks pretty stout.

    I regularly use a Next Wave Automation HD Shark Pro. It is a good machine, but it is too flexible in the Y. A lot of gantry style machines suffer from excessive flexibility in the Y axis. The machine is also compromised by a proprietary controller.

    Some designs seem to go for too much gantry height, when they could instead provide the option to mount the spindle higher. Similarly, Instead of building the gantry higher, the option to make the floor lower might be a better approach.

    I’m trying to decide whether to keep making do with the Shark, or build a new machine. As the saying goes, do you want to build a machine, or make parts? Eventually I’ll lose access to this borrowed machine and building a replacement will become a necessity. Or, I’ll get sick of not being able to control my 4th axis directly.

  8. Why are the majority of CNC demo videos so sucky?

    Look, my new fancy CNC can make my initials in wood, it can make my initials in plastic, it can even make my initials in soft metal. Wait, there’s more, here it is making a hole – yes a hole. Woohoo.

    How about showing your fancy new machine actually doing something useful?

    //same with 3D printers – so very tired of seeing one more yoda bust//

    1. Thanks for your great contribution.

      It’s a really solid build, so you really can’t complain about that. So what to do? Oh yeah – complain about the video and what he’s machining. hough it was actually a good video, with good audio, in focus, with shots of the machines from various perspectives, showing many aspects, cutting various materials.. Hmm.

      The video actually showed some excellent performance machining aluminum. A lot of machines are limited to very light skim cuts of only .010-.020″. This machine does quite a bit better, it appears. But nevermind that, because it doesn’t suit your troll.

      1. I saw the video and it looked like that machine was doing aluminum skim cuts of about 0.02″ depth increments. That is a good start, testing out something new, you want to start less demanding and work your way up.

  9. As a CNC shop supervisor (Aerospace for Boeing and Air Bus) ….. You have really impressed me with your intuitive way of engineering…..I have read all of your post on several forums and the adventure that brought you to completing this project at such a young age. Very impressive. Don’t be disencouraged by jealous men 4-5 times your age trolling your hard work….they are only upset because I just got done putting it to their wives. Haters are going to hate no matter what you do. Don’t believe me… some weirdo actually get upset enough to waste time responding to that comment about his wife just having the time of her life…..knowing I’m a complete stranger who probably won’t even see his post….smh anyways…..start selling the plans for that machine….you will make enough for a new build in no time ;)

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