ShapeOko build log — it’s a CNC mill in a box

shapeoko-build-log

We’re not blatantly trying to promo this product. It’s just that the build log covering a ShapeOko assembly process taken on by [Anool] is like crack for those of us who have yet to acquire our own desktop CNC mills.

Like the title says, this thing is basically a mill in a box. But [Anool] decided to order the version of the kit that doesn’t come with any motors or control electronics. He also planned for future upgrades by ordering additional extruded rail to increase the size of the ShapeOko. After assembling the frame his decision to source stepper motors locally bit him as they were out of stock. But there was still plenty to do preparing control electronics during the wait. He based his system on a Raspberry Pi which talks to an Arduino to address the motors and monitor the sensors.

Once all the parts were finally accounted for he tested the rig as a pen plotter. The pen was eventually replaced with the router motor and that ring light PCB seen above was the first thing he milled with it.

[Thanks Justin]

Comments

  1. Phil says:

    I’d class it as a CNC router. There’s nowhere near enough stability in that design to be classed as a mill.

    • joejoedancer says:

      Thank you! I get excited when I see “Mill” because I think metal cutting on the cheap. Then I get :( and realized these things can barely mill wood.

      • dext0rb says:

        They mill wood quite fine, I think. Check out some videos on Youtube. Some people are also doing work on aluminum. I’m building a ShapeOko now with extensive modifications, hoping to mill aluminum eventually.

      • macona says:

        Especially with that POS “Spindle” the chinese are selling. Its just a generic DC motor with a ER collet chuck on it. An accurate spindle this does not make.

        • Joe says:

          How is a spindle “accurate”? I am building a CNC and have to pick a router or spindle. Please explain.

          • Bill says:

            An accurate spindle will put the tool as close to the exact center of rotation as possible as well as minimizing bending due to side forces.

          • macona says:

            Spindle design is pretty complex. With this thing you have two bushings, if you are lucky radial ball bearings. You will run into multiple problems. First you will have runout both axial and radial. Assuming that thing actually has ball bearings they are designed for almost 100% radial load and almost nothing in the axial direction. You will have free play axially because of this and since cutters have forces in this direction you will have problems. Plus cheap bearings will have radial runout as well, this causes oversized cuts, poor surface finish, and short tool life.

            Proper spindles will have a bearing configuration that will support the shaft in both axis. This can be done with standard radial bearings and thrust bearings, tapered bushings, tapered roller bearings, or angular contact bearings. On smaller spindles of any decent quality you will find they have angular contact bearings. This is what you want to look for. If it does not have AC bearings or the bearings stated above dont buy it.

            Dont buy a hand held router for a spindle on a cnc machine. They are noisy, run hot, and suck the chips and dust through the motor, especially if the machine is in an enclosure. Look at the cheap chinese three phase spindles with ER collets. You can get them from 800w (1HP) to 2.2kw (3HP) for pretty darn cheap and from all accounts they are pretty good spindles. They are no Colombo, but they dont cost $3k on up. You will need a VFD to drive them which means you will need 240v. These motors are small enough where you can use a 120 to 240 transformer to get the voltage. Leeson does make a 120v in 240v out 1HP vfd that would be fine for the 800w spindle.

            Another option is the spindles made by Fischer Precise (Formerly Precise). They are very, very high quality spindles. The older versions were brushed motors and the newest ones are brushless. They usually have ABEC 7 or 9 bearings. There are usually a few on ebay.

            FWIW, I work on CNC equipment for a living. Our newest 5 axis CNC mill at work has a 108HP, 33000 RPM spindle that costs $70k alone!

        • Rogan Dawes says:

          Any suggestions on where to get a decent spindle?

          • Anool says:

            I’m looking at routers from DeWalt, Dremel and Black+Decker. The ShapeOko forum has lots of discussion on Routers, Spindles and such.

          • Phil says:

            Do a search for 2.2kw watercooled spindle on ebay. They are quality spindles but I dont think that machine will lift it. I doubt your depth of cut will be able to exceed 0.4mm per pass for a decent finish.

            What thickness plate is this using for the gantry sides/z axis plate. It looks about 6mm, I wouldn’t use less than 18mm. This should make a decent engraver though.

          • macona says:

            It depends on what you want to do. For wood and aluminum look at the air or water cooled 3 phase spindles. From all accounts they are pretty darn good for the price. You will need a VFD to drive it. For aluminum you must have coolant. This ensures the aluminum does not build up on the bit. I use micro drop coolant and it works great with minimal mess.

            For steel, well… , buy a real mill!

  2. Will Lyon says:

    Pi talking to an Arduino? Why not just use one of the other? There’s plenty of Arduino-based CNC control devices out there.

  3. david says:

    these are sweet, but if you want to cut metal, check out a tormach. loving mine.

    • macona says:

      Or if you have the room just buy a used VMC or HMC. You will be way happier and come in at half to two thirds the cost of a Tormach and have a real control on it.

      • Sansbury says:

        I spent the last couple months searching for the legendary “good VMC for the price of a Tormach” and to make a long story short, I took delivery of a PCNC 1100 yesterday. For about $12k delivered I got a brand-new machine with a 4th axis, touch probe, and a number to call and say “send me replacement parts!” if anything breaks for a while.

        The closest I came to a deal was a 20-year-old Kitamura that was 5 miles away for ~$6k. It was running but the Z-axis would occasionally fault and the owner needed space for a new machine. By the time I was done with riggers and running 3-phase power I was looking at another few thousand dollars just to play “Let’s see how long it runs!” And it wasn’t set up for a 4th or touch probe, nor were any of the lower-priced machines I saw. After a few years with EMC2, I’m not sure what a “real control” would get me other than a lot of hair pulling if-slash-when a board gives up the ghost. If anything, I prefer the very clear and open hackability of LinuxCNC even if it lacks many of the commercial refinements.

        All that said, there’s no question that it’s not going to move metal half as well as a 20-year-old Fadal. I talked to a bunch of owners about what they did with their machines and the ones who were doing things similar to what I want to do were satisfied. The ones who tried to run production discovered every limitation. When the dust settled, the benefits outweighed the limitations for my anticipated uses. We’ll see where I am a year from now.

        • macona says:

          We sold a nice Kuraki 700 for about 10k just recently with 4th axis to make room for a new machine. Real nice machine.

          Was the machine a Mycenter? They are good machines. Probably a bad encoder cable. The thing about having a real control, in the case of that machine probably a Fanuc 0m, parts are available. It is pretty easy to ID the part and there are many places where you can get rebuilt units and there is always ebay. Almost every machine at work has a fanuc control on it and the problems are rare and when there is something bad it is easy to get parts.

          • The Snob says:

            Yeah, it was a MyCenter. I think you told me I should buy it when I posted about it over on HSM and you were probably right. It came with enough tooling that I could have ebayed it, scrapped the machine, and at least broken even had it been a dud. Of course, deals like that don’t last long and by the time I got there it was gone. Us mere mortals don’t know that wonky Z-axises on Kitamura MyCenters are usually just bad cables, so by the time we can get feedback from our wise elders, the deals are gone. Also, in about three months of watching CL, eBay, and calling dealers, that was by far the best deal I saw.

            If things go well and I need to start making parts in any real quantity I will be looking for a Fadal or maybe a late-model Haas if I feel like taking out a note. As it is though the material removal rates on the Tormach seem fine for me. I’ve almost gotten by using a homebuilt mini-mill conversion, and I mostly wanted something a bit bigger and that didn’t require constant fiddling to keep it going. The Tormach 1100 is a lot bigger but I didn’t see the value in the intermediate options like the Syil benchtop machines.

  4. Anool says:

    Once you put in some upgrades, the ShapeOko is quite stable and useful. Engraving metal would be difficult, but not impossible. The Spindle, as Macona says, is a POS. I’m already looking around for a proper high speed spindle with more bite. The Ras-Pi-AlaMode-GRBLShield combo resides inside the control box, and I log in to it remotely using VMC.

  5. FWIW, there’s a compleat page of spindle options on the ShapeOko wiki:

    http://www.shapeoko.com/wiki/index.php/Spindle_Options

    ranging from the generic dremel up to a 1.5KW spindle which have all been used w/ the ShapeOko. People have cut everything from foam and plastics, to soft and hard-woods, to aluminum, and I’ve got a piece of brass set aside for my next project (still working on a final version of my cigar box tool kit).

  6. Josh Martin says:

    Dewalt 611 with Precise Bits collet will have minimal runout that will allow you to use very small endmills without issues. They are not very loud, under $200 for the setup, and are waaaay better then the Bosch Colts. From what I’ve read the makerslide based machines aren’t gutsy enough for decent routing of wood (EI past cutting out 2d shapes and your actually wanting to produce) when you machine gets past a Shapeoko or so. A Microcarve machine is extremely ridged, and mine has preformed great for two years straight with great demands on accuracy, speed, and repeatability.

    • pcf11 says:

      DeWalt way better than Bosch tools you say? I’m afraid that has not been my experience. DeWalt is Black and Decker, some Bosch tools are still made in Germany. Didn’t Slap Chop Vince teach you anything? You know the Germans make good stuff! A lot of Black and Decker’s manufacturing is done in the far east now. Real far east.

      • Unfortunately, the Bosch Colt PR-20 doesn’t seem to be one of the ones still made in Germany — at least the precision seem to’ve gone downhill a couple of years ago: http://www.precisebits.com/lab_reports/bosch_colt_TIR.htm

        Further, note:
        >An added irritation is the fact that the front spindle bearing is mounted
        >in a plastic (meltable) ring, instead of a heat-sinking metal seat.

        On the other hand, the DWP611 uses metal to encompass its bearings.

        • pcf11 says:

          Maybe Precise Bits should contact Bosch about what they think they have found, instead of whining about it on an obscure web page? Maybe there is some trouble on one of Bosch’s manufacturing lines? Perhaps Bosch is simply manufacturing a hand power tool to a reasonable tolerance too though? In any event I am not going to color my judgement based on the opinions of one small fry out there with their own axes to grind. Put a yellow, and a blue tool in front of me and I’m going for the blue one every time.

          I really have to question the validity of their testing methods. I know for a fact that ink on a metal surface is measurable, so what they suggest is tantamount to arbitrarily shimming up the taper in the spindle. I’m also not sure how reliable a static test is on a high speed spindle either. At speed, and under load is all I really care about. Bosch has the instruments to measure that too. It ain’t no dial indicator on a stand either.

          If they really want to convince me they’re going to have to come up with some real world comparisons. So far all they’ve shown me are things that are suggestive of problems. Not actual problems themselves. Unless of course your end goal is to keep a test indicator’s needle steady. Mine is making chips.

  7. Josh Martin says:

    I am too cheap for calipers (I do “art” so it just has to be really smooth) so I bought a 1/32″ ballmill and I’m going to see how small I can machine some 3d models out of Ebony and corion :)

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