3D Printed CNC Knee Mill

CNC mills will never match real heavy metal mills on hard materials, but that won’t stop people from pushing the limits of these DIY machines. One of the usual suspects, [Ivan Miranda] is at it again, this time building a knee mill from aluminum extrusions and 3D printed fittings. (Video after the break.)

Most DIY CNC milling machines we see use a gantry arrangement, where the bed is fixed while everything else moves around it. On most commercial metal milling machines, the table is the moving part, and are known as knee mills. In the case of [Ivan]’s mill, the table can move 187 mm on the X-axis and 163 mm on the Y-axis. The 1.5 kW spindle can move 87 mm in the Z-axis. All axes slide on linear rails and are driven by large stepper motors using ball screws. The table can also be adjusted in the Z-direction to accept larger workpieces, and the spindle can be tilted to mill at an angle.

To machine metal as [Ivan] intended, rigidity is the name of the game, and 3D printed parts and aluminum extrusion will never be as rigid as heavy blocks of steel. He says claims that the wobble seen on the video is due to the uneven table on which the mill was standing. Of course, a wobbly base won’t be doing him any favors. [Ivan] also had some trouble with earthing on the spindle. He nearly set his workshop on fire when he didn’t notice tiny sparks between the cutter and aluminum workpiece while he was cooling it with isopropyl alcohol. This was solved with the addition of the grounding wire.

While the machine does have limitations, it does look like it can machine functional metal parts. It could even machine metal upgrades for its 3D printed components. One possible way to improve rigidity would be to cast the frame in concrete. [Ivan] has built several other workshop tools, including a massive 3D printer and a camera crane. Continue reading “3D Printed CNC Knee Mill”

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Hackaday Links: March 29, 2015

Every once in a while, the Hackaday Overlords have a Hardware Developers Didactic Galactic in San Francisco. Last week was #06 featuring [Mike Estee] from Othermill and Hackaday writer [Joshua Vasquez] talking about synthesizing an SPI slave in an FPGA. Video here.

It’s no secret that [Fran] is building a DSKY – the part of the Apollo guidance computer that was on-screen in Apollo 13. It’s time for a project update, and here’s where she stands: if anyone has a source of JAN-spec Teledyne 420 or 422-series magnetic latching relays (they’re in a TO-5 package), contact [Fran]. The backplane connector has been identified; it’s a Teradyne I/O 100 series connector with a 120mil spacing. Contact [Fran] if you know where to get them.

Let’s say you want a carbon fiber quadcopter frame. What’s the most reasonable thing you can do? 3D print a CNC machine, obviously. That’s a 200mm FPV racer cut from 1mm and 3mm carbon fiber sheets, but the real story here is the CNC machine. It’s a PortalCyclone, and even the cable chains are 3D printed.

What does an AMOLED display look like up close? Pretty cool, actually. That’s 20x magnification, and it’s not a Bayer filter. Can anyone fill us in on the reason for that?

Laser cutters are tricky if you want to do grayscale or half tones. [oni305] made an Inkscape extension to generate better GCode for engraving with a laser cutter.

19″ racks have no dimensions that are actually 19″. Also 2x4s aren’t 2 inches by four inches. Somehow, a 2×4 server rack works.