Turn By Wire Is A Machinist’s Sixth Sense

March 24, 2020 by Sonya Vasquez 14 Comments

It’s hard not to be a little intimidated by the squeaks and whirs that come with your first journey into a machine shop. Here, skilled machinists pilot giant hunks of cast iron that turn metals into piles of chips to yield beautiful parts. But what if machine tools themselves didn’t have to seem so scary. What if using them could feel a bit more intuitive, even, dare we say, natural from the get-go?

Enter Turn by Wire, a unique set of force feedback and machine control concepts applied to a lathe brought to you by researchers [Rundong Tian], [Vedant Saran], [Mareike Kritzler], [Florian Michahelles], and [Eric Paulos] at Berkelely.

Turn by Wire vastly reimagines the relationship between a user’s control inputs and the machine outputs in two ways: (1) by changing the mapping between the hand cranks and machine movements and (2) by changing the haptic feedback felt by the machinist. Since both of these interactions can be defined programmatically, the researchers created three unique ways of interacting with the lathe. First, by defining a tool path in the graphic user interface (GUI), the machinist can use a single hand crank to step forward and back in time along that toolpath. Second, by applying virtual guidelines in the GUI, both the machine and the hand cranks will physically snap to the guide lines when they are sufficiently close. Finally, the hand cranks can be used to teach the machinist a technique by adding resistive forces into the hand cranks depending on movement while a machinist is stepping through a process like peck drilling.

This is a great example of [Tom Knight’s] “just wrap a computer around it!” as mentioned by [Bunnie Huang] when we featured the IQ Motor Modules. It’s a powerful example of how putting a computer between the controls and the machine can correct for real world imperfections, be they in the mechanics of the machine of the operator. For the curious, have a look at [Rundong’s] paper published at UIST and [Vedant’s] master’s thesis.

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A Boring Tale With Six Sides

March 23, 2020 by Jenny List 18 Comments

Making a hole in a piece of material is a straightforward process, after all most of us will have some form of drill. If we need a hole that isn’t round though, after the inevitable joke about bad drill control leading to oval holes, what do we do? Get busy with a file perhaps? Or shell out for a shaped punch? [Skunkworks] has taken a different tack, using LinuxCNC and a vertical mill to machine near-perfect hexagonal and other polygonal holes.

The tool path appears to be more star-shaped than polygon shaped, the reason for which becomes apparent on watching the videos below the break as the rotation of the tool puts its cutting edge in a polygonal path. Anyone who has laboured with a file on a round hole in the past will be impressed with this piece of work.

The latest in the saga takes the work from simple hexes into other shapes like stars, and even tapered polygonal holes. These in particular would be a significantly difficult task by other means, so we look forward to what other developments come from this direction.

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Desktop PCB Mill Review

February 29, 2020 by Al Williams 19 Comments

[Carl] wanted to prototype his circuits quickly using printed circuit boards. He picked up a Bantam Tools Desktop PCB Mill and made a video about the results. His first attempt wasn’t perfect, as you could notice under the microscope. A few adjustments, though, and the result was pretty good.

Be warned, this mill is pretty expensive — anywhere from $2,500 to $3,000. The company claims it is a better choice than a conventional cheap mill because it uses a 26,000 RPM spindle and has high-resolution steppers. Because of its low backlash and high accuracy and repeatability, the company claims it can easily mill boards with 6 mil traces.

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Tangential Oscillating Cutting Knife Makes Parts From The Ups And Downs

February 27, 2020 by Sonya Vasquez 21 Comments

If you thought using a utility knife manually was such a drag, you’re not alone. [luben111] took some initiative to take the wear and tear off your hands and put it into a custom machine tool they call TOCK, or Tangental Oscillating Cutting Knife. TOCK bolts onto your typical CNC router, giving it the ability to make short work of thin materials like cardboard. Rather than apply a constant downward pressure, however, TOCK oscillates vertically at high speeds, perforating the material while cutting through it at a respectable clip.

TOCK’s oscillations are driven by a radially symmetric cam mechanism, allowing the blade to completely pivot full circle while still performing the oscillations. While traditional inexpensive methods for bolting a blade to a CNC machine passively swivel along the path they’re directed, [luben111] has taken the generous extra step of powering that axis, commanding the blade to actively rotate in the cutting director with a custom script that converts PLT files to G-code. The net result is a tool that preserves a tremendous amount of detail in cumbersome thick materials, like cardboard. Best of all, the entire setup is documented on the Thingiverse with CAD files and light instructions. A few folks have even gone so far as to reproduce their own!

It’s great to see some dabbling in various disciplines to produce a working machine tool. As far as knives go, we’re starting to see a good spread of other utility knife augmentations and use cases, whether that’s a traditional CNC retrofit or a solid attempt at a homebrew ultrasonic mod.

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New Part Day: The Wi-Fi Stepper Gets Ideas Working Faster

February 10, 2020 by Donald Papp 38 Comments

Like most of us, I sometimes indulge in buying a part for its potential or anticipated utility rather than for a specific project or purpose. That’s exactly how I ended up with the WSX100 Wi-Fi Stepper, a single board device intended to be one of the fastest and easiest ways to get a stepper motor integrated into a project. Mine came from their Crowd Supply campaign, which raised money for production and continues to accept orders.

What’s It For?

The WSX100 Wi-Fi Stepper Driver (with motor), by Good Robotics

The main reason the Wi-Fi Stepper exists is to make getting a stepper motor up and running fast and simple, in a way that doesn’t paint a design into a corner. The device can certainly be used outside of prototyping, but I think one of its best features is the ability to help quickly turn an idea into something physical. When prototyping, it’s always better to spend less time on basic bits like driving motors.

In a way, stepper motors are a bit like RGB LEDs or LCD displays were before integrated drivers and easy interfaces became common for them. Steppers require work (and suitable power supplies) to get up and running, and that effort can be a barrier to getting an idea off the ground. With the Wi-Fi Stepper, a motor can be fired up and given positional commands (or set to a speed and direction) in no time at all. By sending commands over WiFi, there isn’t even the need to wire up any control logic.

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CNC Hot-Wire Cutter Gives Form To Foam

February 1, 2020 by Dan Maloney 12 Comments

Rapid prototyping tools are sometimes the difference between a project getting off the ground and one that stays strictly on paper. A lightweight, easy-to-form material is often all that’s needed to visualize a design and make a quick judgment on how to proceed. Polymeric foams excel in such applications, and a CNC hot-wire foam cutter is a tool that makes dealing with them quick and easy.

We’re used to seeing CNC machines where a lot of time and expense are put into making the frame as strong and rigid as possible. But [HowToMechatronics] knew that the polystyrene foam blocks he’d be using would easily yield to a hot nichrome wire, minimizing the cutting forces and the need for a stout frame. But the aluminum extrusions, 3D-printed connectors. and linear bearings he used still make for a frame stiff enough to give clean, accurate cuts. The addition of a turntable to the bed is a nice touch, turning the tool into a 2.5D machine. The video below details the construction and goes into depth on the toolchain [HowToMechatronics] used to go from design to G-code, including the tricks he used for making a continuous path, as well as integrating the turntable to make three-dimensional designs.

Plenty of hot-wire foam cutters have graced our pages before, everything from tiny hand-held cutters to a hot-wire “table saw” for foam. We like the effort put into this one, though, and the possibilities it opens up.

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A Ploopy Pick And Place

January 23, 2020 by Dan Maloney 11 Comments

A fair number of hackers reach that awkward age in their careers – too old for manual pick and place, but too young for a full-fledged PnP machine. The obvious solution is to build your own PnP, which can be as simple as putting a suction cup on the Z-axis of an old 3D-printer. Feeding parts into the pick and place, though, can be a thorny problem.

Or not, if you think your way through it like [Phil Lam] did and build these semi-automated SMD tape feeders. Built for 8-mm plastic or paper tapes, the feeders are 3D-printed assemblies that fit into a rack that’s just inside the work envelope of a pick and place machine. Each feeder has a slot in the top for the tape, which is advanced by using the Z-axis of the PnP to depress a lever on the front of the case. A long tongue in the tape slot gradually peels back the tape’s cover to expose a part, which is then picked up by the PnP suction cup. Any machine should work; [Phil] uses his with a LitePlacer. We like the idea that parts stay protected until they’re needed; the satisfyingly clicky lever action is pretty cool too. See it briefly in action in the video below.

It looks like [Phil] built this in support of his popular Ploopy trackball, which is available both as a kit and fully assembled. We think the feeder design is great whether you’re using PnP or not, although here’s a simpler cassette design for purely manual SMD work.

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