Video Gives You The Basics Of DIY Rotary Encoders

January 8, 2016 by Dan Maloney 45 Comments

Is it really possible to build a rotary encoder out of a flattened tin can and a couple of photodetectors? Sure it’s possible, but what kind of resolution are you going to get from such a contraption? Is there any way that you’d be able to put them to work in a DIY project like a CNC router? If you pay attention to the basics then the answer is yes, and [HomoFaciens] wants to prove that to you with this detailed video on homebrew encoder design.

Faithful Hackaday readers will no doubt recognize [HomoFaciens] from a number of prior appearances on these pages, including this recent hardware store CNC router build. When we first ran across his builds, we admit a snicker or two was had at the homemade encoders, but if you watch the results he manages to get out of his builds, you quickly realize how much you can accomplish with very little. The video is a primer on encoder design, walking you through the basics of sensing rotation with phototransistors, and how a pair of detectors is needed to determine the direction of rotation. He also discusses the relative merits of the number of teeth in the chopper; turns out more isn’t necessarily better. And in the end he manages to turn a car wiper motor into a high-torque servo, which could be a handy trick to have filed away.

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Make PCBs With DLP, OMG!

January 7, 2016 by Elliot Williams 48 Comments

There’s so many ways to skin the home-fabrication-of-PCBs cat! Here’s yet another. [Nuri Erginer] had a DLP projector on hand, and with the addition of some reducing optics, managed to turn it into a one-shot PCB exposer.

If you’ve ever used photo-resist PCB material before, you know the drill: print out your circuit onto transparency film, layer the transparency with the sensitized PCB, expose with a UV light for a while, dissolve away the unexposed resist, and then etch. Here, [Nuri] combines the first three steps in one by exposing the board directly from a DLP projector.

The catch is that the projector’s resolution limits the size of the board that you can make. To fab a board that’s 10cm x 10cm, at XGA resolution (1024×768), you’ll end up with a feature size of around 0.004″ in the good direction and 0.005″ in the other.

For DIP parts, that’s marginal, but for fine-pitch or small SMT parts, that won’t do. On the other hand, for a smaller board, optimally one in the same 4:3 ratio, it could work. And because it exposes in one shot, you can’t beat the speed. Cool hack, [Nuri]!

When you need more precision, strapping a UV laser to an accurate 2D robot is a good way to go, but it’s gonna take a while longer.

Hillbilly Lego Focus Puller

January 1, 2016 by Elliot Williams 10 Comments

There’s almost nothing you can’t build with the right set of Lego parts. [Rigjob] built up a Lego-based wireless remote follow-focus system that’ll give professional systems a run for their money.

Now [Rigjob] self-identifies as a hillbilly, but he’s not just a redneck with a camera. He’s set up the Lego controller to remember minimum and maximum focus positions as well as mark points along the way. The controller simply won’t turn the lens outside of the focus range, and an interactive graph shows you where you are within the range. For a focus wheel, he uses (drum-roll please!) a Lego off-road wheel. It looks really comfortable, usable, and actually quite professional.

There’s a lot of tech in the Lego controller and motors that make this “simple” hack simple. Under the hood, there’s a Bluetooth connection, a geared stepper motor with a position sensor, a communication protocol, and a whole ton of programming in the Lego controller that makes it all drag-and-drop programmable. But to a long-bearded hillbilly cameraman, it all looks like child’s play. And that’s the hallmark of good design. Kudos, Lego.

If you can’t get enough Lego camera tech, check out this DIY slit-scan stargate rig, or (what else?) a Lego 3D chocolate printer.

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Sourcing Your CNC Tools In 2016: Buy Them

December 30, 2015 by Sonya Vasquez 43 Comments

Hobbyist 3D printers have had a home in the maker space for years now. Along the way, they’ve left a mark in our imaginations. They’ve tickled our fancy for watching a computer orchestrated symphony written in G-code hum away while cranking out parts. They’ve opened a door to the idea that while computer controlled machines may be decades old, having one or two homebrew setups in our garage might not be as far-fetched as we first thought. Now that we’ve seen the steppers and linear slides that go into these setups, it’s not unreasonable for many of us to start asking: What else? Perhaps a computer numerically controlled (CNC) lathe, mill, or even a laser cutter–anything that would add to the vocabulary of tools and techniques that we’re starting to build at home.

VSlot linear rail system for building multiaxis linear actuator systems

Since 3D printers have become somewhat commonplace, it’s not too difficult to find commodity spare parts spilling to the surface of online vendors’ websites. We can even find kit versions for building our own variants. Now that the notion of CNC-at-home is here to stay, the question for 2016 is: do we build our own CNC tools or buy them?

Despite the countless CNC build logs, extruded aluminum kits, and open source G-code interpreters, I’m still convinced that unless your needs are truly custom, buying the machine that fits your needs will have you putting together projects faster and with far less maintenance than you’d need if you assembled the machine yourself. In what follows, I thought I’d explore a few machines that we can find today in 2016 that make the dream of desktop fabrication a reality.

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Danielle Applestone And The Story Of Every Othermill

December 14, 2015 by Sonya Vasquez 42 Comments

Many of us may qualify as “makers,” but how about a “maker of machines?” [Danielle Applestone] tells us what kinks to look for whilst embarking on your hardware startup adventure. Co-founder of Other Machine Co, the company that makes a PCB Mill that holds tolerances as tight as a thousandth of an inch, [Danielle] holds degrees in chemistry and materials science from MIT and UT Austin. While she may tell you that the math for running a hardware company is easy, knowing what numbers to crunch and keeping track of them has been part of her key to success. So take 20, and give yourself a moment to take in [Danielle’s] tips from her Hackaday Superconference talk on beating the hurdles ahead in the land of hardware startups.

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Laser-cut Cardboard Planetary Gearset Is Pretty, But Useless

November 22, 2015 by Elliot Williams 11 Comments

[Shane] made a project that speaks directly to our heart — combining laser cutting, cardboard, and gears. How could it be any better? Well, it could do anything. But that’s quibbling. It’s fun enough just to watch the laser-cut cardboard planetary gears turn. (Video after the break.)

It was made on a laser cutter using the gear extensions for generating gears in Inkscape, everybody’s favorite free SVG editor.

In his writeup, [Shane] touches on all of the relevant details: all of the gear pitches need to be the same, and the number of teeth in the sun gear (in the center) needs to equal the number of teeth in the ring (outside) divided by the number of planets (orbiting, in the middle). So far so good.

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Garbage Can CNC Machine Build

November 21, 2015 by Dan Maloney 41 Comments

Forget sourcing parts for your next project from some fancy neighborhood hardware store. If you really want to show your hacker chops, be like [HomoFaciens] and try a Dumpster dive for parts for a CNC machine build.

OK, we exaggerate a little – but only a little. Apart from the control electronics, almost everything in [HomoFacien]’s build could be found by the curb on bulk-waste pickup day. Particle board from a cast-off piece of flat-pack furniture, motors and gears from an old printer, and bits of steel strapping are all that’s needed for the frame of a serviceable CNC machine. This machine is even junkier than [HomoFacien]’s earlier build, which had a lot more store-bought parts. But the videos below show pretty impressive performance nonetheless.

Sure, this is a giant leap backwards for the state of the art in DIY CNC builds. but that’s the point – to show what can be accomplished with almost nothing, and that imagination and perseverance are more important for acceptable results than an expensive BOM.

With that in mind, we’re throwing down the gauntlet: can anyone build a CNC machine from cardboard and paperclips?

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