DIY Punch Card System Despite Hanging Chads

July 30, 2015 by Elliot Williams 8 Comments

Sometimes you just have parts lying around and want to make something out of them. [Tymkrs] had a robot paper cutter, so naturally they made punch cards. But then, of course, they needed a punch card reader, so they made one of those too. All with stuff lying around the shop.

The Silhouette Portrait paper cutter is meant for scrapbooking, but what evokes memories of the past more than punchcards? To cut out their data, rather than cute kittens or flowers, they wrote some custom code to turn ASCII characters into rows of dots. And the cards are done — you just have to clean up the holes that didn’t completely cut. These are infamously known as hanging chads.

The reader is made up of a block of wood, with a gap for the cards and perpendicular holes drilled for LEDs and photoresistors. This is cabled to a Propeller dev board with some simple firmware. We would have used photodiodes or phototransistors, because that’s what’s in our junk box (and because they have faster reaction time), but when you’ve got lemons, make lemonade.

OK, now that you’ve got a punch card reader and writer, what do you do with it? Password storage comes to mind.

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A Handheld CNC Router

July 26, 2015 by Brian Benchoff 32 Comments

Over the last few years, the state of the art in handheld routers has been tucked away in the back of our minds. It was at SIGGRAPH in 2012 and we caught up to it at Makerfair last year. Now, it’s getting ready for production.

Originally called Taktia, the Shaper router looks a lot like a normal, handheld router. This router is smart, though, with the ability to look at a work piece marked with a tape designed for computer vision and slightly reposition the cutter in response to how the user is moving it. A simple description doesn’t do this tool justice, so check out the video the Shaper team recently uploaded.

With the user moving the Shaper router over a work piece and motors moving the cutter head, this tool is able to make precision cuts – wooden gears and outlines of the United States – quickly, easily, and accurately. Cutting any shape is as easy as loading a file into Shaper, calling that file up on a touch screen display, and turning on the cutter. Move the router around the table, and the Shaper takes care of the rest.

Accuracy, at least in earlier versions, is said to be on the order of a hundredth of an inch. That’s good enough for wood, like this very interesting bit of joinery that would be pretty hard with traditional tools. Video below.

Thanks [martin] for the tip.

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Hardware Store CNC Machine Is Remarkably Precise

July 22, 2015 by Dan Maloney 20 Comments

A vise, a hacksaw and file, some wrenches – the fanciest tools [HomoFaciens] uses while building his DIY hardware store CNC machine (YouTube link) are a drill press and some taps. And the bill of materials for this surprisingly precise build is similarly modest: the X- and Y-axes ride on cheap bearings that roll on steel tube stock and aluminum angles; drives are threaded rods with homemade encoders and powered by small brushed DC gear motors; and the base plate appears to be a scrap of ping-pong table. The whole thing is controlled by an Arduino and four H-bridges.

The first accuracy tests using a ball point pen for tooling are quite impressive. [HomoFaciens] was able to draw concentric circles eyeball-accurate to within a few tenths of a millimeter, and was able to show good repeatability in returning to a point from both directions on both the X- and Y-axis. After the pen tests, he shows off a couple of other hardware store tooling options for the Z-axis – a Proxxon rotary tool with a burr for engraving glass; a soldering iron for cutting styrofoam; and a mini-router that works well enough to cut some acrylic gears.

We’re impressed by this build, which demonstrates that you don’t need a fancy shop to build a CNC machine. If you’re getting the itch to jump into the shallow end of the CNC pool, check out some of the builds we’ve featured before, like this PVC CNC machine, or this $250 build.

[Thanks, ThunderSqueak]

Desktop CNC From Hardware Parts Really Makes The Cut

July 22, 2015 by Kevin Dady 20 Comments

We love shop made CNC mills, so when [joekutz] tipped us off about the desktop sized CNC he just completed, we had to take a look. Each axis slides around on ball bearing drawer slides, and the machine itself is constructed with MDF and aluminum. And the results it produces are fantastic.

The machine’s work area weighs in at 160*160mm with a height of 25mm. Its the table is moved around with a pair of NEMA17 motors and M8 stainless steel threaded rods. Motor control is done with a pair of Arduino’s but they also do double duty with one processing G-code while the other handles the keypad and LCD interface.

The business end is a Proxxon rotary tool whizzing up to 2000RPM, and while [joekutz] hasn’t tried it on soft metals like brass or aluminum, he has successfully cut and engraved wood, plastics and copper clad PCB material.

Be sure to join us after the break for some YouTube videos. [joe] has posted three of a planned five-part-series which aren’t linked to in the project page shown above. to see this machine in action and get a rundown how it all works

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Coin-Op Weather

July 8, 2015 by Dan Maloney 1 Comment

When you have access to your own CNC machine, you tend to make stuff first and ask questions later. That sounds like how [Rui Cabral] came up with a weather station stuffed into a miniature arcade game cabinet.

Standing only about 16 cm tall, the cabinet is quite detailed and resembles the familiar arcade form factor that has consumed countless quarters. It even appears to be made of particle board like the big boys. The screen cutout is filled by a 84×48 monochrome Nokia display, and the rest of the cabinet’s interior is stuffed with a CNC-milled PCB, temperature and humidity sensors, an RTC, and a Bluetooth module for uploading data to a phone. [Rui] even manages to work in an homage to the grand-daddy of all arcade games with a Pong splash screen.

Another good-looking display for this project might have been this ePaper badge made into a weather station. And we’ve featured even tinier arcade cabinets too, though perhaps not as functional.

[Rui] takes us on a video tour of his build after the break.

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On-Demand Paper Clips

July 7, 2015 by Rich Bremer 19 Comments

3D Printers are great for printing out parts or items you need, but can they really help if you run out of paper clips? Yes, the all important and extremely overlooked bent metal fastener can put a serious damper on your day if not readily available. There is a solution to this problem, it’s called the Paper Clip Maximizer 1.0. The only consequence of using such a machine may be the destruction of mankind.

The machine takes a spool of wire and methodically bends it into a paper clip shape. Just like an extruder on a 3D Printer, there is a knurled drive wheel with a spring-loaded bearing pinching the wire. This drive wheel is powered by an RC servo that has been modified for continuous rotation. After the drive mechanism, the wire passes through a sturdy guide block. Upon exit, the wire finds the bending head, also powered by a servo. There is a bearing on the end of the bending head that is used to bend the wire around the guide block. After making several bends to form the paper clip, the bending head swings around to cut off the newly manufactured clip with an abrasive wheel. Unfortunately, this part of the process doesn’t work well. The cutoff wheel motor is powered directly by the Arduino that controls the entire machine, the power output of which is not enough to easily cut the wire. It can also leave a sharp burr on the cut wire which is not a great feature for paper clips to have. But we just see these as future fodder for hacking sessions!

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Rotary Indexer Gives Mill A 4th Axis (sort Of)

July 4, 2015 by Anool Mahidharia 23 Comments

Rotary indexer’s are standard issue in most machine shops. These allow you to hold or chuck a work piece, and then a graduated handle lets you to rotate the workpiece. Useful when you want to drill or tap axial or radial features. A rack and pinion drive ensures that the workpiece does not move under machining load. Quite often, these indexers also have a manual lock to take care of gear backlash and play. Automating them is not too difficult either. You could use just a stepper motor (open loop) or servo+encoder (closed loop) to drive the turntable.

[smashedagainst] needed to drill six radial holes on a part. And he had to do it on 500 pieces for a total of 3000 holes. That was just for the first initial run, with more drilling likely in the future. The part in question was small and light weight. So instead of using a heavy duty, industrial grade unit, he built an all-electric rotary indexing jig using a stepper motor and an Arduino, giving him a sort of rotary 4th axis. His idea was to directly use the stepper motor to rotate the workpiece without any gearing, but he needed to build his own rig to do so.

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