Copying complex objects in wood

[Matthias], eminent woodworker he is, designed and built an awesome machine to make copies of just about any object imaginable. With a few scrap 2x4s, and a few bolts, screws, and skateboard bearings, you too can copy anything into a solid block of wood.

The theory of operations for [Matthias]‘ copy carver is mounting a router and ‘follower’ to the same piece of wood. Put that on an XY table with a rotation axis, and just about any object can be copied in wood or plastic. It’s not too dissimilar to a Dulplicarver, a routing machine meant to copy everything from gun stocks to guitar and violin bodies.

So far, [Matthias] has copied a rotary phone and a sadly non-functional wrench.  It’s the perfect follow-up for [Matthias]‘ 3 axis pantograph router that can copy and enlarge any random flat object you can throw at it.

via Make

A personal manufacturing Stack Exchange

Over on Stack Exchange, there’s a proposal for a new CNC/3D printer site. It’s a personal manufacturing stack exchange, and hopefully we’ll see some awesome discussion when it’s eventually created.

Stack Exchange is already well-known for hosting the most useful programming site as well as awesome sites/forums covering everything from LaTeX to grammar. The proposed Personal Manufacturing site is sure to provide a ton of advice and discussion covering the hardware, software, electronics, and toolchains of CNC routers, RepRaps and mills.

The personal manufacturing stack exchange hasn’t been created yet – a few more people still need to commit to use it. Once that’s done, though, we’re sure to see a lot of very helpful advice and discussion from the Stack Exchange community.

Kudos to [Michael] for sending this in.

Cheap and easy linear supported rail

Some of the very largest – and coolest – CNC machines use supported linear rail for their movement axes. For any home tinkerer trying to reproduce these supported rails, the problem of cost comes up very quick; these rails can run over $100 for just a few feet. [Michael] came up with a great way to build his own supported rail so he can build his very large CNC router.

There aren’t many tools needed to build [Michael]‘s rail. He put a 90° notch in a 2×4 to support his 25mm rail, and clamped it down with a piece of plywood. After drilling a 5/16″ hole every 12 cm, he tapped these holes out to receive 3/8″ threaded rod. Yes, we also hate the mix of metric and imperial units in that description, but the results speak for themselves.

The now-supported rail was mounted to a piece of MDF with a few bolts and washers. MDF isn’t the most dimensionally stable material, so [Michael] will be covering the whole thing in a coat of epoxy very soon. Now, he’s one step closer to his gigantic CNC gantry router.

You can check out [Michael]‘s demo video after the break.

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Never miss your transport with this bus arrival notifier

[John Graham-Cumming] was all set to start a new project based on the Raspberry Pi. Well, that was until shipment was delayed due to manufacturing issues. Not to fret, he transitioned over to a router board which displays the arrival countdown for mass transit bus service.

He based the build on a web page the Transport for London provided. You can load it up and see if your bus is running on time or not. There’s no published API, but by studying the source code from the site [John] was able to figure out how the JSON commands were formatted.

The next step is building a standalone device to pull the data and display it. The board seen above is from a Linksys WRT54GL router. This longtime favorite has a serial port header which can be driven from the Linux kernel. He wired up a jack on the router’s case, and uses an extension cable to get from it to the 7-segment displays mounted in a model of the bus. Since there’s four digits the display can tell you minutes until the arrival of two different buses.

[Thanks Pseudo Lobster]

Using routers as displays

Have you ever seen an LED display made out of routers? [Sean] took eight Netgear routers and made an 8×4 display out of them. Because that wasn’t cool enough, a very small version of Conway’s Game of Life was added to the build.

Each router is running a copy of OpenWrt, a Linux distro meant for limited hardware. Instead of an 802.11 protocol, each router runs the B.A.T.M.A.N. advanced mesh protocol. This protocol allows each router to communicate with all the other routers.

Instead of each router receiving data from a master, the routers calculate each step in the Game of Life independently.  Once the routers communicate their initial states, each router is responsible for displaying its four LEDs for each new generation. In the video after the break, you can see [Sean]‘s routers calculating random Game of Life boards. Sadly, we didn’t notice a GoL oscillator being randomly generated, but with a 4×8 play field even a Glider wouldn’t last very long.

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A SOPA we still can’t get behind

[Brad] had an extremely productive January 18th. Considering how many websites went dark to protest SOPA, we can’t blame him. While considering what he could get done if popular Internet time sinks went dark on command, [Brad] thought of the Stop Online Productivity Avoidance box. This build will redirect all traffic to sites like reddit, hacker news, and (gasp!) hack a day to a simple web page that asks the eternal question, “shouldn’t you be working right now?”

The box has two modes: in SOPA mode, the whole Internet is at [Brad]‘s fingertips. In NOPA mode, an Arduino communicates with a Python script running on the router to pull up an Internet blacklist. A simple button would be too easy to override, so there’s a ‘nuclear mode’ that shuts off these time sinks for one hour. The only way around the blacklist is to restart the router, a process that takes 15 minutes and will kill the entire Internet for the duration. Not something you’d like to do if you’re slightly bored.

All the code for the SOPA box is up on github and you can check out [Brad]‘s demo of the SOPA box after the break.

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Complete guide to compiling OpenWRT

Regular reader [MS3FGX] recently wrote a guide to compiling OpenWRT from source. You may be wondering why directions for compiling an open source program warrant this kind of attention. The size and scope of the package make it difficult to traverse the options available to you at each point in the process, but [MS3FGX] adds clarity by discussion as much as possible along the way.

OpenWRT is an open source alternative firmware package that runs on may routers. It started as a way to unlock the potential of the Linksys WRT54G. But the versatility of the user interface, and the accessibility of the Linux kernel made it a must-have for any router. This is part of what has complicated the build process. There are many different architectures supported and you’ve got to configure the package to build for your specific hardware (or risk a bad firmware flash!).

You’ll need some hefty hardware to ease the processing time. The source package is about 300 MB but after compilation the disk usage will reach into the Gigabyte range. [MS3FGX] used a 6-core processor for compilation and it still took over 20 minutes for a bare-bones distribution. No wonder pre-built binaries are the only thing we’ve ever tried. But this is a good way to introduce yourself to the inner workings of the package and might make for a frustrating fun weekend project.