PCB Milling Hell Sunday Extra


I’ve spent about 18 of the last 24 hours working on milling a PC board for my upcoming how-to. So far I’ve murdered several copper clad boards, built a hold down table, redesigned the board in eagle at least five times and snapped off a $15 half round engraving bit.

If you’re wondering, my new board milling table is a piece of MDF that I laser etched a .25″ grid onto, then added some aluminum strips to act as hold-downs. On the side of the strip opposite the board, I put thin slices of PC board to level out the hold downs. As usual, I’m building the board in eagle. To turn the board into something the mill can handle, I’m using pcb-gcode, a nice little g-code generation tool for eagle. I may switch methods later, but if I can get the settings tweaked, it’ll make my design to board milling process very fast.

[Scott] sent in the beginning of his attempt to build a frequency detector. He’s started out with just simple LCD matrix. Nothing intensely interesting just yet, but I like it when people send in stuff they’re working on.
If you haven’t checked out the Arduino yet, do it. It’s the easiest micro controller dev platform I’ve seen. If you’ve got one, now you can hook up a Wii-Nunchuck to it. If you like smaller and cheaper, check out [ladyada]’s boarduino.

[eliot] wanted me to mention this video on hacking drive through speakers. It’s a bit cheesy – and all I could think of was Thunder Run – where the geek character swapped the crystals in the CB radios. (Warning, The FCC might have some expensive words for you if you get caught.) Update: this is what you get if you don’t watch the entire video and catch the joke about taking apart toasters.

Tomorrow I should be picking out some winners for my laser etched laptop (or whatever) offer. You can still win some free etching time! Just send in a tip! The winners are selected from the ones that get published on Hack-A-Day.

Hackit: A Better Homebrew Control Interface?


I’ve built a few CNC controllers, and I’ve been a bit disappointed by the state of the control interfaces. Most diy systems rely on a parallel port interface, while a few use a serial connection. Just one that I’ve seen has an actual USB interface, but it’s limited to use with the fab@home software for now.
So what’s the hackit of the day? I think that the hardware hacking, home fabrication community could really benefit from a standardized I/O interface for driving CNC machines, robotics or anything else along those lines. For CNC work, it’ll need a serial or parallel port emulation scheme to allow existing software to take advantage of it. For quicker home development, some simple API’s for controlling the device would be excellent. Imagine using perl to develop robot logic with just a few easy function calls…

Hackit is really your show, so lets hear your ideas.

CNC Mini-lathe


Given my obsession of CNC projects, I’m surprised that we haven’t mentioned this project before. [Dave] put together an excellent site about his CNC converted mini-lathe. (The same on that I’ve got) He built a pretty simple stepper controller to drive it. Since the lathe only needed two axis motors, he drove the steppers with some mosfets that he triggered from a parallel port. The site has been around for a while, but I thought you guys would enjoy a classic hack like this one.

Nixie Counter Clock


[lerneaen hydra] sent in his version of the ubiquitous nixie clock. Rather than gut his counter for the tubes, he used an Atmel Mega88 to pulse the clock to display the time. Additionally, the LED matrix on the case outputs the time in binary. His past projects are worth checking out. He milled the case on his converted CNC mill, retrofitted an old CNC lathe and seems to enjoy putting supercaps in everything (including his clock).

DIY Rotomolding


Rotomolding is used to create hollow forms by slowing rotating a mold while the material covers and hardens to the shape of the mold. [ds] built this version using a stepper motor to drive the assembly and a belt drive link An extreme version is used to form whitewater kayaks and other plastics. This thread over at cnczone has a rotisserie oven version that looks ideal for small plastic or wax molding.

Frostbot: CNC Cookie Frosting


[Brian Schmalz] sent in his Frostbot. It’s a fun CNC bot project that he built to frost cookies for his latest holiday party. He (wussed out a bit) and started with a kit based CNC machine, but he made up for it by driving it with his own control hardware (that sparkfun happens to have for sale). His USB bit wacker interface certainly looks interesting – I might consider adding it in front of the stepper controllers on my cnc mill. Especially interesting is the HPGL interpreter software that converts graphics to stepper commands via the bit whacker interface.