Foam is all kinds of useful, but trying to cut it with scissors or a serrated plastic knife is usually an exercise in futility. What you really need is a hot wire for nice clean cuts. [Elite Worm] built a hot wire foam cutter that can cut any type of foam with ease, be it Styrofoam or grey craft foam.
There are a ton of ways to heat up a taut piece of nichrome wire, but few of them are as good looking as this one. [Elite Worm] designed and printed a table with an adjustable fence so it can be used like a table saw. There is also a circle-cutting jig that looks really handy.
This design uses a 12 V power regulator to heat up a piece of tension-adjustable nichrome wire for buttery smooth cuts. This thing looks fantastic all the way down to the cable management scheme. All the files are available on Thingiverse if you want to build one for yourself, but you’ll need to use something other than PLA.
This wire cutter is pretty versatile, but you could go even smaller with a handheld version, or build a larger, CNC-based machine.
Continue reading “Hot Wire Foam Cutter Does Circles, Too”
If you want to run your Raspberry Pi from something other than a mains power converter, and you’ve got some courage to spare, this hack is right up your alley. [Tom] wrote in with a switch mode power replacement for the RPi’s stock linear regulator. This is the first hack we’ve seen where the RPi’s on-board hardware is being altered and that’s where things get a little scary.
The first thing done was to remove the linear regulator, leaving the unpopulated RG2 footprint seen above. Apparently a rework station wasn’t available as the technique they used describes holding the board up by gripping the regulator with tweezers, then blasting it with a hot air gun. It makes us a bit queasy because the processor chip has a solder footprint you don’t want to mess with.
But apparently all is still well. With the wasteful linear regulator gone a pair of 5v and 3.3V switch regulators inject voltage through the GPIO header. Initial tests show a savings of around 25% but we’d imaging this varies greatly based on load.