Hackaday Links: Sunday, April 7th, 2013


Let’s wind down the weekend with some projects that didn’t quite warrant their own feature, but we think they’re still worth a look.

First up is a quick tip on cracking the lids on those hard to open jars of food. [Jason] says just grab about a foot of duct tape and the lid will come flying off. And while you’re searching for that roll of tape why not grab some foil tape to build a cooking oven. [Gabriel] built this solar oven by covering curved wedges of cardboard with foil tape and combining them to form a parabolic reflector.

Next we’ve got a trio of hacks that will come in useful in your home shop or at the local Hackerspace. Organization is key, and here’s a resistor storage system that uses #6 envelopes [via Reddit]. Also useful is the tip from [Felix] about using a tile saw to get clean cuts on your circuit boards. And if you’ve ever been plagued by a laser cutter job that doesn’t fully sever the material [Dan] wrote a guide on using a fence so that you can reposition the piece for another run.

Finally, we’re hoping we weren’t the only ones that didn’t realize the Raspberry Pi has an unpopulated footprint for a reset button. Now we’ve got to figure out if it’s okay to leave the PSU plugged in (based on it’s current consumption while the RPi is in power down) and hack together some sort of TV-based reset circuit for our RPi XBMC setup.

Solar powered robot mows your lawn while you chill indoors


We’ve heard quite a number of radio ads lately trying to sell an automatic lawn mowing robot (like a Roomba for your grass). But wouldn’t it be a lot more fun to hack your own from an existing lawnmower? That’s what [Daniel Epperson] did. In fact, the project has been ongoing for years. But he wrote in to share the latest development which adds solar charging capabilities to the robot mower.

First off let’s discuss the fact that this is not an electric lawnmower. This is the Prius of lawnmowers, bringing together hybrid technology to cut the grass with the gasoline powered motor, and to propel the rig with electricity. [Danny’s] worked hard to shoe-horn just about every feature imaginable (other than autonomy) into the thing, and that’s why the batteries can be charged from mains, an alternator powered by the gas motor, and now from the PV panel mounted on top of it. Get the entire project overview in his roundup post.

This a wireless video feed and the mower is driven by remote-controlled. So you can give your yard a trim without getting sweaty. After the jump we’ve embedded a clip of an earlier revision demonstrating that remote control. If you’re not interest in having all the features you could simply build an analog version.

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Acoustic bass guitar uses water jug and two strings


It’s easy to dismiss this one at first glance. But once you hear [Tychsen81] playing the thing you’ll want to know more.

He posted the demonstration way back in 2009. It wasn’t until a year later that he filmed the particulars of how the thing was made. The strings are actually bass guitar strings, an A and D string that are tuned down to E and A to play along with Black Sabbath’s “Ironman”. The neck is made out of two boards. One serves as the fingerboard, which is fretless. The other is mounted under that in order to provide negative space for the bridge while keeping the strings at the right height for the fingerboard. The water bottle helps to amplify the sound and that’s why the bottom end of the strings pivot on the bridge, pass through the neck, and are anchored on the bottom edge of the bottle.

We’ve embedded both the demo and the build videos after the break.

If this gets you thinking about making your own instruments you will also be interested in the Whamola.

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