Grow Your Own Fresh Salad Year Round With This Cheap Hydroponic Setup

September 16, 2011 by Mike Szczys 53 Comments

With fall approaching you might think about moving your gardening inside. [Jared] used cheap and readily available materials to make these salad-green trays. When used with his grow lights and tent (which he built during a different project) he was able go from seed to salad-bowl in just four weeks.

A pair of plastic storage bins act as the base, keeping the water right where it should be. Some holes cut into a piece of solid foam insulation holds a set of plastic pots in place, allowing the water to leech into the Rockwool that holds each plant in lieu of soil. To aerate the water [Jared] grabbed a cheap aquarium pump, splitting the output into several different branches. Each has its own check valve to ensure that a pump failure doesn’t let the water find its way out of the plastic tube. A set of bubble stones breaks up the output, helping to mix it with the water.

This isn’t quite as easy to pull off if you don’t already have a grow light. But you can always make it worth the investment if you decide to start next summer’s garden from seed. Or perhaps you can try to make your own using a varation of this shop lighting hack.

[Thanks Jayson]

Engine Hacks – A DIY Methane Generator

September 11, 2011 by Jeremy Cook 19 Comments

All “methane generator” jokes aside, This one actually serves a useful purpose. Although not an engine hack per se, methane can be used to run an engine. As the traditional method of powering an internal combustion engine, gasoline, gets more and more expensive, alternatives will have to be found. If you happen to live on a farm, or have access to a source of organic waste, this method could serve as a viable one.

One would need quite a bit of waste, as each kilogram yields around 400 liters of methane gas. This amount is enough to run a gas light for around 4 hours. Any sort of useful engine would require quite a bit more than this (chicken farm possibly?).

A process for converting waste to fuel is illustrated in the video after the break. Extreme caution should be used if attempting to do something like this. There is a danger of not only flammable gas leaking and catching on fire or exploding, but the organic material can be quite toxic as well. Continue reading “Engine Hacks – A DIY Methane Generator” →

High Efficiency Solar Charger Circuit Tops Off Those Lead-acid Batteries

September 10, 2011 by Mike Szczys 21 Comments

Make your next project solar-powered with this charging circuit. It’s completely through-hole, and there are no microcontrollers that need to be flashed. If you can source parts and are handy with a soldering iron building this will be a breeze.

Both the maximum system voltage and the low voltage drop out are configurable. After assembly, you just need to attach a regulated power supply to the load terminals. Tune the power supply to the max voltage and turn a potentiometer until an LED comes on, then repeat the process for the drop out voltage. Board artwork for the two-sided PCB and a schematic are available from the page linked at the top. If you’re not into etching your own circuit boards you can buy one for around $10.

[Thanks Murray]

Repeat Timer Hacked For 35 Minute Hydroponic Cycles

September 9, 2011 by Mike Szczys 29 Comments

[GrowColt] shows you how to modify a lamp timer for use with hydroponics. You can pick up this type of mechanical timer at most local big box stores for around $5. The timer plugs into an outlet, and the device you want to operate plugs into it. [GrowColt’s] end goal is to make the timer repeat every 35 minutes, routing power to the connected device for about 50 seconds each cycle. It will operate the pumps and misters in his hydroponic garden to keep the plants hydrated and keep the nutrients flowing.

We’ve embedded his detailed process after the break. It’s not all that difficult, requiring a few common hand tools, some glue, and rubber washer. There’s a gear box inside which controls the timer. Reorganizing that gearing makes it repeat more frequently.

Not into hydroponics, but looking for watering help with your greenhouse? Check out this system which monitors water sensors and dispenses H2O accordingly.

Continue reading “Repeat Timer Hacked For 35 Minute Hydroponic Cycles” →

Winterizing: Keeping The Drafts Out Of Double-hung Windows

August 23, 2011 by Mike Szczys 22 Comments

[Rumplestiltskin] has had work done on his double-hung windows to help prevent drafts and keep them in good working order. But there are still a few that rattle, and let in the cold of winter. Not this year; he’s added a small feature to the jamb that will keep out the cold weather.

A pair of jointing blocks were added to each window. The small block seen above is attached to the window jam with a couple of all-purpose screws, and hosts a machine screw which points toward the window frame. Since there is weather stripping between the two window frames, and between the frame and the outer jamb, tightening this screw will snug the frames up to close any small gaps. This has the unintended consequence of prohibiting the window from being opened (unless you don’t mind scraping the paint as the machine screw slides across the wood). But if only used in the winter months this is a viable solution.

Setting It Straight About Science Fair Solar Energy Breakthrough

August 22, 2011 by Mike Szczys 58 Comments

There’s been a lot of stories about arranging solar panels to mimic leaves on a tree, thereby boosting their efficiency. But before reading that story you might want to check out this blog post correcting some flaws in that breakthrough (page is down, here’s a cached version).

Before we go any further, we’d like to point out that the original work was done by a seventh grader. He looked at leaves on trees and postulated that the Fibonacci sequence can be found in the layout of leaves, and that by laying out solar cells in the same way you can capture more sunlight. Comments can get negative fast around here, so remember that trashing his work may discourage other kids from participating in science fair events.

Anyway, long story short: there were some issues with original assumptions, and about what was actually being measured during testing. The article linked at the top covers the fact that the cells were not measured under load, and that simple calculations can show why the tree-mimicking-cell-placement can be proven sub-optimal to 45 degree, south-facing solar farms.

[Thanks Jeffery and Steve for the original article and Brian for the follow-up article and cached link]

Feel The Hum Of Electricity Between Your Legs

August 10, 2011 by Mike Szczys 21 Comments

Here’s a little eye candy for motorcycle enthusiasts everywhere. This is the newest iteration of [Julian’s] electric motorcycle. He obviously knows what he’s doing because everything fits into the frame in a way that is still very pleasing to the eye. But this is actually slimmed down from the original design. If you take a look a back at some of his older posts you’ll see that the four relatively small lithium batteries are a new addition.

The frame was designed to hold four lead-acid batteries. Those things really take up a lot of space and add considerable weight to the vehicle. His recent upgrade was also accompanied by a re-gearing that allows him to reach higher speeds (although he doesn’t say what the top speed actually is). You can’t really see it above, but [Julian] included a wooden insert where the tank on a gasoline motorcycle would have been. It houses control switches as well as a 48V voltmeter. It’s a fantastic finishing touch like the cherry on a sundae.