Compact fluorescent grow light

compact-fluorescent-grow-light

Spring is on the way for our friends down under. With that in mind [x2Jiggy] built this compact fluorescent grow lamp to help start the seeds for his garden. He used materials that are easy to find, and multiple bulbs means that you can mix and match their color warmth in order to get the wavelengths of light best for plant growth.

He started by building the box out of MDF. It is lined mostly with a reflector meant to go in your car’s windshield when you leave it in a hot parking lot. He sealed the seams of the reflector using what he calls flashing tape. This is the rubbery type of stuff used as soft flashing around windows.

The bulb sockets came from an old string of party lights. Wiring is run through plastic junction boxes which keeps the setup code-compliant. Each of the CFLs draw 20 Watts for a total consumption of 160 Watts. Combine this with a DIY hydroponic tent and you’ll be eating fresh greens year round.

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Preserve your garden bounty with a solar food drier

solar-food-drier

The [VelaCreations] family lives off the grid, getting the electricity that they actually use from solar and wind power. When they started looking for ways to preserve the fruit and vegetables now coming into harvest the electricity consumption and cost of a food dehydrator made them balk. What they do have plenty of at this time of year is sun and heat, so they built their own solar food drier.

The frame is made of welded square tube. They mention that you will have to alter it if you don’t have welding tools, but building your own MOT welder is just one more fun project to take on. The frame has wood rails to hold the trays of food. It is enclosed with translucent polycarbonate sheets. There is a vent in the top as well as the bottom. As the heat from the sun builds inside, it flows upward, sucking fresh air in the bottom. This carries away moisture from the food and can be regulated by adjusting the size of the bottom vent.

Hack VersaPak battery modules to reuse laptop cells

retrofit-battery-packs-with-laptop-cells

If you’re familiar with VersaPak tools you’ll note that while the battery pack in this image looks somewhat familiar, it’s not supposed to have a removable cell. This is [Martin Melchior's] hack to use laptop 18650 Lithium cells with VersaPak tools.

The original NiCad packs used three cells for a total of 3.6V, so it is possible to substitute a Lithium cell in the same voltage neighorhood. The tools are pretty hard on the battery packs, drawing a lot of current in certain situations. But these cells are being harvested from dead laptop battery packs so it’s not a huge concern if their life is a bit shortened.

The hack places an 18650 battery receptacle inside of the VersaPak battery housing. There’s a bit of careful disassembly to get to this point, but it’s well illustrated in [Martin's] project log. And of course you’ll need to use a proper Lithium battery charger from here on out.

This form factor has been popping up in a lot of hacks lately. Here’s another one that modifies the Goal Zero Bolt flashlight to use them.

Biodiesel equipment hacks

biodiesel_hacks

[Oldman] took on a biodiesel project for some friends a few years ago. A fully operational processing rig was never achieved, but he did document some of the successful hacks he came up during the project.

The idea is to reclaim the waste oil from restaurants and burn it in your modified racing motorcycle or other mode of transportation. That makes it sound easy, but have you ever seen what happens to bacon fat after it cools? Granted, we’re talking oil from vegetable sources but the same type of coagulation presents itself. Pumping it through a processing rig becomes especially tough in the winter, and that’s why [Oldman] came up with the heated pump head on the right. It’s got three connections; two are part of a loop of copper tubing, allowing 150 degree water to be circulated to liquefy the grease. The third connection sucks up the melted oil. You also need to regulate the water content of the fuel. The inset images of a salad dressing jar are his test runs with applying vacuum to dehydrate the fuel. He learned that it needs to be heated slightly to reduce foaming. He had planned to scale up this concept to apply vacuum to fuel stored in propane tanks.

Resole shoes with old tire tread

resole-shoes-with-tires

These shoes are heavier than normal, they don’t grip as well as store-bought, and it’s a heck of a lot of work to make a pair for yourself. But if you do pull this one off you’ll have a great time showing everyone your custom tire tread shoe hack.

Two things motivated [Martin Melchior] to give this a try. The first is that tire tread is virtually indestructible when only supporting the weight of a person. Secondly, this reuses otherwise worn-out tires, making it a recycling project.

Pretty much all of the work has to do with getting the tread ready for use. Cutting off the sidewalls and sawing the ring of tread in half is rather easy. But then you have to split the tread off of the steel belts, which is not. [Martin] recommends using vice-grip pliers to grab the outer lay and pull it away from the tread, slicing along the belts with a utility knife as you go. Once you do have a flat strip just glue it to your shoes and cut away the excess.

We’re more into a different type of retread that actually takes you places.

Beating the heat with geothermal cooling

geo

A while back, [Erich]‘s oil heating system was due for a few repairs. Given the increasing price of fuel oil, and a few incentives from his Swiss government, he decided to go with a more green heating solution – geothermal heating. The system works well in the winter, but it’s basically useless in the summer. [Erich] decided to put his 180 meter investment to work for the summer heat, and made his geothermal heating system into a cooling system with a fairly low investment and minimal cost.

The stock system works by pumping cold liquid from [Erich]‘s under floor heating into the Earth. In winter, the surface is always colder than the ground, thus heating [Erich]‘s home. In the summer, the situation is reversed, with the cool earth insulated by the baked surface. All that was required to reverse the heating system was a few slight modifications to the heating controller.

Stock, [Erich]‘s heat pump controller doesn’t have the capability to run the system in reverse, so he turned to a Freescale board to turn the compressor off and the pump on. With the additions, [Erich] is using 50 Watts to pump 1.5 kW of heat directly into the Earth below, a fairly efficient cooling system that’s basically free if you already have a geothermal setup.

Hardware store goods and an mbed combine help solar panels track the sun

sun-tracking-solar-panels

If you have the space, and can build a tracking rig cheaply you’ll be able to get a lot more out of your solar panels. That’s because they work best when the sun’s rays are hitting them perpendicular to the surface and not at an angle. [Michael Davis] hit both of those stipulations with this mbed powered solar tracker.

At a garage sale he picked up an antenna motor for just $15. The thing was very old, but still wrapped in the original plastic. It’s beefy enough to move his panels, but he first needed a way to mount everything. After checking his angles he built a base out of wood and used galvanized water pipe as an axle. Cable clamps mate his aluminum angle bracket frame to the pipe. This frame holds the panels securely.

To track the sun he used two smaller cells which aren’t easy to pick out in this image. They are monitored by the mbed microcontroller which measures their output in order to point the assembly in the direction which has the most intense light. A couple of limit switches are included to stop the assembly when it reaches either side.

This technique of using small solar cells as the tracking sensors seems to work well. Here’s another project that took that approach.

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