Phase one of a robot coffee maker

coffee fry

A coffee machine that brews a fresh pot of joe,  automatically putting coffee in a filter, filling the coffee maker with water, brewing, dumping the grounds, and adding sugar and cream, all without any human interaction. Some may call it the fevered dream of a madman. Others may call it a vending machine. All we know is [Phil] is working on his own version of this robot par excellence.

This is only phase one of a robotic coffee machine build, but so far [Phil] has a single cup coffee maker that can fill itself with water and dump its grounds automatically.

The electronics are based on a PIC18F4550 that controls two mechanical relays that control the solenoids, one solid state relay that controls power to the coffee maker, and two stepper motor drivers that open the lid of the coffee maker and dump the filter into the wash bin.

It’s an awesome build and we look forward to the next stage of this awesome, truly homebrew build.

 

A drip coffee maker for camping

drip

[TE] goes camping, and on his excursion he likes to take just the bare necessities. A sleeping bag, a tent, food, but above all else, coffee. Most camping coffee makers are a percolator design, which is widely regarded as the worst way to make coffee ever. With a little bit of ingenuity, he created an improvised drip coffee maker for camping, just the thing for a nice cup of brew in the wilderness.

If you were to make your own drip coffee maker, your first inclination might be to use a funnel, put in a filter, pour in some coffee, and load it up with hot water. This was [TE]‘s first design, but he quickly realized the hole in the bottom of his makeshift funnel would clog very quickly. After investigating his electronic drip coffee maker, he discovered the bottom of the basket had a series of baffles that allowed the filter to drain over its entire bottom surface. But how to replicate this in a piece of DIY equipment?

The solution came from [TE]‘s wife, who pulled out an apple slicer. This allowed the filter to sit a little proud in the basket, allowing for an efficient draining of coffee. Simple, effective, and nearly impossible to break; that’s very good camping equipment.

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Making S’mores with 50,000 Volts

Cooking a Marshmallow with HV

[Skyy] sent us a video of him cooking s’mores with an electric arc. He’s using a flyback transformer with a zero voltage switching (ZVS) driver. This produces about 50 kV, which is more than enough to toast the marshmallow.

ZVS is a technique that triggers the semiconductor switches when they have zero voltage across them. This ensures that there’s minimal heat created by the switches, since they are not interrupting any current at the time they are toggled. ZVS is also used in lighting dimmers to switch off power without creating interference.

If you’re interested in the details, there’s a great tutorial on building the driver. If you’re interested in learning how it works, check out this simulation video.

[Skyy] admits that his setup isn’t terribly safe since it uses a breadboard, which isn’t rated for the high voltages and currents. Keep in mind that these circuits could kill you. After the break, watch a marshmallow fry in a 50 kV arc.

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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.

Copper kettle just for the hipster coffee scene

04-copper-kettle

Handmade coffee is a feature we need to write. But for now we present this copper kettle which is designed to pour out the boiling water very slowly in order to achieve the perfect cup of slow-drip java.

[CHS] made the kettle for his friend [Nate]. The entire process starts off with an arc of flat copper sheet which makes a slightly conical cylinder when curved until the two ends meet. Getting a water tight seal on this seam is imperative and it took four or five tries to reach perfection.

To get the kettle in shape [CHS] improvised a mandrel out of a thin slice of railroad track. After polishing it smooth it goes on the inside of the copper and gives him something to hammer against. We think this step is magic… It’s kind of like the old sculpting adage that you remove everything that isn’t what you’re trying to end up with. The beauty of the piece really pops out as the final curves are hammered into the work.

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Shifting gears on your pig roasting spit

bicycle-gear-pig-roaster

[Tim] and [Jon] have a hankering for some pork product of their own making. Your average residential kitchen is ill-equipped to handle an entire pig, so they got down to business building this pig spit out of old bicycle parts.

The main components in the project are two stands built out of square tube which go on either side of the cooking fire (coal bed?). They include bearings to support a horizontal bar on which a pig carcass is somehow mounted. The whole point of a spit is to turn it while cooking, and that’s where the gear system comes in. The front crank from a bicycle was welded onto the spit, with one pedal still in place. This way if the motorized system breaks down they can still turn the thing by hand.

The crank connects to the cogs with one chain, while the other chain connects the cogs to a windshield wiper motor. When connected to the specified 12V it turns around 6 rpm; close but a bit too fast. After some trial and error they found a 5V supply turns it at the optimal 2 rpm.

We wonder if you can put a whole pig in a meat smoker?

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The most advanced microwave you’ll ever own

raspberry-pi-microwave

Voice activation, one-touch cooking, web controls, cooking settings based on UPC… have you ever seen a microwave with all of these features? We sure haven’t. We thought it was nice that ours have a reheat button with three different settings. But holy crap, what if you could actually program your microwave to the exact settings of your choice? You can, if you let a Raspberry Pi do the cooking.

This hack run deep and results in a final product with a high WAF. Nathan started by taking apart his old microwave. He took pictures of the flexible sheets that make up the control button matrix in order to reverse engineer their design. This led him to etch his own circuit board to hook the inputs up to a Raspberry Pi board and take command of all the appliance’s other hardware. Because it also drives the seven segment display you’ll never see the wrong time on this appliance again. It’s set based on NTP.

We mentioned you can tweak settings for a specific food. The best way of doing this is shown in the demo video. The web interface is used to program the settings. Recalling them is as simple as using the barcode reader to scan the UPC. Amazing.

Now you can keep that old microwave working, rather than just scraping it for parts.

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