Contender For World’s Most Unsettling Drone?

We’re not sure what FESTO is advertising with their odd flying beach ball. Amongst inspirational music it gently places its translucent appendage over a water bottle and then engulfs it with an unsettling plastic sound. With a high pitched whine it hovers away with its prey and deposits it in the hand of a thirsty business man, perhaps as a misguided nurturing instinct.

Despite discovering a new uncanny valley, the robot is pretty cool. It appears to a be a hybrid airship/helicopter on a small-scale. The balloon either zeros out the weight of the robot or provides slightly more lift. It’s up to the propellers to provide the rest.

We like the carbon fiber truss around the drone. It’s a really slick build with barely an untamed wire. This seems like a much safer design than a quadcopter for indoor flying. If its end effector wasn’t so creepy it would be even cooler. Video after the break.

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Fixing a Toyota Camry Hybrid Battery for Under Ten Dollars

[scoodidabop] is the happy new owner of a pre-owned Toyota Camry hybrid. Well at least he was up until his dashboard lit up like a Christmas tree. He did some Google research to figure out what all of the warning lights meant, but all roads pointed to taking his car into the dealer. After some diagnostics, the Toyota dealer hit [scoodidabop] with some bad news. He needed a new battery for his car, and he was going to have to pay almost $4,500 for it. Unfortunately the car had passed the manufacturer’s mileage warranty, so he was going to have to pay for it out-of-pocket.

[scoodidabop] is an electrician, so he’s obviously no stranger to electrical circuits. He had previously read about faulty Prius batteries, and how a single cell could cause a problem with the whole battery. [scoodidabop] figured it was worth testing this theory on his own battery since replacing a single cell would be much less expensive than buying an entire battery.

He removed the battery from his car, taking extra care not to electrocute himself. The cells were connected together using copper strips, so these were first removed. Then [scoodidabop] tested each cell individually with a volt meter. Every cell read a voltage within the normal range. Next he hooked up each cell to a coil of copper magnet wire. This placed a temporary load on the cell and [scoodidabop] could check the voltage drop to ensure the cells were not bad. Still, every cell tested just fine. So what was the problem?

[scoodidabop] noticed that the copper strips connecting the cells together were very corroded. He thought that perhaps this could be causing the issue. Having nothing to lose, he soaked each and every strip in vinegar. He then wiped down each strip with some steel wool and placed them into a baking soda bath to neutralize the vinegar. After an hour of this, he reassembled the battery and re-installed it into his car.

It was the moment of truth. [scoodidabop] started up his car and waited for the barrage of warning lights. They never came. The car was running perfectly. It turned out that the corroded connectors were preventing the car from being able to draw enough current. Simply cleaning them off with under $10 worth of supplies fixed the whole problem. Hopefully others can learn from this and save some of their own hard-earned money.

Solar powered robot mows your lawn while you chill indoors

solar-powered-lawn-mowing-robot

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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Hybrid rocket engine uses acrylic as fuel

We are fascinated by the hybrid rocket engine which [Ben Krasnow] built and tested in his shop. It is actually using a hollow cylinder of acrylic as the fuel, with gaseous oxygen as an oxidizer. We’re already quite familiar with solid rocket propellant, but this hybrid approach is much different.

When a rocket motor using solid propellant is lit it continues to burn until all of the fuel is consumed. That is not the case with this design. The acrylic is actually burning, but if the flow of oxygen is cut off it will go out and can be ignited later. This also opens up the possibility of adjusting thrust by regulating the pressure of the oxygen feed.

[Ben] milled the test rig in his shop. It’s a fat acrylic rod through which he bored a hole. There are two aluminum plates which complete either end of the chamber. The intake has a fitting for a valve which connects to the oxygen tank. There is a nozzle on the outflow end. Check out the video after the break to see a full description. You’ll also get a look at the toll the combustion heat takes on the rig.

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Fauxrarri is the PPPRS Champion

The Power Racing Series (PPPRS) is an electric vehicle competition with a $500 price ceiling. This is Fauxarri, the 2012 Champion. It was built by members of Sector67, a Madison, WI hackerspace. To our delight, they’ve posted an expose on the how the thing was built.

It should come as no surprise that the guys behind the advance electric racer aren’t doing this sort of thing for the first time. A couple of them were involved in Formula Hybrid Racing at the University of Wisconsin. That experience shows in the custom motor controller built as an Arduino shield. It includes control over acceleration rate, throttle response, and regenerative braking. But you can’t get by on a controller alone. The motors they used are some special electric garden tractor motors to which they added their own water cooling system.

If you want to get a good look at how fast and powerful this thing is head on over to the post about the KC leg of PPPRS (it’s the one towing a second vehicle and still passing the competition by).

Driving your home appliances with hybrid power

This system of hybridizing your home’s electric appliances is an interesting take on solar energy. It focuses on seamlessly switching appliances from the grid to stored solar energy as frequently as possible. There’s a promo video after the break that explains the setup, but here’s the gist of it.

Follow along on the pictograph above. We start on the left with solar panel. This feeds to a charger that tops off a 12V battery. When that battery is full, the charger feeds to the inverter which converts the 12V DC to 110V AC power. This is fed to a pass-through which is in between the appliance (in this a case a lamp) and the wall outlet. The pass-through will switch between mains power coming from the outlet, and the 110 coming from the inverter. The homeowner won’t know, or care, which power source is being used. But sunny months should result in lower energy bills. The real question is how long it takes to cover the cost of the system in saved electricity.

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Testing Lithium cells for use with a hybrid car

[Mikey] got a real deal on some A123 Pouch Cells. These are large Lithium cells that tolerate 100A discharge and 50A recharge currents, with 20 AH of life off of one charge. He’s been doing a bunch of testing to find out if the cells can go into an expandable battery pack and be made for use with hybrid cars.

We just looked in on a battery tester used for solar power car arrays. This is a similar situation except [Mikey] is focusing on the test data, rather than the apparatus. The link above is a collection of his notes from testing. Start reading at the bottom of the page up to get the chronology right. He starts to zero in on the most efficient charging methods. Immediately he’s hit with a big need for cooling as the cells take no time to pass 100 degree Fahrenheit. He continues testing with heat sink and fan, and even brings a thermal imaging camera to help with the design.

[Thanks Chris]