Designing Compact Gasoline Generator Prototype For Drone Use

July 20, 2019 by Lewin Day 39 Comments

Lithium batteries and brushless motors helped make multirotor drones possible, but batteries only last so long. Liquid fuels have far greater energy densities, but have not been widely applied in these roles. [Tech Ingredients] has been experimenting with a compact gasoline-fueled generator, with the aim to extend drone flight times well beyond what is currently possible with batteries (Youtube link, embedded below).

The build began with a single-cylinder, four stroke engine. However, torque spikes and vibration made things difficult. After some iteration, the design settled on employing two single-cylinder two stroke engines, fitted with a timing belt to keep them 180 degrees out of phase. In combination with a pair of balanced flywheels, this keeps vibration to a minimum. Brushless motors are used as generators, combined with rectifier diodes and capacitors to smooth the voltage output. The generator is intended to be used in parallel with a lithium battery pack in order to ensure the drone always has power available, even in the event of a temporary malfunction.

This is a build with plenty of promise, and we can’t wait to see what kind of flight time can be achieved once the system is finished and flight ready. We’ve seen others experimenting with hybrid drones, too.

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Hybrid Drones Could Have Massively Extended Flight Times

July 19, 2019 by Lewin Day 130 Comments

Multirotor drones truly took off with the availability of lithium polymer batteries, brushless motors, and cheap IMUs. Their performance continues to improve, but their flight time remains relatively short due to the limits of battery technology. [Nicolai Valenti] aims to solve the problem by developing a hybrid generator for drones.

The basic concept consists of a small gasoline engine, connected to a brushless motor employed as a generator. The electricity generated is used to run the main flight motors of the multirotor drone. The high energy density of gasoline helps to offset the added weight of the generator set, and [Nicolai] is aiming to reach a goal of two hours of flight time.

There are many engineering problems to overcome. Engine starting, vibration and rectification are all significant challenges, but [Nicolai] is tackling them and has already commenced flight testing. Experiments are ongoing with 500 W, 1,000 W, and 2,000 W designs, and work is ongoing to optimise the engine and electronics package.

It’s a project that holds the potential to massively expand the range of operation for medium to large multirotors, and should unlock certain capabilities that have thus far been limited by short battery runtimes. Gasoline powered drones aren’t a new idea, but we’ve seen precious little in the hybrid space. We look forward to seeiing how this technology develops. Video after the break.

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Russian Drone Can Lift 142 Phantom 3 Drones

November 28, 2017 by Will Sweatman 58 Comments

Russia has long been known for making large machines. They hold the current record for the largest helicopter ever made – the MiL V12. Same goes for the world’s largest airplane, the Antonov An-225. Largest submarine? Yep, they made that too – the Typhoon class. It would appear they’ve thrown their hat in the drone business as well.

While the SKYF drone is made by a private Russian company, it is one of the largest drones we’ve ever seen. Able to lift 400 pounds (a Phantom 3 weighs 2.8 pounds) and can fly for eight hours, the SKYF drone is a nice piece of aeronautical engineering. Quad-copter style drones provide lift by brute force, and are typically plagued with low lift capacities and short flight times. The SKYF triumphs over these limitations by using gasoline powered engines for lift and electric motors for navigation.

It’s still in the prototype stage and being advertised for use in natural disasters and the agriculture industry. Check out the video in the link above to see the SKYF in action.

What’s the largest drone you’ve seen?

Thanks to [Itay] for the tip!

Repaired Manned Multicopter Flies Without Horrifying Crash

July 28, 2016 by Gerrit Coetzee 81 Comments

[amazingdiyprojects] has been making lots of test flights in his crazy eight propeller gasoline powered danger bucket.

We last covered the project when he had, unfortunately, wrecked the thing in a remote-controlled test flight. He later discovered that the motor’s crankshaft bearings had, well, exploded. The resulting shrapnel destroyed the motor and crashed the drone. He described this failure mode as “concerning”.

Also concerning is the act of stepping into the seat once all the propellers are started up. He tags this as “watch your step or die”. Regardless, he also describes flying in the thing as so incredibly fun that it’s hard to stay out of it; like a mechanical drug. It explains why his channel has been lately dominated by videos of him testing the multicopter. Those videos are found after the break.

The device drinks 0.65-0.7 liters per minute of gasoline, and he’s been going through reserves working out all the bugs. This means everything from just figuring out how to fly it to discovering that the dust from the ground effect tends to clog up the air filters; which causes them to run lean, subsequently burning up sparkplugs. Dangerous, but cool.

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Manned Multicopter Project Undaunted By Crash

February 13, 2016 by Gerrit Coetzee 97 Comments

We have to be impressed by [amazingdiyprojects] who completely totaled their manned multi-copter build, which has been spanning over eight videos. He explained the crash in video number eight and is right back at it, learning from the recent mistakes.

When you get right down to it, this is as dangerous as this seems. However, a giant multicopter is probably the easiest flying machine for a hobbyist to build. It’s an inefficient brute-force approach, but it sure beats trying to build a helicopter from scratch. This machine is a phenomenally un-aerodynamic chair on a frame that has a lot in common with the lunar rover; with engines on it. Simple.

There are a lot of approaches to this. One of the crazier ones is this contraption with a silly amount of electric motors. [amazingdiyprojects] went with eight gasoline engines. We’re really interested in his method for controlling the rpm of each engine and dealing with the non-linearity of the response from a IC engine throttle. Then feeding that all back into what is probably the exact same electronics from a regular diy drone.

Honestly, we’re surprised it worked, and we can’t wait for him to finish it so we can see him zooming around in his danger chair. Videos after the break.

Thanks [jeepman32] for the tip!

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Flaming Jack-o’-lanterns Light Up The Night

October 30, 2014 by Adam Fabio 14 Comments

[misterdob] wanted to spice up his Halloween decor, so he built these flaming concrete jack -o’-lanterns to decorate his walkway. He started with the classic plastic jack-o’-lanterns that trick-or-treaters have been using to collect candy for years. [misterdob] filled the plastic pumpkins halfway with concrete mix, then dropped in metal coffee cans. He then filled the pumpkins up to the top with concrete, shaking them up a bit to avoid air pockets.

Once the concrete had set, [misterdob] cut away the plastic revealing nearly perfect concrete duplicates. He used acid stain to color his creations – though it looks like he missed a spot or two.

We have to disagree with [misterdob’s] choice of fuels. In fact, we think he was out of his gourd when he picked gasoline for his flaming pumpkins. Seriously though, gasoline is a horrible choice for a fire pot like this for a multitude of reasons. Gas has a particularly foul odor and its fumes are explosive. If a Halloween prankster were to try kicking one of the pumpkins over, not only would they have a broken foot, they’d also be covered in burning gas.

Thankfully, the folks on [misterdob’s] Reddit thread had better fuel suggestions – citronella torch cans with lamp oil and wicks, kerosene, or gel fuel would be better suited for these hot pumpkins.

If you still don’t believe how dangerous gas and its fumes can be, check out this video of a bonfire gone wrong (language warning).

Boil Off Some White Gas In The Back Yard

December 9, 2013 by Adam Fabio 56 Comments

Gas-still

[S Heath] is a Coleman lantern collector. Coleman lanterns can run from a variety of fuels, however they seem to run best with white gas, or Coleman fuel. Store bought Coleman fuel can cost upwards of $10USD/gallon. To keep the prices down, [S Heath] has created a still in his back yard to purify pump gas. We just want to take a second to say that this is not only one of those hacks that we wouldn’t want you to try at home, it’s also one that we wouldn’t try at home ourselves. Heating gasoline up past 120 degrees Celsius in a (mostly) closed container sounds like a recipe for disaster. [S Heath] has pulled it off though.

The still is a relatively standard setup. An electric hot plate is used to heat a metal tank. A column filled with broken glass (increased surface area for reflux) rises out of the tank. The vaporized liquid that does make it to the top of the column travels through a condenser – a pipe cooled with a water jacket. The purified gas then drips out for collection. The heart the system is a PID controller. A K-type thermocouple enters the still at the top of the reflux column. This thermocouple gives feedback to a PID controller at the Still’s control panel. The controller keeps the system at a set temperature, ensuring consistent operation. From 4000 mL of ethanol free pump gas, [S Heath] was able to generate 3100 mL of purified gas, and 500 mL of useless “dregs”. The missing 400 mL is mostly butane dissolved in the pump gas, which is expelled as fumes during the distillation process.

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