How Ukrainians modify civilian drones for military use

IN FEBRUARY 2022, four days after Russia's invasion of Ukraine, a man who goes by the pseudonym "Swat", and who lives in Kyiv, switched on a 3D printer in his garage and began to make plastic tailfins. The idea was to attach them to hand grenades, turning them into miniature bombs that can be dropped from drones.

A year on, Swat (whose name means "go-between" in Ukrainian) helps to run a network called Druk ("Printing") Army, which co-ordinates the output of about 300 3D-printers across the country. A similar network run by a man in Latvia, Swat says, has about 150 collaborators. Following a trail blazed by the likes of Hizbullah and Islamic State, such networks operate an underground manufacturing service, funded mostly by donations, that specialises in converting civilian drones designed for hobbyists, filmmakers and farmers into lethal weapons of war.

The machines tend not to last long once they reach the battlefield. Russian jamming causes many crashes, says a Ukrainian soldier with the call-sign "Bilyy", who flies drones not far from the Russian-occupied city of Donetsk. He routinely loses a couple of machines a day, as do his comrades.

Yet the role of drones in the defence of Ukraine is growing. A Ukrainian colonel in Kyiv, speaking on condition of anonymity, says that, counting their role as reconnaissance machines for artillery, the flying robots now directly or indirectly play a part in more than 70% of Russian casualties. The hacked-together drones tend to be cheaper, and in some cases more effective, than some purpose-designed military machines. The result, says the colonel, is a "new level of war".

March of the makers

The work itself combines ingenuity with frugality. One early technical hurdle was devising a way to allow civilian drones to carry and release bombs. Hobbyists worked out a clever solution by connecting a 3D-printed clamp to an electric motor. The motor is connected to a photo-receptive sensor, which is positioned, in turn, under a light that comes as standard on many consumer drones. (The lights are intended to allow flying at night, and to make drones more visible). When an operator turns the light on, the motor turns, the gripper opens and the payload drops away. "Mag", a young man from Kyiv who has made around 2,000 of these gizmos, says each costs him about $10.

Once a grenade has been dropped, it has to be persuaded to explode. In the years after Russia's seizure of chunks of eastern Ukraine in 2014, hand grenades were squeezed into glass jars that would hold their handles closed. When dropped, the glass would shatter, releasing the handle and detonating the grenade. The drawback, says Bilyy, the drone operator, is that glass is heavy, and does not always break.

These days grenade handles are held in place with a ring of plastic printed in shapes designed to snap even when landing on soft ground. For grenades designed to be fired from a launcher, rather than thrown by hand, the standard fuse is replaced with a 3D-printed tip that holds a nail. Impact pushes the nail into the grenade's detonator, causing it to explode.

Engineers describe the work as exciting. Once a design is crafted, feedback from users comes quickly. Many of the best creations are distributed to other workshops by organisers like Swat. He points to a computer file that instructs 3D printers to make one particularly deadly object. A plastic encasement that holds ball bearings, it fits around an anti-tank mine, turning it into an anti-personnel weapon that can be dropped from bigger drones.

Some of the work involves augmenting the drones themselves, rather than simply fashioning clever payloads for them to carry. A workshop in Kyiv that calls itself Eyes of Army specialises in turning eight-rotor drones designed for crop-dusting into what a member calls "heavy" bombers. The machines carry four Soviet-era mortar rounds. Each shell weighs 3kg and can, if aimed properly, destroy a tank.

The trick is getting close enough. The cropdusters are loud enough to be heard half a kilometre away, so the team installs quieter transmission systems and rotors. An infrared sensor is also added, as are longer-range radios made by Dragon Link, an American firm.

The Eyes of Army crew spends part of its time at the front, flying combat missions at night with the permission of Ukrainian commanders. Enough donations pile up for the team to now and then produce, at a cost of about $35,000, a full attack package for other civilian warriors. Besides the modified drone, this includes an off-road vehicle upgraded with light armour, a control computer with goggles, and multiple battery packs to allow the drone to fly several sorties in quick succession.

Russia flies drones of its own, which Ukrainian commanders are keen to knock out. In one Ukrainian city a rocketry hobbyist nicknamed "Rocketrin" builds, on a workbench at home, his second version of such a system. Dubbed Moskit, it launches from a tube. The next step is to install a camera, which will power an automated guidance system. Unlike most surface-to-air missiles, which are destroyed along with their target, Moskit uses compressed air to eject a net designed to entangle the enemy drone. A parachute saves the interceptor for reuse.

Rocketrin 3D prints most parts. This approach allows for rapid design changes, he says, so it is good for prototyping. But printing a complex component can take ten hours, and demand along the front for drones is "endless". So he plans to set up, probably in a car mechanic's shop, a production line equipped with conventional tools.

All of this improvisation saves money. Eyes of Army reckons its modified octocopters cost a fifth of what an imported military drone with similar capabilities might cost. In another workshop elsewhere in Ukraine, a team of 30 volunteers is cutting carbon fibre with lasers to produce kamikaze quadcopters that deliver 1.5kg of explosives to targets up to 8km away. Each UAV 7, as the contraption is called, costs about $450; assembling the (reusable) control console costs about $1,500. The comparison is imperfect, but the Switchblade 300, a kamikaze drone with a similar payload and range that is manufactured by AeroVironment, an American firm, is reported to cost roughly $6,000 a pop.

Ukrainian troops fly both machines in the heavily jammed airspace around Bakhmut, an embattled eastern city. Around 50 or so drones, from both sides, are in the sky at any one point, says an official. Operators there tell the workshop's boss, whose pseudonym is Boevsskiy, that the UAV 7 is more resistant to Russian electronic warfare than is the Switchblade 300—though they will not go into the technical details. One advantage is a clever signal repeater, designed with input from troops at the front, that greatly extends the UAV-7's range.

Secrecy is a high priority, lest a Kremlin supporter decide "to take revenge", as Swat of Druk Army notes. He carefully vets volunteers, who must first be recommended by people he knows. He also refrains from putting volunteers in touch with each other. One way to produce military drones discreetly is to do so under the cover of an existing factory that makes civilian goods. Last year the owner of one such factory near Kyiv quietly asked some employees to turn Mavic 3s, a hobbyist quadcopter sold by DJI, a Chinese company, into bombers. Today, 15 of the firm's employees produce roughly 5,000 quadcopter bombers a month, so far without attracting Russian attention.

One weak link, says the firm's owner, is his reliance on electric motors imported, at a cost of $16 each, from China. Like some others in Ukraine, he fears China, which has refused to condemn Russia's invasion, might restrict supply. The company's engineers are therefore developing an electric motor of their own, projected to cost just $5. The design is "primitive", admits the owner. But with attrition rates as high as they are, he says, components need not last long. Businessmen friends defray his costs with monthly donations totalling tens of thousands of dollars.

Outside Ukraine, firms sympathetic to the cause need not be so secretive. Ivan Tolchinsky, the CEO of Atlas Aerospace, a maker of non-military drones based in Riga, says he has looked into mass-producing converted civilian craft for use in the fighting. He gave up after determining that obtaining the required permits would take a year, and make sales to civilians more difficult. He notes, though, that a handful of Atlas engineers, working on their own time, are assisting Ukraine's improvisers with technical drawings and advice. One such engineer, who requested anonymity, says he has sent designs for better radio systems, and helped to calculate how much payload the cobbled-together drones might carry.

The street finds its own use for things

As one Ukrainian serviceman in Kyiv points out, the national culture is fertile ground for homespun engineering. Ukraine's education system emphasises both mathematics and engineering. The same is true in Russia, but the culture in Ukraine, he says, encourages personal initiative in ways that Russia's more authoritarian system does not.

In the West, says Kostyantyn Leonenko of Tolocar, a charity based in Hamburg that aims to foster "innovation by mass collaboration" in Ukraine, tinkering is often a playful pastime—disassembling discarded machines to make cute robot toys, for instance. In Ukraine, a middle-income country, it is a much more pragmatic business. Tolocar teams teach people to insulate homes, replace broken windows, fix plumbing, and make things like electric heating mats and cooking stoves.

A visit to Ostriv, a "maker lab" in Kyiv partly funded by the Kyiv National University of Construction and Architecture, is illuminating. Mr Leonenko and a colleague, on their way to teach bicycle-making in Chernihiv, are installing a computerised milling machine. The warren of rooms already boasts a carpentry shop, a metalworking space and equipment for laser cutting, sewing, and 3D printing. Kos Kuchabskiy, who runs the place, says that its tinkerers have made bulletproof vests, caltrops, medical bags and beds for people displaced by the fighting. For a while, four Ostriv members built suicide drones, before decamping to a workshop that specialises in such things.

Back at headquarters, the colonel in Kyiv thinks this duct-tape-and-baling-wire ecosystem a marvel. Elements of it could be incorporated into the Ukrainian defence ministry's procurement process. Mag, the maker of dropping mechanisms, is already receiving official letters with orders for items, albeit without payment.

Russia's army, for its part, is fielding a growing number of similarly modified commercial drones. But its effort is relatively nascent. It also lacks Ukraine's level of support from civilian techies. As a result, the impact of Russia's makeshift drones has been less striking, experts say. The big question is if that will change.

From The Economist, published under licence. The original content can be found on https://www.economist.com/science-and-technology/2023/05/08/how-ukrainians-modify-civilian-drones-for-military-use