Desert skater

  • Kotzé demonstrates how he skates around subjects to fi lm his smooth off-road tracking shots. He made a pocket movie, using his cellphone, for CNN"â„¢s Go Green Web site about the transition from 4x4 vehicles to the environmentally friendly Bunduboot. Picture by Theuns Kotze
  • Kotzé puts on his Bunduboots and heads into the desert daily for 10-15 km jaunts, just because he can. Image credit: Theuns Kotze
Date:27 January 2011 Tags:,

Bundu-bashing filmmaker develops ultimate off-road filming platform.

There’s something strangely satisfying about a desert. Insulated from the sensory overload that characterises life in the 21st century, its awe-inspiring vistas, big blue skies and eerie silences act as a balm for the human psyche. At least, that’s the way Namibia-based filmmaker Sheldon Kotzé sees it. He’s devoted much of his career to exploring his home turf and documenting the desert’s natural beauty, revelling in the freedom that comes with traversing its vast, pristine expanses.

Although he’s quite happy to embrace the conventional approach when working on documentaries, art films and similar commissions, his own projects are an entirely different ball game, with infinitely adjustable “rules of play”. He explains: “I like using a new style for each film that I make.” Not surprisingly, this strategy requires a fair bit of lateral thinking – especially when putting together his trademark low-budget productions.

Fortunately, Kotzé had a can-do father who taught him the ropes from an early age. “My dad was an amateur filmmaker, and I assisted him on shoots as a boy. He was always building things to make it easier to film his projects. Thanks to his influence, I’ve been converting scrap materials into useful stuff for years.”

Read more about radical personal aircraft that go beyond the flying car in the February 2010 issue of Popular Mechanics – on sale on 24 January.

When it comes to filming, Kotzé has one golden rule: there must be plenty of movement. “Moving, in my opinion, is what gives your footage class as well as depth,” he says. “I also find tripod-mounted shots boring… they make the footage too static for my liking. As far as I’m concerned, if you’re going to take this approach to filming, you may as well just take a stills shot.”

His quest to capture the perfect off-road tracking shot began 10 years ago while filming on top of Bloedkoppie, in the Namib desert, one of the Namibia’s acclaimed tourist destinations. It was a disaster, the hill’s uneven granite surface scuppering his efforts time and again. Looking at the shaky footage from the comfort of his studio afterwards, Kotzé realised he needed to do some serious brainstorming. Then, seemingly from nowhere, he dredged up a childhood memory of the smooth sensation of rollerskating. “I realised that if I was wearing skates, I could easily perform smooth circles around actors to get the movement I wanted.”

Kotzé had no intention of using commercially available in-line skates, having decided they were not sufficiently robust for his needs. Also, their wheels were too far apart to permit the precise manoeuvres he required. He started by cobbling together three sets of standard in-line skate boots to create one pair, extending their height by 15 cm to provide better support for his ankles. Then, because he wanted his skates to be virtually indestructible, he fabricated the frames from sturdy, 6 mm-thick T6 (aircraft grade) aluminium. They had to be over-engineered, he explains, because he intended to mount a camera on each skate and shoot “really cool” low-action footage. Next, he mounted one wheel under the heel and the other under the ball of each foot, enabling him to perform sharp turns, execute fast “power stops” and even skate backwards when necessary.

After much unsuccessful experimentation with 200 mm wheelchair wheels (unable to inflate them to the high pressures required, he rapidly wore them out), he finally had a lucky break when mountain boarding (off- road skateboarding) came on the scene. “ Their wheels were ideal for my purposes,” says Kotzé. “Not only could they be pumped up to 5 bar, but they also came in various tread options, so all I had to do was find the right one for my purpose.”

Having dubbed his invention “Bunduboots”, his next logical step was to locate a suitable motor. He started out by fitting a small two-stroke Weed Eater engine with a spindle drive, attaching it to the left skate along with its fuel tank. Although it worked, Kotzé discovered a number of drawbacks. Aside from being extremely loud and (thanks to the fuel tank) distinctly dangerous, it was heavy – bad news for balance and manoeuvrability – and impossible to reverse. It was also a pain to start, messy and smoked… well, like a two-stroke.

Frustrated, he then tried a 3 kW electric motor from a model aircraft – and hit the jackpot. Compact and relatively quiet, it produced loads of torque and had only one moving part, which made it simple to install. Using the engine housing to directly drive both wheels on one skate (in other words, the armature remained static), he coated it with the same material used to line bakkie loadbeds to achieve the required traction.

The old throttle cable was dumped in favour of a wireless controller designed for radio-controlled model cars. This allows him to set the motor’s timing, throttle response and regenerative braking, to mention just a few of its compelling features.

Although a lightweight pack of lithium polymer batteries would be ideal, their price tag is way out of Kotzé’s league, so he’s settled for two 12V 7Ah electric gate batteries connected in series, wearing them on a belt around his waist. “I’m trying to limit myself to 10 kg; anything heavier than that would be too uncomfortable to carry,” he says. “. ese batteries are not ideal, but they didn’t cost much, and they work well enough for me to conduct proper tests on the skates while I learn about the relationship between watts, amps and volts!”

Although the battery configuration might be a work in progress, Kotzé knows one thing for sure: his Bunduboots are wicked! “I have no idea what their top speed is because every time I get to about 45 km/h, I chicken out. In fact, I’ve never flattened the throttle. All I know is that I definitely would not fit these to my 10-year-old with the engine attached!”

Because he alternates between using the motor and skating the old-fashioned way, as well as constantly varying his speed, Kotzé has no idea what range his current batteries can deliver, explaining: “When the batteries run flat, I just keep on skating.” Meanwhile, his Bunduboots have not only facilitated Kotzé’s a radically different approach to filming, but are hlp-ing to change his client base. He also makes desert-skating films in the surfing genre for skating enthusiasts.

Interestingly, the electric motor not only makes the Bunduboots environmentally friendly to a fault, but their small footprint also allows him to traverse narrow game trails with ease. As Kotzé tells it, “I can go wherever a mountain bike can go.” He heads into the desert every day for 10-15 km jaunts – just because he can – and has got into the habit of “skate-crashing” cycling or road running events. Because the roads are closed and the route is protected by organisers, he’s assured of a fun, stress-free ride.

“Anyone who knows what they’re doing and is looking for a new, extreme experience should really consider the Bunduboot,” says Kotzé. “I can’t wait for someone to make a better knock-up of my invention. I’ll be the first in line to buy one!”

To watch Sheldon Kotzé testing out his electric-powered Bunduboots, click here

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