Learn How to Drive in the Sand With This Cool Lego Off-Road Build

It’s the perfect sand driving primer, but in Lego form.

byLewin Day|
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YouTube/Brick Technology
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Proper off-roading is an art that takes time and lots of experience to master. But of all the environments any adventurer can encounter on the trail, sand can be one of the trickiest and most complex. Driving on sand takes the right equipment and the right technique. And while you can learn all the tricks from an off-road driving course, you could also learn the basics with the aid of this incredible Lego video.

YouTube channel Brick Technology has a video that will teach you all you need to know about the engineering and physics behind driving on sand. We've seen the channel run fun experiments before, like designing a car for easy parallel parking. This video, though, it's all about building a Lego vehicle that can best tackle the challenge of driving in soft sand.

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The build starts off with a simple Lego car with a rear-wheel-drive setup. It initially struggles in the soft sand, digging in instead of making forward progress. The first mod is to redistribute weight to the rear, which helps a little. The further addition of wider tires with a larger contact patch works wonders, too.

Next up, we get to learn why locking diffs are important on sand. A regular open differential can only send the same amount of torque to both wheels. Thus, when one wheel is making no contact with the ground and ends up spinning freely, there's almost zero torque going to the other wheel as well. A locking diff solves this, allowing maximum torque to be put down to the ground at whichever wheel has grip.

With some ever-bigger tires and some added ground clearance, the Lego rambler can haul a 1.6-pound payload through the sand without protest. Sadly, upping that to 2.2 pounds stripped the gearing. To fix this, the car gets a ground-up rebuild with four-wheel drive and a remote-controlled diff lock at the rear. With the new drivetrain, it's able to haul 2.2 pounds through the soft slalom course. 

From there, the video ups the challenge substantially. Deep potholes and side slopes make it far more difficult for the humble Lego vehicle to make any forward progress. Upgrades come thick and fast though, in the form of an articulated suspension and a front diff lock, too. The ultimate mod comes in the form of a 6x6 drivetrain swap which remodels the experimental Lego car into the style of a military truck. In its final form, it's able to handle anything the sand tank can throw at it.

The video is a great way to learn about the key factors involved in driving on sand. The lessons are simple. You'll want to expand your contact patch as much as possible to float over the sand, albeit in a real car, you'll achieve this by dropping the tire pressures. You'll also want a rear-biased weight distribution, and you'll want locking diffs if at all possible. Follow these rules, and you'll be less likely to get stuck on your next desert expedition.

Got a tip? Let the author know: lewin@thedrive.com

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