How Much Of A Battery Pack Does Your Electric Car Need?

December 25, 2017 by Jenny List 143 Comments

[Elon Musk] recently staged one of his characteristic high-profile product launches, at which he unveiled a new Tesla electric semi-truck. It was long on promise and short on battery pack weight figures, so of course [Real Engineering] smelled a rat. His video investigating the issue is below the break, but it’s not the link that caught our eye for this article. As part of the investigation he also created an online calculator to estimate the battery size required for a given performance on any electric vehicle.

It’s not perfectly intuitive, for example it uses SI units rather than real-world ones so for comparison with usual automotive figures a little mental conversion is needed from kilometres and hours to metres and seconds if you’re a metric user, and miles if you use Imperial-derived units. But still it’s a fascinating tool to play with if you have an interest in designing electric cars or conversions, as you can tweak the figures for your chosen vehicle indefinitely to find the bad news for your battery pack cost.

It’s very interesting from a technical standpoint to see a credible attempt at an electric truck, and we hope that the existing truck manufacturers will show us more realistic prototypes of their own. But we can’t help thinking that the overall efficiency of electric long-distance trucking could be improved hugely were they to make a truck capable of hauling more than one trailer at once. Any safety issues could be offset by giving these super-trucks their own highways, and with such dedicated infrastructure the power could be supplied from roadside cables rather than heavy batteries. In such circumstances these long trains of electrically hauled containers could be rather successful, perhaps we might call them railroads.

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Camping In A…. Corolla?

December 9, 2017 by James Hobson 72 Comments

A weekend away camping in the wilds can do wonders for one’s sanity, and the joy of spending it in a recently converted camping vehicle adds to the delight. In a twist on the conventional camper, redditor [Gongfucius] and his wife have converted their 2005 Toyota Corolla into the perfect getaway vehicle for two.

To make enough room, the rear seating had to go, and removing it was deceptively easy. [Gongfucius] was able to build and fit a platform peppered with storage hatches that could snap into place and cover the trunk and backseat — covering it with felt for added comfort. A mattress was cut to size out of five inch memory foam and his wife sewed fitted coverings to them. More storage nooks in the trunk keep necessities at hand.

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Boxes, Form An Orderly Queue Behind The Armchair!

December 3, 2017 by Jenny List 13 Comments

If you have ever been to a hacker camp, you’ll know the problem of transporting all your stuff to your hackerspace village, or to wherever you’ll be basing yourself for the duration. The car park is always too far away, whatever trolley you’ve brought along is never big enough, and the terrain you have to drag everything over feels more like the Chilkoot Trail than a city sidewalk.

[Jana Marie Hemsing] and [Lucy Fauth] have an effective solution to all your hacker camp transport woes, in the form of a motorized platform designed to carry a storage box. Underneath the platform are a pair of hoverboard motors and their controller board reflashed with a custom firmware.

You might be now looking at it and thinking “So what?”, for a single platform is handy but hardly a comprehensive transport solution. What makes this one impressive though is that it’s not a single board, instead there is a swarm of them for which they appear to have implemented some form of optical following system which is teased through the video we’ve placed below the break and with this Tweet, but not in detail yet in the wiki page. A neat train of platforms follows the lead one, transporting everything with minimum fuss. What can we say, except “We want one too!”. There is some code to be found in a GitHub repository, should you be interested in having a go for yourself.

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Jeep Wrangler Dome Light Mod

December 3, 2017 by James Hobson 42 Comments

If you’re the owner of a Jeep Wrangler, you may have experienced some frustration with the interior dome light. For those not in the know, removing the doors on a warm day or for a bit of fun can lead to a dead battery. This happens because the Wrangler’s light stays on unless the fuse or light are removed, or a custom shutoff switch is added — at the expense of troublesome wiring. You could say it’s a Jeep Thing. [Tim Nummy] offers a solution with minimal modifications.

First off, pop the switch out of the door and set it aside. As a replacement, [Tim Nummy] has managed to salvage a door light switch from an old Mercedes. In addition to the same momentary-off function as the Wrangler’s stock switch, the button on the new one can be pulled out and locked for a secondary off position. Many machines and appliances use this same type of switch in their safety interlocks as a service position. [Tim] didn’t want to cut apart the wiring in the Wrangler in case something goes awry down the line, so for now he has filed down some spade terminals to slot into the Mercedes plug. He’s also 3D printed a nut to nicely secure the new switch in place. Check out his how-to video after the break!

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Hacker Challenge: Sail The Atlantic

November 27, 2017 by Al Williams 26 Comments

We found it incredible that — apparently — no one has sailed an autonomous sailboat across the Atlantic successfully. Compared to an electric craft, sail-powered platforms ought to reduce having to carry batteries or other fuel and enable long-duration missions. The problem, of course, is the sailing conditions in the Atlantic.

The challenge is the focus of the Microtranssat challenge which started in 2010. You can think of the challenge as a race, but not in the conventional sense. Participants can launch their 8 foot (or less) craft any time between July and December, and it doesn’t matter which direction they go. They simply have to cross the Atlantic. If more than one boat makes it, the fastest is the winner.

The current leader is the SailBuoy. This Norwegian entry has made it halfway, but no further. However, it has sailed quite a distance in other places, so perhaps it will make it soon. You can see SailBuoy afloat in the video below.

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Retrotechtacular: How To Repair A Steam Locomotive

November 24, 2017 by Jenny List 41 Comments

Steam locomotives, as a technological product of the 19th century, are not what you would imagine as fragile machines. The engineering involved is not inconsequential, there is little about them that is in any way flimsy. They need to be made in this way, because the huge energy transfer required to move a typical train would destroy lesser construction. It would however be foolish to imagine a locomotive as indestructible, placing that kind of constant strain on even the heaviest of engineering is likely to cause wear, or component failure.

A typical railway company in the steam age would therefore maintain a repair facility in which locomotives would be overhauled on a regular basis, and we are lucky enough to have a 1930s film of one for you today courtesy of the British London Midland and Scottish railway. In it we follow one locomotive from first inspection through complete dismantling, lifting of the frame from the wheels, detaching of the boiler, inspection of parts, replacement, and repair, to final reassembly.

We see steps in detail such as the set-up of a steam engine’s valve gear, and it is impressed upon us how much the factory runs on a tight time schedule. Each activity fits within its own time window, and like a modern car factory all the parts are brought to the locomotive at their allotted times. When the completed locomotive is ready to leave the factory it is taken to the paint shop to emerge almost as a new machine, ready for what seems like a short service life for a locomotive, a mere 130 thousand miles.

The video, which we’ve placed below the break, is a fascinating glimpse into the world of a steam locomotive servicing facility. Most Hackaday readers will never strip down a locomotive, but that does not stop many of them from having some interest in the process. Indeed, keen viewers may wish to compare this film with “A Study in Steel“, another film from the LMS railway showing the construction of a locomotive.

LMS Jubilee class number 5605, “Cyprus”, the featured locomotive in this film, was built in 1935, and eventually scrapped in 1964 as part of the phasing out of steam traction on British railways.

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Your Drone Is Cool, But It’s No Jet Fighter

November 16, 2017 by Jenny List 45 Comments

There are some communities with whom our happy band of hardware hackers share a lot in common, but with whom we don’t often associate. The more workshop-orientated end of the car modification or railway modeler scenes, for instance, or the model aircraft fraternity. Many of these communities exist more for the activity than for the making, some of them dabble with building kits, but among them are a hard core of people who create amazing projects from scratch.

Take [Igor Negoda], for example. Not content with building just any model aircraft, he’s built his own from scratch, to his own design. And if designing for yourself what amounts to a scaled-down jet fighter wasn’t enough, he’s also built his own jet engine to power it. His videos are all in Russian so use YouTube’s subtitle feature if you’re not a Russian speaker, but they’re so good that if you couldn’t access the English translation you’d want to learn the language just to hear his commentary.

The video below the break shows us first a fast-taxi test using a ducted fan, then a full test flight with the jet engine. There is an explanation of the fuel system and the flight control systems, before an impressive flight from what appears to be a former Cold War-era runway. There are a few funny moments such as transporting a large model jet aircraft in a small hatchback car, but the quality of the work in a garage workshop shines through. Suddenly a multirotor doesn’t cut it any more, we want a jet aircraft like [Igor]’s!

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