The Electric Vehicles Of Electromagnetic Field: The Ottermobile And The Ottercar

If you’ve followed these pages over the last few weeks, you’ll have seen an occasional series of posts featuring the comedic electric vehicle creations of the British Hacky Racers series, which will make their debut at the forthcoming Electromagnetic Field hacker camp. So far these intrepid electro-racers have come largely from the UK hackerspace and Robot Wars communities, but it was inevitable that before too long there would arrive some competition from further afield.

[Jan Henrik] and [Niklas Fauth] are a pair of prolific German hardware hackers whose work you may have seen from time to time in other fields. When they heard about Hacky Racers with barely two weeks until they were due to set off for England for EMF, they knew they had to move fast. The Ottermobile and the Ottercar are the fruits of their labours, and for vehicles knocked together in only two or three days they show an impressive degree of sophistication.

In both cases the power comes courtesy of hoverboard wheels with integrated motors. If you cast your mind back to last year’s SHA Camp in the Netherlands, our coverage had a picture of them on a motorised armchair, so this is a drive system with which they have extensive experience. The Ottercar is based upon a lengthened Kettler kids’ tricycle with the larger variant of the hoverboard motors, and unusually it sports three-wheel drive. Control for the rear pair comes from a hoverboard controller with custom firmware, while the front is supplied by a custom board. The Ottermobile meanwhile is a converted Bobby Car, with hoverboard drive. It’s an existing build that has been brought up to the Hacky Racer rules, and looks as though it could be one of the smaller Hacky Racers.

At the time of writing there is still just about enough time to create a Hacky Racer for Electromagnetic Field. Following the example set from Germany, it’s possible that the hoverboard route could be one of the simplest ways to do it.

The Electric Vehicles Of Electromagnetic FIeld: The Selby

A couple of weekends ago on a farm in rural England with a cider orchard and a very good line in free-range pork sausages, there was the first get-together of the nascent British Hacky Racers series of competitions for comedic small electric vehicles. At the event, [Mark Mellors] shot a set of video interviews with each of the attendees asking them to describe their vehicles in detail, and we’d like to present the first of them here.

The Selby is unique among all the Hacky Racers in being a six-wheeler. It’s the creation of [Michael West] of MK Makerspace, and it bears a curious resemblance to a pair of PowaKaddy¬†golf buggies grafted together. The resulting vehicle has four driven wheels and two steering wheels, and though it is hardly a speedy machine this extra drive gives it what is probably the most hefty pulling power of all the contestants. In the video below it appears without bodywork, but we are told that something impressive will sit upon it when it appears at Electromagnetic Field.

View of motors fed with 24 V driving the rear wheels

I should own up, that the Selby is a familiar to Hackaday, as I’m also an MK Makerspace member. I’ve seen it progress from two worn-out golf trolleys to its current state, and seen first hand some of the engineering challenges that has presented. The PowaKaddy buggies of that vintage are extremely well-engineered, with a Curtis controller that is still comfortably within spec even when driving four motors instead of two. Unusually for a Hacky Racer the power comes from a pair of huge lead-acid batteries, as these were the power source supplied with the PowaKaddy from new and it made little sense to change them. Gearing is fixed at golf-course speeds, and braking comes from a pair of brakes fitted on the motors. The motors themselves are simple DC affairs, with significant weatherproofing.

Cutting and shutting the two PowaKaddys was straightforward enough, but introduced a warp to the chassis that was solved by your Hackaday scribe hanging on the end of a lever formed from a long piece of 4-by-2 while [Mike] and friends stood on the other end of the Selby.

As a driving experience it’s exciting enough but lacks the speed of some of its competitors. Where it really comes into its own though is off-road, as the multi-wheel drive and broad treaded tyres power it across mud and offer powersliding opportunities on wet grass.

We’ve covered a couple of Hacky Racers so far in our mini-series on the Electric Vehicles of Electromagnetic Field, and we’ll bring you a few more before the event. Meanwhile feast your eyes on a Sinclair C5, and an Austin 7 inspired mobility scooter conversion.

Continue reading “The Electric Vehicles Of Electromagnetic FIeld: The Selby”

The Electric Vehicles Of Electromagnetic Field: The Dustbin 7

We’re producing an occasional series following some of the miniature electric vehicle builds currently underway at a feverish pace to be ready for the upcoming Electromagnetic Field hacker camp in the UK. Today we’re going down to Somerset, where [Rory] has produced a very serviceable machine he calls the Dustbin 7.

The Hacky Racers series stipulates a ¬£500 budget along with a few rules covering vehicle safety and dimensions, so he had to pick his components carefully to allow enough cash for the pile of LiPo batteries he’d have to buy new in the absence of a convenient surplus source. The motor he picked was a 2kW brushless scooter motor, and that he mated to a 48V e-bike controller

Running gear came from a surplus school project race car but looks suspiciously similar to the wheels you’d see on a typical electric wheelchair. His chassis is welded box section steel, and the bodywork has a classic car feel to it as he comes from a family of Triumph owners. The name “Dustbin 7” comes from the affectionate nickname for the popular pre-war British Austin 7 people’s car.

In use, as you can see below it appears to have a fair turn of speed without displaying too alarming a handling characteristic. If this is the standard of vehicles in the competition then we can imagine that racing will be an exciting spectacle!

For more EMF electric vehicle tomfoolery, take a look at this modified Sinclair C5.

Continue reading “The Electric Vehicles Of Electromagnetic Field: The Dustbin 7”

The Electric Vehicles Of EMF Camp: A Sinclair C5, (Almost) As It Should Have Been

Most Hackaday readers will have heard of [Clive Sinclair], the British inventor and serial entrepreneur whose name appeared on some of the most fondly-recalled 8-bit home computers. If you aren’t either a Sinclair enthusiast or a Brit of a Certain Age though, you may not also be aware that he dabbled for a while in the world of electric vehicles. In early 1985 he launched the C5, a sleek three-wheeler designed to take advantage of new laws governing electrically assisted bicycles.

The C5 was a commercial failure because it placed the rider in a vulnerable position almost at road level, but in the decades since its launch it has become something of a cult item. [Rob] fell for the C5 when he had a ride in one belonging to a friend, and decided he had to have one of his own. The story of his upgrading it and the mishaps that befell it along the way are the subject of his most recent blog post, and it’s not a tale that’s over by any means.

The C5 was flawed not only in its riding position, the trademark Sinclair economy in manufacture manifested itself in a minimalist motor drive to one rear wheel only, and a front wheel braking system that saw bicycle calipers unleashed on a plastic wheel rim. The latter was sorted with an upgrade to a disc brake, but the former required a bit more work. A first-generation motor and gearbox had an unusual plywood housing, and the C5 even made it peripherally into our review of EMF Camp 2016, but it didn’t quite have the power to start the machine without pedaling. Something with more grunt was called for, and it came in the form of a better gearbox which once fitted allowed the machine to power its way to the Tindie Cambridge meetup back in April. Your scribe had a ride, but all was not well. After a hard manual pedal back across Cambridge to the Makespace it was revealed that the much-vaunted Lotus chassis had lived up to the Sinclair reputation for under-engineering, and bent. Repairs are under way for the upcoming EMF Camp 2018, where we hope we’ll even see it entering the Hacky Racers competition.

The Electric Vehicles Of EMF Camp

There is joy in the hearts of British and European hardware and software hackers and makers, for this is an EMF Camp year. Every couple of years, our community comes together for three summer days in a field somewhere, and thanks to a huge amount of work from its organizers and a ton of volunteers, enjoys an entertaining, stimulating, and engrossing hacker camp.

One of the features of a really good hacker camp are the electric vehicles. Not full-on electric cars, but personal camp transport. Because only the technically inept walk, right? From Hitchin’s Big Hak to TOG’s duck, with an assortment of motorized armchairs and beer crates thrown in, these allow the full creativity of the hardware community free rein through the medium of overdriven motors and cheap Chinese motor controllers.

This year at EMF Camp there will be an added dimension that should bring out a new wave of vehicles, there will be a Hacky Racers event. Novelty electric vehicles will compete for on-track glory, will parade around the camp, and will no doubt also sometimes release magic smoke. There is still plenty of time to enter, so if you’re going to EMF, get building!

We have an interest in these little electric vehicles, not least because there may well be a Hackaday-branded machine on the tarmac. We’d like to feature some of them over the weeks running up to the event, so if you are building one and have a write-up handy, please tell us about it in the comments. Charge your batteries, and we’ll see you there!

Header image: [Mark Mellors], with permission.