frame of the vehicle staying level and the wheels left to accommodate. So Simon literally started from “the ground up”. “The suspension actually operates a lot differently to a conventional system because the geometry changes… we’ve got all that right. “Riding a quad bike is counter-intuitive; a perfect example is when riding a motorbike you have to lean into a corner but on a quad you have to lean outwards to de-stabalise it. I think we analysed and processed everything we could,” says Simon. “It’s a workplace vehicle. Bigger to accommodate farmers, and to operate essentially in what is a workplace – the farm. It’s been designed for stockiertypes, burly farmers, who get in and out of the vehicle often and will not operate over 10kph without the user clicking in a seatbelt,” adds Simon, all but touching on an immense range of built-in safety features. The time spent on the project – even its smallest parts – is mind-boggling. Simon picks up a bracket he designed that has had 400 hours put into it purely from a suspension geometry perspective, not to mention the multiple 3D printing of prototype after prototype before casting stages. It’s here where the quality of the parts was greatly helped by Unitec’s Projet 3500 HDMAX 3D printer, allowing component prototype parts to be designed, cheaply produced, and then tested before the costly casting process. It allowed him to get it right before 16 October 2016 The investment in 3D printing technology at Unitec’s Mt Albert Campus sees it now offer two 3D printing machines so others can, like Simon Hartley, turn their ideas into reality through a cost-effective medium whether prototyping, 3D modelling and more. The Campus offers high tech and diverse 3D printing technology solutions and is open to the public. commissioning the high-end working metal part. The portable quad bike is electro-hub driven, and there aren’t too many books out there on the subject. “We’re pioneering a lot of this technology… and essentially what we’ve ended up with is a very large remote control car, and we do actually have autonomous functionality we are developing for it as well,” he says. The project is the culmination of massive amounts of spread sheets, computer modelling, virtual prototyping, 3D printing, component relationship analysis and more, with compromises made to produce solutions but always with the safety factor at front of mind. “The end foot print is 30% wider and 40% longer than a standard quad bike,” he explains, with portability a key factor so it can fit on a standard ute. But it also had to meet some of the requirements of principle sponsors such as Land Corp, who wanted the bike to fit the width of standard quad bike tracks. The design of the roll cage meets Schedule J motorsport standards which is the same that is used for Formula 1 and the V8 Supercars. “Best practice solutions were used in material selections and processes so you can imagine the extents I’ve gone to… things like ratio of the tube used in the cage, all the bend radiuses are actually specified that they need to be a certain ratio to the diameter of the tube.” Something he learnt in the revision ‘3’ stage of the project. Functionality, being a work vehicle, also had to be factored. “It’s got a tray on the back big enough to hold a pallet or four hay bales, and the drive train design needed to be able to climb a certain gradient… you need a lot of torque to climb a 45 degree gradient. It’s been over-engineered for sure,” he laughs. “At the end of the day, this vehicle will ‘scream’ at you before you roll over,” but it goes deeper than that, with user behaviour considered and conditioned via design. Every motor, one on each wheel, has its own motor controller. The hydrogen cell that powers the vehicle is at its core. Of course, it had to be a hydrogen cell, underpinned by the philosophy of, “why build a combustion engine quad bike? Let’s aim for the future”. It fits with clean, green New Zealand as does its plug-in charge capabilities. The vehicle is due to be showcased in just over a month, and Simon is in the process of piecing all the bits together; all that hard work on single components and all that brainstorming to incorporate best practice will come together in front of his eyes. For Simon it has been a mammoth task but for the quad bike industry it could also be a monumental achievement. If it saves one life, it’s 7,500 hours well spent in Simon’s books. I couldn’t help but feel as I walked out of his shed and closed the door on the interview, how apt it would be, just next to his shed, that lemon tree. EN K I W I I N N O VAT I O N Turn your ideas into reality 3D PRINTING NOW AVAILABLE AT UNITEC Construction / Engineering / Architecture / Design Contact Lily Guo copy3D@unitec.ac.nz / 021 990 008 EN115
EN-Oct16
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