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From
Farmers Weekly in the UK:
An electrically powered six-wheel-drive ATV that allows wheelchair
users to get actively involved in the countryside has been developed by a
farmer’s son from north Wales. Simon Wragg explains
There are plenty of ATVs on the market but you won’t have seen
anything like this. Sion Pierce, a mechanical engineer from Nantglyn,
near Denbigh, describes his HexHog as a “quad bike on the outside and
wheelchair on the inside”.
Powered by lithium-ion rechargeable batteries, the vehicle has
joystick control, weighs just 275kg and has a range of 8-12 miles,
depending on terrain. That allows it to tackle conditions that
able-bodied persons would find arduous.
Launched at the Naidex Show at the NEC, HexHog uses two 36v motors to
provide independent drive to all six 20x10-10 wheels via low
maintenance gearboxes and driveshafts.
The machine was conceived as part of Mr Pierce’s degree in mechanical
engineering at Harper Adams. “I was inspired having read of a former
student’s brother who felt left out when everyone was helping on the
farm due to limitations of his wheelchair,” says Mr Pierce.
Centipede-like grip is achieved by mounting wheels each side of the
chassis from a pivot (situated between the second and third wheel) from
which front and rear wheels float on trailing arms.
“This patented flexible chassis allows for excellent articulation and ground contact,” explains Mr Pierce.
“HexHog easily copes with 50% slopes. The operator remains
comfortably upright over terrain as the seat adjusts with the position
of each axle via a series of linkages. Forward speed is governed to
8.5mph but can be altered.”
What’s it like to drive?
The demonstrator we tested was smaller than the on-line video
suggested at roughly 1.8m x 1.2m (5ft 9in x 4ft). It’s fitted with an
optional electric retractable seat allowing side-by-side transfer from a
wheelchair and a rally-type bucket seat and four-point harness keeps
the operator secure.
Paddle switches on the armrest alter the seat ride height, allowing
you to place your feet comfortably on the aluminium chequerplate floor. A
car key sends power to the motors and the HexHog is “driven” with a
right hand-mounted joystick.
Pushing the joystick forward releases the brakes in the 36v motors
before moving off. “It’s one of the beauties of the system; if you
aren’t happy at any time crossing terrain you just let go of the
joystick and HexHog comes to a halt.”
Off-road
The sensitivity of the joystick control can be adapted to suit
individual users. On all surfaces HexHog can easily leave able-bodied
persons behind but especially where ground conditions are damp, wet,
slippery or undulating under foot.
According to wheelchair user Vincent Ross (pictured), whose company
will assist in the HexHog’s manufacture, it’s a major step forward. “You
feel in control all the time. There’s no sudden sensation of tipping
forward or pitching as it moves over the ground. Once you’re used to it
you get a strange feeling of security,” he explained.
Range is up to 12 miles, with a display on the left-hand armrest
showing battery life. A recharge from a normal 13A socket takes a little
over two hours.
It’s made from off-the-shelf components, so most vehicle electrical engineers would be able to maintain it.
It’s also nil rated for VAT, can be driven on the highway on a car
licence (it has ATV-style road lights) and can be transported on a
lightweight single axle trailer without the need to take a statutory
trailer test. A remote control unit for unloading is available.
Development
It’s taken well over a year of development – aided by an investment
from an off-road vehicle component manufacturer Safety Devices to get
HexHog to production, explained Mr Pierce. “If it gives wheelchair users
a chance to be involved in the countryside then I’ve achieved my
objective.”
Prices start from £18,000. “On and off road mobility scooters cost
around £12,000-20,000 and many are severely limited once outside the
urban environment,” explained Mr Pierce, who will manufacture the HexHog
with adaptive equipment company Da Vinci Mobility of Liverpool.
