Blatchford: Moon Run Success with MatsuuraHigh Performance Prosthetic Sports FootReleased at: 15:00 05/01/2006 Whatever challenges and issues are thrown at us on a daily basis, business or personal, they must all surely pale into insignificance compared to those confronted by motivational speaker and part-time marathon runner, Chris Moon.
His Challenge. Run 135 miles across sand, rock and scrub in Death Valley, California with temperatures fluctuating between 50oC and zero, climb the 14,800ft Mount Witney, a round trip of 26 miles, and then run back 135 miles to the start. All to be completed within 7 days!
Oh, and by the way, Chris is an amputee who lost his lower right arm and leg in a landmine accident in 1995.
.jpg) Faced with this challenge, just one of many such ‘runs’ that he has completed since his accident, Chris contacted the UK’s leading specialist prosthetic limb manufacturer, Blatchford, Basingstoke, to design a high energy sports foot that could withstand this gruelling “Badwater Ultramarathon”.
With extensive experience in the design and manufacture of prosthetic ‘sports’ feet, designers at Blatchford were well equipped to provide Chris with the solution he needed, as conveyed by designer, Clive Smart. “We knew what bio-mechanical loads go through a foot during use by the average wearer. In consultation with Chris, we put together a foot specification.
 “We combined our initial sketches with a bit of old-fashioned maths, and then went straight onto the CAD to design the virtual parts. Compounding our challenge was the time restraint. We had little over one month to produce the design, which then gave Chris just five days to ‘get acquainted’ with his new foot before starting the Ultramarathon.”
The solution, now marketed as the Mercury Sports Foot, combines active carbon composite heel and toe springs to give a lively yet smooth foot action. These springs, manufactured by Blatchford using highly specialised carbon pre-pregnated lay-ups, are connected independently to a carrier and allow the foot to adapt naturally to slopes and rough ground.
“Produced from high-grade aluminium and titanium, the foot carrier was machined on our 15,000 rpm, Matsuura MC 510VG vertical machining centre, while the titanium fastening pins and ‘leg’ were turned on the ROMI G10 which was also supplied by Matsuura, ROMI’s sole UK distributor. To cushion Chris’s stump from the high impact loads, the carrier also incorporates a vertical shock absorber
 “Because it was a completely new type of foot we weren’t sure it would work until the moment we fitted it to Chris. You can do all the maths beforehand, but until someone walks on the prototype you can never really appreciate how it will feel. It’s rather like developing a new formula one car, only the driver can tell you how it handles.”
And in part, it was this similarity to the motor sport and aerospace businesses that led Blatchford to purchase the machines from Matsuura.
Kevin Byrne, Manufacturing Engineering Team Leader, recalls his experiences back in 1995, “When we first started looking for a machine to produce our range of knee joints, one of the factors, among many others, that we took into consideration was experience within industries such as aerospace and motor sport.
“As with these sectors, we tend to use exotic type materials and are continually looking at new solutions. Our customers too, seek maximum performance with minimal weight from our products. They also expect, and receive, long life with zero failure. The tolerances we machine to, therefore, are extremely tight.
“Clearly, Matsuura is a strong player in these areas with a reputation for quality. For the knee joint application, we eventually decided upon a 15,000rpm Matsuura MAM 500HF horizontal machining centre with an 11-station automatic pallet changer.
“It may surprise many people to know that the annual requirement for prosthetic limbs is 60,000 in the UK alone. We produce many different families of legs, for instance, in differing grades and sizes. With a wide mix of parts, varying annual quantities from 50 to 3,000 and the need to produce short batch production runs, including prototypes, the multi-pallet horizontal was the ideal solution. Everything is made from billets - and all parts come off finished in one hit. Fixturing is simple and inexpensive. We use vice-type fixturing, which is manufactured in-house. With 240 tools available, unmanned running is a possibility enabling us to react quickly to changing requirements - by day or night.
“As an example of the benefits we are obtaining, setting time is now virtually zero as is our WIP and cycle times have been halved. In fact, in the majority of instances, our throughput is such that we finish the parts before we are required to pay for the raw material. With regard to tolerances, an example of the accuracy of the Matsuura is a recent batch of 70 parts that we produced which had a tight limit of +/- 5 microns - all came off to specification.
“With the Matsuura MAM 500HF being filled to capacity, an additional machine was needed in 1999 to satisfy the increasing demand for prototype and development work. The 860 x 400 mm table size, Matsuura MC-510VG vertical machining centre with a 15,000 rpm spindle speed was the natural choice for this role. This gives us the capability to transfer parts from the horizontal as and when required, using the same 3D processes, fixturing, etc. on both machines.
“And it was this machine that enabled us to produce the Mercury Sports Foot in time for Chris Moon’s “Badwater Ultramarathon”. The ROMI G10 was our latest purchase from Matsuura - in January 2001 - and probably the most difficult decision to make out of the three machines. The choice of a 2-axis CNC lathe is extremely wide as is the spread of machine prices. Although we had a limited budget for this project, we needed a machine that could turn the range of exotic materials that we work with - to the close tolerances that our product demands. The ROMI G10 has performed admirably in this respect.”
Basic specification of the ROMI G10 includes a spindle speed of 6,000rpm, bar capacity of 42mm; chuck size of 165mm and turned length of 400mm. The machine supplied to Blatchford was configured with a Fanuc 21iT CNC, chip conveyor, parts catcher, tailstock and tool setter.
Chris Moon completed the Badwater Out & Back at 3.20am on the 1st of August 2001, within the 7 day cut off period. In between the out & back sections of the Ultramarathon, each comprising 5 marathons, he climbed the 14,800ft Mount Witney.
Blatchfords utilise 3 Matsuura machines, including a 32 pallet 5 axis MAM72-35V & a MAM-500HF PC11 eleven pallet horizontal.
 For more information about Blatchfords & their products, please visit www.blatchfords.co.uk
For more information on Matsuura supplied products & services please call 01530 511400 or email sales@matsuura.co.uk
Category: Medical |
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