The low-tech Flexipump is easy and intuitive to operate.
The low-tech Flexipump is easy and intuitive to operate.
Using Solid Edge software, the designer was able to refine the design and optimise it for injection moulding.
Using Solid Edge software, the designer was able to refine the design and optimise it for injection moulding.
The Flexipump line assembly. The final product weighs 2.5 kg compared to an original weight of 4.5 kg.
The Flexipump line assembly. The final product weighs 2.5 kg compared to an original weight of 4.5 kg.

With an initial design which resembled an oversized bicycle pump with a piston and two valves, David Hutton created the Flexipump, a highly productive irrigation pump for farmers in the developing world. Specialised software later helped him refine and optimise his design.

David Hutton is now managing director of Hutton Technologies, a social enterprise committed to providing innovative, low-cost, low-maintenance solutions for people in the developing world. His Flexipump design came from an idea he had when he was just 13. It was a simple water pump that would make irrigation easier for farmers in the developing world, and this became the topic of his final year project as an engineering student at the University of Bath.

Safe and easy
Hutton knew that, aside from the physical effort of carrying water over a long distance and the time spent on multiple journeys, farmers in developing countries who collect water from rivers and lakes often face the additional hazard of crocodiles, which tend to congregate in areas where people regularly draw water. Hutton wanted to create a pump that would not only cut the time spent on irrigation, but one that would be safe and easy to use as well.

He had also read research undertaken by the University of Cambridge in the UK which showed that worldwide there are 500 million small holder farmers supporting a total of 2 billion people. “That’s almost one-third of the world population,” he noted. “Helping these farmers boost crop yields and increase their income could make a massive difference to many lives. Yet it seems that only about 5% of engineers work on projects or products that specifically benefit people living in the developing world.”

Hutton’s efforts to make a difference to those farmers led to his Flexipump design but one of the most critical parts of that design was that the pump must be easy to maintain. “A 2001 study estimated that 36% of pumps in the developing world were broken, and remained that way

because farmers had no access to spare parts and lacked the specialist knowledge needed to mend them. What’s astonishing is that, in the developed world, such a situation would be widely regarded as a significant failure.”

Hutton’s original design was similar to an oversized bicycle pump, with a piston and two valves, one pointing forward as an inlet, and one higher up as the outlet. He knew that this simple design would help the farmers with maintenance. “Farmers are familiar with how bicycle pumps work, therefore they would already know how to operate and repair the Flexipump.” he said.

Specialist software
As a student, Hutton had access to Solid Edge software from product lifecycle management (PLM) specialist Siemens Digital Industries Software. Using Solid Edge, he created his first 3D design for the pump. “I found that using Solid Edge was extremely helpful in terms of spatial understanding,” he explained. “I began with certain constraints and then I could select parts and work out how to assemble everything into a small space. Solid Edge was great. The trouble was that I was nowhere near finished with the design of the Flexipump when I completed my degree course.”

Realising he was on to something worth following through, Hutton requested permission to continue using university facilities after he had graduated in 2011. That helped him to progress the design to the point where he could go to Zambia and conduct extensive field tests. Operating from the back of a car, he set up a mobile workshop and made 25 pumps in three different versions for testing by local farmers.

Hutton found that while he was doing his tests, it was quite difficult to obtain honest feedback. “I discovered that criticism was considered rather impolite in Zambian culture. In some cases, for example, the pumps I had given out got clogged with stones and stopped working, but I did not always find out about this. In the end I learned a huge amount from observing the farmers and through using the pump myself. It was clear that I had to bulk-up the design to make it more robust and very easy to use.”

Returning to the UK, Hutton had a market and a potential order, but found himself without computer-aided design, a state he describes as “CADless” until he downloaded a free trial of Solid Edge. At the time, he was working with Ken Symonds, a freelance parts’ designer engaged to help redesign some of the Flexipump parts and make them suitable for injection moulding. “Using Solid Edge again reminded me how great it is,” explains Hutton. “I was on a tight budget and was dreading the end of my free trial when I found out from Ken that SolidEdge was also available on a monthly subscription. This was clearly the answer for me, and I registered with Siemens Digital Industries Software partner OnePLM.”

Using Solid Edge, Hutton had the means to refine the design and optimise it for injection moulding. “I also bought a cheap 3D printer which I can 100% recommend,” he said. “It made a massive difference to the process of getting parts ready for manufacture.”

Commercial launch
The Flexipump went into production in Italy in the early summer of 2014, as Hutton took the first bulk order and conducted further tests in Malawi and Zambia. “Without the Solid Edge subscription, I would have been pretty stuck,” recalls Hutton. “It enabled an entirely new product to be developed and brought to manufacture very cost-effectively. In particular, it allowed me, Ken Symonds and the factory making the injection mould tools to communicate easily and cheaply.”

The final product weighs 2.5 kg, compared to an original weight of 4.5 kg, and it is much easier to use. The key feature of the Flexipump is that it doesn’t require replacement parts that have to be bought in a shop. Instead, when the piston cup seals wear out, farmers can make their own in the same way that they would repair a bicycle pump. The Flexipump can also be maintained without the need for tools, since all the parts can be disassembled by hand.

“The Flexipump is fixed and maintained in the same way as a bike pump, and in every village there is someone who will understand how it is made,” commented Hutton. “It can draw water from 6 m down and deliver it a further 10 m above ground, but where it really helps farmers is with transporting water over a distance. It’s possible to grow 1,000 tomato plants on a plot that is one-tenth of an acre, but it would mean carrying an enormous number of buckets or jerry cans. It could take one person five hours. However, with the Flexipump, one person could do that watering in less than one hour.”

Hutton continues to work with established distributors and non-governmental organisations (NGOs), primarily in Southern and East Africa, with a view to making the Flexipump available to small scale farmers at an affordable price, or on credit that is paid back at the end of the season.

“My dream is to give farmers the opportunity to change their lives; to exchange five hours of moving buckets for one hour of pumping,” confides Hutton. “I particularly wanted to use the private enterprise model to enable them to help themselves. With better irrigation they can achieve higher crop yields, and with more income they can spend money on items such as education. This empowers the next generation.”