How to lift 5 litres of water up a height of 60cm in the most efficient manner possible? The pump had to be capable of performing this task in under 5 minutes, powered by a 24V DC motor. If possible, ignore the innuendo.

After some prototyping and testing we selected the reciprocating pump design as it was simple, effective and (we hoped!) efficient. This is it, to the right. Apologies if the gifs make you dizzy.

The most complex part of our design is providing the linear motion to power it. The pump itself is simply a tube with a valve at the base. The valve allows water to enter the tube on the down-stroke, but prevents it leaking out on the up-stroke.

Down you can see the majority of our components, as well as close-ups of our guides and sliders.

The yoke was lasercut to ensure a precise form and smooth edges, reducing friction when in motion. The guides were 3D printed for accuracy, as they are a relatively complex shape and required quite high tolerances to avoid jamming. They also have low friction when in contact with the plastic yoke. The clamps were also 3D printed to ensure a good fit with the cylindrical pipe.

After translating rotating to linear motion successfully, we continued with the rest. He couldn't decide on the valve very easily - flapper or ball, but quite some tests later, we decided on the ball.

Part of the task was to publish a post on instructables explaining how it's made, click to see in detail.