Casting & Molding | Machining | Finishing & Painting

Scotts, a trusted name in the gardening tool market, saw an opportunity to use existing behavior to develop a product that enables gardeners to feed as easily as they can water. The project had several goals: the device needed to adapt to any watering device, adjust to any water pressure, fit in a small, compact size and accurately dose the Liquafeed fertilizer solution.


Industrial fertilizer pumps surfaced as an example of the desired product functionality, but their large size and expensive parts became a challenge. Our internal engineering team transformed this industrial technology into an affordable and effcient consumer product with an astounding $20 price point. The operation is simple: either rotate the lever to “Water” to bypass the feeding, or to “Feed,” to dose the solution into the water stream. With that simple adjustment, gardeners can feed and water at the same time without switching their sprayer. The Miracle-Gro Liquafeed Universal adapts to any watering device and varying pressure, while using Scotts’ existing product offerings to create a powerful tool for the garden. 


The mechanism uses water pressure to power and adjust the internal mixing engine, delivering the correct ratio of liquid plant food to water. Early in the process, modifications were made to existing pumps to understand the mix that was needed. The whole product needed to be highly adaptable, not just the mechanism. Internal engineers and designers worked with our prototype team to machine the housing design. This housing along with a series of o the shelf parts created the first concept.


Using what was learned with the first concept, we created data to print 3D parts on our Eden 5500. This led to a series of proof-of-concept prototypes that were created using a mix of these 3D printed parts and machined parts. The early 3D printed parts were made from clear resin in order to see the action and ow of the water. The water flowed, just not always as expected. Our team of prototype specialists and engineers fought leaks and solved problems. We had to get the correct mix ratio to keep the mechanism from leaking. In order to do so, we tested different “o” rings and seals, adjusted valve designs, and through the all the prototype iterations, we developed a mechanism that could deliver the correct mix without leaking. The main goal of these proof-of-concept prototypes was to confirm the function and durability of the design.

The next step was to CNC machine a working prototype of the internal pump. The main pump body was the key feature of the design. It housed all the parts that made this design work the way that was intended. The complex design of the pump body was machined from a solid block of Delrin. We chose Derlin to get as close to final production material as possible. We started with a perfectly square block that was rotated after each side was machined. The final part was left suspended inside the frame work of the block until the final details were completed for each side. After all the machining was complete, the finished part was cut out by hand. Other parts of the mechanism, such as the pistons and pump arm, were also machined. The pump body was inserted into a clear Objet printed housing. We left the body clear to view the action of the internal parts as they worked. We had to verify if they were mixing the water and feed correctly. After some tweaking and several pump iterations, the engineering prototype accomplished the immense goal. The resulting product was 25% of the size of industrial fertilizer pumps and only 10% of the cost.

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