Servo tube linear motors tick all the right boxes for Graze

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If you are into healthy and nutritious snacks, have bought anything from Amazon recently, or are a follower of the Sunday Times “Fast Track Top 100 companies”, then you will have heard of Graze. The west London-based business, started by seven friends, delivers boxes of four perfectly sized nutritious snacks across the UK by post. However, what’s unusual about Graze is that it customises each customer’s boxes based on their ratings and preferences and optimises the freshness of each ingredient used. Graze is much more about than just food though; it’s also about how they have applied cutting-edge technology to meet the significant challenges of their complex production methods.

Graze’s needs were challenging. Right from the outset they were told that it wasn’t possible by industry experts; the production line specifications were going to be difficult to achieve, standard machines would struggle to offer the performance criteria for throughput, waste and maintenance. The production line was required to process weighed portions of the various snack products and dispense them into different format punnets. These would all fit inside the standard Graze box, designed of course to fit through a standard letter box. Due to the millions of combinations of ingredients it would require multiple positions to suit the box configurations and these would need to be high speed to cope with projected throughputs. The potential for contamination meant wash-down capability was a must, and all parts had to be of a smooth, hygienic, design that was free from potential dirt traps.

For Graze, a company that was by now used to people saying “it’s never been done before” and “it can’t be done”, the movement and positioning of their weighing system was yet another area where they had to challenge the industry norms and take on the seemingly impossible.

Ben Jones, co-founder of Graze, says: “Everyone said it was impossible, yet we built a successful company that sent fresh fruit through the post.” Using an algorithm, called ‘Darwin’ (Decision Algorithm Rating What Ingredient’s Next), the system determines how snack portions are sorted into punnets, and it is possible to get millions of different combinations of snacks placed into customised Graze boxes, labelled and sent by post. The ‘what’ was therefore sorted, but overcoming the challenge of how to solve the problem still remained.

After seeing the ServoTube range displayed on the Dunkermotoren Linear Motors stand during a visit to the PPMA exhibition, another co-founder of Graze Neil Thompson, knew he’d found the solution. It was the Hygienic XHA motor, running under water in a fish tank on Dukermotoren’s stand really caught his eye and, realising the potential of the Servo Tube Range and how it could be applied to their complex challenge, Neil arranged for his engineers to visit Dunkermotoren’s stand to discuss how they could be utilised.

Infinite series of positions

During the following months Dunkermotoren’s engineers worked closely with Graze’s machine designers to produce an XXY gantry formation using three XHA38 series tubular linear motors. By mounting the linear motors as actuators to utilise the integrated field-replaceable polymer lubrication-free slide bearings, it was possible to push the dosing head through an infinite series of positions. The ServoTubes IP69K ingress protection rating, thanks to its non-corrosive all stainless construction, met the requirement for food-safe and no dirt-traps, while the high force output from the motors enabled Graze to meet the speed and acceleration specification with ease.

Finally Graze had a system that would meet their throughput needs. The millions of combinations of ingredients results in huge numbers of individual portions, or ‘picks’ as Neil Thompson of Graze describes them. Neil comments: “Believe it or not, we can now make more individual picks than the other established, big name online grocery delivery companies”.

Graze, with its Darwin system, custom-built machines and the desire to be sustainable and innovative, incorporated Dunkermotoren’s ServoTube linear motors into their lines. This helped them achieve their production performance requirements of high line speed and increased productivity with the key benefits of fast and precise positioning. The result is less waste, reduced maintenance and lower costs, simplified set-up, lower noise levels and ultimately, increased profitability.

As a result of the increased throughput and flexibility offered by Dunkermotoren’s ServoTube linear motors, Graze’s Darwin theory is more revolutionary than evolutionary. After launching the product in America the company smashed its first quarter targets and are currently going through a very exciting period of expansion. They have also expanded their UK product offering to include breakfast and kids boxes.

Dunkermotoren’s high-speed speed linear actuators offer no-compromise linear motion for the most demanding hygienic and industrial processing environments and other contamination-sensitive applications. The internal position sensor is always accurate, and is protected from debris or damage because it is built into the direct drive linear motor’s body. Whereas alternative belt drive and ballscrew drive linear systems comprise of several component parts, frequently with lower IP ratings and food-traps, the ServoTube range of direct drive linear motors are both mechanically and electrically simple, requiring only a standard servo drive. This reduces system complexity, maintenance and saves space, because no servomotor or gearhead is required.

For more details on Dunkermotoren’s Servo Tube range of linear motors please visit the website at

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