Fasteners Enable Creation of Robotic Salad Bar

Fusion automated salad bar — Photo courtesy Accu

With Fusion, an empty bowl enters the system at one end, and a completed salad—made to order according to each customer’s exact specifications—exits at the opposite end.

Times are tough for restaurants these days. In the U.K. alone, 748 hospitality venues shuttered in the final quarter of 2024. That’s an average of eight closures per day.

The core of the crisis is labor. Hospitality is the lowest paid sector in the U.K. It’s also one of the most burned out, with 76 percent of managers reporting symptoms of burnout driven by long hours, stress and chronic understaffing.

Since 2019, the number of EU workers in the U.K. hospitality sector has dropped by approximately 121,000, representing a 41 percent decline from before the pandemic. The total number of international workers leaving the sector, including those from outside the EU, is around 197,000. This has contributed to a major labor shortage, with hospitality experiencing the highest job vacancy rate of any U.K. industry at 7.9 percent.

To help improve the lot of workers, the U.K. government raised the country’s national living wage to 12.21 pounds per hour in 2025. The raise will cost employers an additional 1,400 pounds per worker. That was great news for workers, but for restaurants operating on margins of 3 to 5 percent, the wage increase only added to their bottom-line woes.

Standard shoulder bolts are key part of the Fusion machine. While many designs could have required custom-machined shafts, the ready availability of precision shoulder bolts allowed Kaikaku to swap parts quickly during development. Photo courtesy Accu

Initially, Kaikaku used brass threaded inserts to fasten certain plastic components. However, these proved difficult to install and lacked torsional strength. By switching to captive DIN square nuts, Kaikaku achieved greater reliability, simpler servicing and faster assembly. Photo courtesy Accu

London automation start-up Kaikaku set out to solve the problem. Founded in 2023 by recent college grads Josef Chen, Piers Millar and Ivan Tregear, Kaikaku was launched to address the biggest pinch points in quick-service dining: queues, inconsistency and labor shortages. If certain aspects of food preparation could be automated, their thinking went, restaurants could save labor, reduce waste and increase quality.

For Chen, the company’s CEO, launching the company was personal. His parents—immigrants from China—ran a Chinese restaurant in Austria, and as a child he spent many hours in the kitchen doing chores.

The company’s first product is Fusion, an automated salad bar that combines 3D-printed components, modular hardware and flexible software. An empty bowl enters the system at one end, and a completed salad—made to order according to each customer’s exact specifications—exits at the opposite end. The system can produce 360 servings per hour, allowing staff to focus on hospitality and quality.

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To test its concepts, the company built its own London restaurant, called Common Room. Behind a one-way mirror, the company’s engineers watch, document and adjust their designs in real time. Nothing is left to theory. Since the system was first deployed in the restaurant, it has gone through multiple iterations.

3D-printed component for automated salad bar

Kaikaku’s first product is Fusion, an automated salad bar that combines 3D-printed components, modular hardware and flexible software. Photo courtesy Accu

Accu supplied a variety of parts for Kaikaku’s automated salad bar. Photo courtesy Accu

Nuts and Bolts

Accu, a U.K. supplier of threaded fasteners, rivets and other assembly hardware, played a critical role in enabling Kaikaku to prototype, refine and launch Fusion in record time. By supplying precision fasteners ranging from DIN square nuts and ISO socket cap screws to specialist shoulder bolts and Nord-Lock washers, Accu has enabled the Kaikaku team to build machines that are both service-ready and easy to maintain.

“We aim to apply the speed of software deployment to hardware,” says Tregear, CTO of Kaikaku and the U.K.’s youngest chartered engineer. “That means testing, fixing and iterating in a live restaurant environment, often in the space of hours rather than weeks. This wouldn’t be possible without suppliers that can move as fast as us—and Accu has been vital in making that happen.”

One of the biggest breakthroughs in the Fusion build came from rethinking fastening for 3D-printed components. Initially, the team relied on brass threaded inserts that were installed in the plastic with a heated tool. However, these proved difficult to install and lacked torsional strength. By switching to captive DIN square nuts supplied by Accu, the engineers achieved greater reliability, simpler servicing and faster assembly.

Shoulder bolts, another Accu component, have also become a mainstay. While many designs could have required custom-machined shafts, the ready availability of precision shoulder bolts allowed Kaikaku to swap parts quickly during development, saving weeks of machining time and ensuring that replacement parts could be installed in the field within hours.

engineers adjusting their designs in real time

To test its concepts, Kaikaku built its own London restaurant, called Common Room. Behind a one-way mirror, engineers watch, document and adjust their designs in real time. Photo courtesy Accu

Since Fusion was first deployed, it has gone through multiple iterations. Photo courtesy Accu

A decisive moment came just three weeks before launch of the fourth iteration of Fusion. A bottleneck in the lift mechanism threatened to derail the project. In less than 48 hours, the Kaikaku team redesigned the entire assembly, placed a full order with Accu on Friday evening, and had the parts in hand the following day. The new mechanism was installed, tested and operational in time for the restaurant’s debut service.

“We couldn’t have moved that quickly without suppliers like Accu,” adds Tregear. “Their speed and precision let us overcome design challenges and stay on track for launch.”

Accu’s extensive CAD library also played an important role, allowing Kaikaku’s engineers to integrate fasteners directly into their designs before placing an order, saving time, reducing errors and ensuring a seamless fit between digital models and real-world assemblies.

“Our mission is to support innovators like Kaikaku by delivering precision components, on demand, at the pace modern engineering requires,” says Patrick Faulkner, lead engineer at Accu. “Seeing our fasteners play a part in building the world’s first robotic salad bar is a fantastic example of how speed, accuracy and reliability can come together to change industries.”

Beyond speed and performance, Kaikaku and Accu share a focus on sustainability. By sourcing components from a single U.K. supplier, Kaikaku reduces freight miles, packaging waste and supply chain emissions, helping Fusion achieve its “made in Britain” certification. Standardized hardware also extends the service life of the machines, enabling easy repair, reuse and recycling.

With the success of Fusion, Kaikaku plans to roll out its automated salad assembly line to more sites. For diners, the experience is fast, reliable and consistently fresh. For staff, it’s about freeing up time for what matters most: service.

For more information on fasteners and assembly hardware, visit: www.accu.co.uk.