Want to save costs and be more sustainable? Stop the chatter.05 October 2023
An AMRC spin out story: Dr Erdem Ozturk, founder of Productive Machines, writes about the company’s journey from AMRC origins to successful startup.
Article featured in the latest issue of the AMRC Journal.
Productive Machines is on a mission to maximise productivity of machine tools. We use our unique digital twin to simulate millions of combinations of machine settings to arrive at the optimum feed rate and spindle speed setting for a given process prior to manufacturing. This eliminates chatter vibrations and provides machining optimisation, preventative maintenance and part quality that may not be achieved by a human operator even with years of continuous improvement.
We formed in 2021 as a spin-out from the University of Sheffield Advanced Manufacturing Research Centre (AMRC) - but the journey of Productive Machines began long before that.
During my undergraduate studies and master’s degree, I found a key problem blocking the path to truly efficient Computer Numerical Control (CNC) machining: chatter vibrations. The issue of chatter has been a serious frustration in machining for many decades, but until now the only solution has been trial-and-error iteration for most manufacturers; experiments to reach a set of machine settings that minimise these vibrations.
As Frederick Winslow Taylor, an American author widely known for his methods to improve industrial efficiency, wrote in 1907: “Chatter is the most obscure and delicate of all problems facing the machinist.”
In the realm of CNC machining, the issue of chatter poses significant challenges. Like an unruly guest at a finely orchestrated event, chatter disrupts the smooth flow of operations, demanding attention. It leads to slower cycle times and to increased waste.
Chatter - the vibrations arising from unstable interactions between the cutting tool and workpiece - leads to surface irregularities and dimensional inaccuracies. These jeopardise the quality of machined components, leading to increased rework, inefficiency, scrap, and compromised customer satisfaction.
Why does this matter? It matters because the environmental costs of chatter are significant. Left unfettered it can lead to:
- Waste materials and parts. Workpieces with chatter damage are unusable, significantly increasing waste. This scrapped metal was hugely energy intensive to get to a usable state; now it is useless, thanks to chatter.
Chatter also wears down tools faster, leading to increased costs and unnecessary waste. Frequent tool changes not only add to expenses but also consume valuable time that could be dedicated to productive machining.
- Hugely increased energy usage. Machinists lose much time as they experiment to get to a spindle speed that eliminates chatter. This experimentation time is hugely costly in the wasted energy that is drawn down.
Chatter means excess energy consumption, resulting in higher operating costs and increased carbon emissions.
So, as the global focus on environmental responsibility grows, manufacturers must take measures to minimise waste and energy usage associated with chatter. That means prioritising the optimisation of machining parameters, tool selection, and machine rigidity. Changing parameters is easy to implement as it doesn't involve buying extra tools or buying a new machine tool. Chatter is a crucial problem that successful, sustainable manufacturers should be tackling head-on.
Optimisation of milling processes figured heavily in my research and by 2005, I had started my PhD on the stability of five-axis,ball-end milling processes culminating on a published predictive model  against chatter vibrations in the Journal of Manufacturing Science and Engineering. Using this model, a process planner was able to predict the optimum cutting depth and spindle speed combinations that would avoid chatter vibrations.
The University of Sheffield AMRC: a nurturing environment
In 2010, I had the opportunity to work for the University of Sheffield Advanced Manufacturing Centre (AMRC) and put my theory into large companies in the aerospace industry. The AMRC’s world-class manufacturing facilities and steady flow of machining challenges introduced by its partners and clients, created the perfect stage.
The AMRC is a beacon of innovation in the manufacturing industry, connecting leading manufacturers with research, consistently driving advancements and fostering promising startups.
I formed a research team and together we worked to push the boundaries of the machining dynamics field using specially developed digital twins and simulations to improve productivity, extend tool life and eliminate chatter.
During my time at the AMRC, the team continued to grow and I had the privilege of working with lots of amazing individuals who supported the machining dynamics team, from staff members and PhD students, to MSc students and visiting researchers.
A lot of the simulation techniques we were using to overcome our partners and clients' machining challenges simply weren’t available to most manufacturers who still broadly used trial-and-error to achieve desired levels of productivity and quality.
The research team developed digital twins for the machining processes that had unique selling points compared with commercially available products and I was able to go beyond reports and publications to form a successful startup with industrial impact.
With access to cutting-edge research, state-of-the-art facilities, a pool of internationally significant expertise in machining at the AMRC, and the network of companies looking at the AMRC for innovative solutions, a research project rapidly formed into a highly promising startup - Productive Machines.
Thanks to the support of the University of Sheffield, the AMRC, and the ATI Boeing accelerator program, Productive Machines was formed to bring the results of this groundbreaking innovation to every machining workshop and to make the technology and techniques we had developed through the AMRC’s machining dynamics team available commercially.
Today, the company has already impacted leading manufacturers from a variety of sectors from medical to construction. Productive Machines has raised a cumulative £3m investment and grown an amazing team of 19 exceptional staff. We continue to work closely with and enjoy the support of the AMRC and have exciting growth plans for 2023 and beyond.
Why was Productive Machines formed?
There was an opportunity to bring cutting edge technology and offer it as a straightforward Software as a Service (SaaS) product; to create a future where every manufacturer and machine operator can elevate quality, productivity and sustainability. We wanted to make cutting optimisation technology accessible to all, regardless of the scale of operation or expertise.
Productive Machines' vision extends beyond mere technological advancement; it's about empowering manufacturers and machine operators to excel, to save costs - and to help save our planet.
Our technology plays a crucial role in boosting sustainability and productivity in manufacturing. By finally solving the old and frustrating problem of machine tool chatter, this technology could save a staggering 2.5 gigatonnes of carbon dioxide emissions by 2050. To put this into perspective, 2.5 gigatonnes is equivalent to the UK’s total CO2 emissions - every factory, fire, car, flight and light - for six years.
How can this be achieved? In short, by making big changes to two sides of the sustainable manufacturing triangle: optimising machine settings to cut waste and reduce energy used.
Why does CNC matter for sustainability?
In modern manufacturing, one technology stands as a cornerstone: CNC machining. It produces everything from aerospace parts to the casings of Apple Mac computers to jewellery. And even where it does not directly produce the finished product, as in, say, the food industry, it is CNC machining that makes the machines that produce almost everything else.
CNC manufacturing has driven the advanced manufacturing processes that have redefined efficiency, accuracy, and cost-effectiveness. Its level of precision has revolutionised industries ranging from aerospace to healthcare, enabling the creation of cutting-edge products that were once only imaginable.
Its versatility empowers designers and engineers to explore new frontiers, unleashing unprecedented creativity in fields as diverse as custom prosthetic limbs to engine parts and chassis components. It is the tool that is building the 21st Century world.
CNC machining is a huge industry (estimated at $96 billion in 2022 according to a recent research study by Contrive Datum Insights) and it is growing fast. Five-axis machine tools have brought radical improvements in capability and cycle times, and alternatives such as additive manufacturing are not always the best commercial or technical option.
So optimising machining for efficiency and sustainability matters.
CNC machining and sustainability
CNC machining has a crucial role to play in environmental sustainability. Every day across the globe, CNC machine tools turn energy and raw materials into the components of vehicles, computers and just about everything else we use every day.
There are around four million CNC milling machines globally, drawing down huge flows of energy. At that scale, improvements in efficiency can have a huge net effect. This is the promise offered by technology like that of Productive Machines.
Because of the huge scale of CNC machining, we can have a big effect fast. Groundbreaking innovation like that from Productive Machines can therefore pave the way to a greener and much more sustainable manufacturing future.
How does our technology work?
With our unique technology, customers get to the best part, faster, the first time.
Using artificial intelligence (AI)and digital twins of the milling process, we identify parameters that will be vibration-free, automatically personalising the process to eliminate chatter. This dramatically cuts cycle times, which in turns dramatically cuts energy consumption and CO2 emissions.
It’s a little like producing noise-cancelling headphones for milling machines. As with advanced headphones, we model the situation electronically and put in place a solution that cuts out the noise or chatter we don’t want.
This enables us to bypass the iterative process of getting to chatter-free settings that holds up, and adds cost to, manufacturing. By eliminating chatter vibrations, machining companies get to the best part, faster, first time with reduced cost, energy usage and waste.
We do this by simulating millions of combinations of machine settings to find the optimum - an optimum that humans would never reach, even with five years’ continuous improvement.
Using these mathematical models and simulations we see remarkable results. For example steel firm Ficep UK saw the productivity of their process increase by 110 per cent, with cycle time cut by 53 per cent while reducing the magnitude of vibrations five times.
Unlocking potential: the workshop results of anti-chatter technology
In our work with global manufacturers including Ficep, Renault and MASA Aerospace, this technology has shown it can:
- Cut the machining design and set-up time by 20 per cent
- Cut cycle times by ten to -53 per cent
- Cut operational and maintenance costs by 25 per cent
- Reduce cutting tools costs by 11 per cent
- Reduce cutting noise by five times
So, the technology offers a huge increase in productivity, massive reductions in cost and a very significant sustainability impact.
Key benefits for manufacturers
- Accelerated time-to-first-part: achieve faster production cycles, reducing lead times to deliver the first part swiftly.
- Lower production costs for the first part - attain the bulk quantity price faster.
- Cut energy costs by up to 25 per cent.
- A stand alone solution. Rely on our technology to analyse for optimal results without the need for PhD-level experts of your own.
- We can optimise milling machining processes in minutes instead of weeks, at a fifth of the cost and without expert engineers.
- Proven technology: it is already deployed at ten major manufacturers, including Renault and MASA Aerospace.
Six reasons to eliminate chatter in CNC machining for sustainability
- Waste reduction: Chatter elimination optimises cutting, reducing material waste and supporting sustainable manufacturing practices.
- Resource efficiency: The longer cutting-tool life achieved through chatter reduction means less need for frequent replacements.
- Energy conservation: Reduced vibrations lead to lower electricity consumption during machining.
- Enhanced product quality: Chatter elimination results in improved product precision, reducing defective parts.
- Extended equipment lifespan: Smoother machining operations reduce machine wear, prolonging the life of CNC equipment.
- Safer work environment: Reduced cutting noise improves workplace safety and contributes to a healthier workplace.
 Ozturk, E., Budak, E., (2010), Dynamics and Stability of Five-axis Ball-end Milling, Journal of Manufacturing Science and Engineering, 132, 021003-1-13, doi:10.1115/1.4001038