Bumotec solves medical puzzle for Dawnlough Precision

The Two Bumotec 191neo machines in the new machining facility at Dawnlough

Ireland-based Dawnlough Ltd is a sub-contract manufacturing business in Galway that specialises in precision engineering, providing a variety of manufacturing solutions for customers in the medical device, aerospace, and automotive industries. The company has experienced rapid growth since it was established in 1987, with an ethos of continuous investment in high-end machine tools — which has included the recent arrival of two Bumotec 191neo turn/mill centres supplied by Starrag UK Ltd.

Since the turn of the millennium, Dawnlough has gained accreditation to ISO: 9001, ISO: 13485 and AS: 9100D, established a design department and increased its manufacturing facility to 50,000ft². Underpinning its rapid growth is the adoption of advanced production tools such as FMEA, PPAP and SPC. The world-class production facility has more than 54 CNC machine tools that provide premium manufacturing solutions. Recently acquired by the Acrotec Group, the 110-employee business is still run by long-standing managing director and previous owner Brian McKeon.

Keith Kennedy, Dawnlough aerospace production manager, said: “We manufacture high-precision components for the aerospace and robotic-assisted surgical industries as well as tooling and production aids for the medical device sector. When I started in 2006, tooling was the main business focus, but as the aerospace and medical device sectors have expanded locally, this presented many opportunities. Our aerospace work started with seating components for Rockwell Collins, which led us to move into five-axis machining. We then progressed to flight-critical components for the likes of Spirit Aero Systems and Pratt & Whitney. Similarly, we progressed from manufacturing medical tooling and instruments to producing complete assemblies.”

Discussing the expansion in the medical industry, Mr Kennedy continued: “Our core business has predominantly focused on vascular work and from this, we have expanded our offering. We now produce a variety of components for our RAS customers as well as consumable instruments.”

It is here that the search for a suitable machine led Dawnlough to purchase a Bumotec 191neo FTL-R in June 2022. Discussing the acquisition, he reflected: “We had several components we initially targeted for this type of machine. We needed a mill/turn centre with very high levels of accuracy, short cycle times and incredible efficiency because it is a very competitive market. We visited many suppliers, but it is only as you look closer and purchase one of these machines for this type of work that you really see the ‘value-add’ they bring. We were looking for repeatability, flexibility, high-spindle speeds, the ability to machine hard material and 2-3µm precision on production runs. We had very specific requirements and we were not sure if it was going to be achievable.”

“Some of our initial trial parts were 46HRc and we are using tools from 0.1-0.5mm. We needed repeatability of 2-3µm, but we needed to hold that overnight. Some of the functions of the Bumotec machine such as the software for monitoring the machine, the cutting load, the contact cutting time and the large 90-tool automatic tool changer (ATC) in the machine are incredible. It was a huge investment and an unknown risk, but the Bumotec ticked all the right boxes. We were particularly attacted by its flexibility. It is an exceptional machine with accuracy that takes our business to a different level.”

As well as machining 46HRc parts, there was also a need for specific RAS parts that were a key driver to the first Bumotec installation. Mr Kennedy added: “We were machining these parts in batches of 200-off up to six times a year and there are six different parts in the family with a projected ramp-up of 200-300% a year. So, we would not have been able to support the customer with our existing method.”

Mr Kennedy added: “We needed to put a bar diameter in the machine up to 1.5in while also running high-precision production runs of small instrumentation parts. The Bumotec also had the sub-spindle and a robotic unit which was important, as we need traceability for every part we make. We literally took demonstration parts to Bumotec in Switzerland in April 2022 and we received the machine in the June of that year.”

Huge success
Following the huge success of the Bumotec 191neo with FTL-R configuration, the Galway company then added a second Bumotec 191neo in March last year. Supplied with an FTL-PRM configuration, the second machine featuring complete automation and a 20-position pallet station for lights-out production. Mr Kennedy explained: “What they offered us with the second machine was a complete turnkey solution for our instrumentation components. We had given them a target for extreme levels of precision and production volume with the flexibility to produce families of parts.”

“We needed to machine materials from 46 to 52HRc such as 17-4 and 420 stainless steel as well as titanium. The instrument parts for use in invasive robotic surgery include tools like grippers, cutting instruments and scissors. We are producing the parts in medium to high-volume runs across two different parts in various quantities per month.”

Some of the parts had very long cycle times on the five-axis machines and this needed to be reduced to below 30min with 48HRc material. Not only was the cycle time a challenge, but Dawnlough had to attain precision levels in a production environment with the flexibility to produce upwards of 30 different components. Initially machining 20 to 50 parts a month, the schedule was set to rise rapidly to 200 parts per month before reaching production volumes – numbers not possible on a five-axis machining centre.

Mr Kennedy said: “With the second machine, we knew exactly what Bumotec could do, so we worked with the company remotely. What Bumotec offers is exceptional and way beyond anything we had anticipated. With the original Bumotec 191neo FTL-R, we had the sub-spindle, but with the next set of parts we needed the Bumotec 191neo FTL-PRM. With this machine, we had the option of the vice, a 3m bar feed and also a robot loader. We needed the robot loader for traceability. It also expanded the capacity of the machine where we could go from 50mm barfed stock to 80mm billet loading.”

“The sub-spindle option we had on the FTL-R wasn’t feasible for the parts we needed, whereas the FTL-PRM gave us two vices. Without the vices, we would have needed to undertake secondary machining, so to be able to pick up the component in the vice and conduct the second operation in a single cycle was key to finishing the parts.”

Dawnlough’s general manager Eddie McHugh added: “We were machining parts on our five-axis machining centres and we needed to increase output by 400%. We were machining around 400 parts a month on two different products with a cycle time of 45min. This was tying up two machines and one man permanently every month. On second and third shifts with fewer staff, we had concerns about machine tolerance drift, so output was reduced and it also made inspection labour intensive.”

Looking at additional savings with the arrival of the Bumotec 191neo FTL-PRM, Mr McHugh added: “There is a labour-saving aspect with one man running two machines around the clock. Additionally, with the pallet loader, the parts are loaded into the machine and back to the pallet loader in a specific order which made huge savings on inspection. We have also made considerable savings on tool costs and changeovers and this is a credit to the 40,000rev/min spindle.”

With machine tools from 10 different manufacturers, Dawnlough has one machine alongside the two Bumotec 191neo that is commonly used in the medical industry. Comparing this machine to the Bumotec, Mr Kennedy continued: “In comparison, the Bumotecs have increased capacity, larger tool libraries, higher spindle speeds, larger diameter bar capacities and other features that just offer so much more flexibility. They are not only a better and more flexible option, but are also more robust machines.”

Looking to the future, Dawnlough has plans for more Bumotec machines and continued expansion, which will certainly continue with the ambition of the Acrotec Group. “The machines are extremely flexible and this means we can just change the programmes over, the jaws and collets and it is ready to go in less than 2hr. For our high-precision mid to high volumes with a high mix of complexity – the Bumotec is the perfect machine for our business.”

Mr Kennedy added: “The Bumotec service is exceptional — there is absolutely no comparison to some of our other machine suppliers. Starrag is a brand with a limited footprint in Ireland and I believe our Bumotec was in fact its first machine installation in Ireland. Despite other brands having a larger footprint in this area, the Bumotec support is second to none.”

Mr McHugh concluded: “The service from Bumotec is probably the best we have had. If you need engineering support they are there straight away, whether it is engineering support, post-processors, technical queries or anything else.”