Cutting through the wear and tear

PCD1
PCD1

Tooling specialist, M.A. Ford develops its products to meet the growing needs of the composites manufacturing sector. Mike Richardson hears why, when it comes to difficult to machine materials, it’s important to have the right tool for the right job.

With significant investment in UK manufacturing plant and staff totalled more than £2.1 million between 2013 and 2015, and a further £1m in 2017 covering two state-of-the-art tool cutter grinders and MRP systems and upgrades, you could say that M.A. Ford Europe’s path to success is almost as unstoppable and unwavering as the path its tooling products cut through composite materials!

Established in 1998 and set up in Derby to provide a European sales and customer support operation for US precision cutting tool manufacturer, M.A. Ford Inc, the employee-owned company with warehousing and manufacturing operations worldwide concluded 2017 by winning a ‘Made in the Midlands’ Award for best export sales performance, after achieving year-on-year sales growth of 20%.

I last visited the company’s custom tool and UK tool production facilities, located in Leeds back in 2016, so thought it was time to check up on its progress and start by asking M.A. Ford Europe’s managing director, David Ward precisely why specialised composite cutting tools are needed as opposed to using traditional metalcutting tools.

“Composite materials form swarf when machined, which is different from typical ferrous and non-ferrous metals that form chips,” he begins. “For composite machining, cutting tool wear is a primary problem. This can be accomplished with unique wear resistant carbide grades and specialised coatings. Often the coatings used will be CVD diamond coatings or Diamond-like coatings. In addition, polycrystalline diamond (PCD) tipped tools can be used for maximum tool life. Tool geometries typically feature high rake angles to provide high shear in the machining operation. Geometries must be optimised to provide desired finishes when drilling or routing.”

On the finishing straight

In terms of the elements of composite drilling, i.e. feed/speed, swarf removal, heat build-up, delamination, cracking, fibre breakout, what needs to be considered for a typical job and how do they differ to metallic drilling?

“Composite drilling and metallic drilling are totally different applications. Metallic drilling can withstand higher heat from the drilling operation without damaging the work material. With composite drilling, heat generated during the drilling operation can result in damage of the composite material, such as melting or delamination of the work material.

“In many composite drilling operations, hole finish on the entrance and exit are critical. In almost all composite drilling operations, the exit hole is especially challenging to produce an adequate finish to meet customer requirements.

“This is accomplished through the use of high rake angles to create the necessary shear to produce acceptable finishes. We utilise complex drill point geometries to produce minimal delamination, fraying, and chip-out of the composite material. To meet the combination of hole finishes required and drill life, most composite drilling is accomplished through speeds higher than those used in metalcutting, with feedrates typically lower than the feedrates used in drilling of many metallic materials.”

Ward believe that for any machining operation in composite materials, there are two end results the customer is interested in: acceptable tool life, and acceptable part finishes.

“For milling or routing of composites, geometries required to produce an acceptable finish in composites are unique compared to geometries used in metalcutting. For composite milling, the integrity of the cutting edge is critical in order to produce the finishes required throughout the life of the tool. Finishes on the cutting tool must be of high quality. Carbide grades and tool coatings must be optimised to protect and preserve the cutting edge.

“To produce an acceptable finish in the composite milling operation, M.A. Ford utilises special cutting geometries, such as compression and fine-nicked routers which utilise both a right-hand and a left-hand cutting section of the tool. Typically, compression routers are used in heavier milling cuts with fine-nicked routers used in lighter trimming operations.”

I’m interested to know about the technical challenges posed by different kinds of composite materials and how M.A. Ford improves efficiency, reduces cost and maintains quality production of holes and surfaces?

“The main factor in helping improve efficiency and reducing costs in machining of composites is working closely with the end user. Composite materials can vary, and tool designs must often be optimised, depending on the specific composite material. Consistency of the cutting tool is critical. Carbide grades and coatings must be optimised and consistent from tool to tool to prevent variations in tool life.

“One factor we’ve seen from our end users is the need for reduced lead-time in the production of the cutting tools. Many customers often see 18-week or more lead-times for special composite tools. By cutting the lead-time and consistently meeting it, the end user can greatly reduce their inventory of these high performance, high cost tools. In most cases, new tool designs must be tested by the end users in extensive life and part finish tests. Many composite parts are used in critical industries that require extensive testing in order to implement new design ideas.”

Regarding the main focus areas of M.A. Ford’s R&D activities, Ward says the company works with major composite manufacturers to improve tool life, tool consistency and part finishes. These tests almost always have to occur at the end user due to their customers safety and design requirements.

“This means that test tools must be produced quickly in order to allow the customer to perform tests when their workload allows. We work with end users on the design of the tooling prior to the test, and depending on these results, the modifications to designs for additional improvements. Once tooling is approved, then consistency of the product is critical, meaning that carbide grades, coating, tool geometries and grinding processes must be consistent at the tool manufacturer.”

Innovation meets automation

And while much is being discussed about improving the automation of the drilling process with the twin goals of higher volume and lower cost production, what is Ward’s view? Does the process still require a lot of hands-on manual intervention?

“As a tool manufacturer, it’s always ideal to see tools used in automated processes since they can be more consistent and allow for more consistent tool life. However, especially in the aerospace industry, tools can often be used in handheld equipment. Here, tool design should be optimised to enable human intervention in the process. This sometimes requires tougher cutting edges and more robust tool design.”

‘Crystal ball’ question: what kinds of technology developments does M.A. Ford foresee in the composites tooling arena going forward? Ward reckons most of the technology developments are at the micro level of the tool design such as carbide grade development, coating enhancements, and cutting tool edge integrity.

“These features work together to improve consistency and lower machining costs for our customers,” he concludes. “In addition, we anticipate, polycrystalline diamond (PCD) tipped tooling to continue growing in popularity. Also, PCD tipped technology is being enhanced to allow for smaller diameter tools to use PCD.

“The size of M.A. Ford as a company allows us to be responsive to our customers’ needs. Our Custom Tool Divisions allow for us to focus on specialised cutting tool designs and our expertise with our technical sales support allows for us to assist customers in optimising their tool life and lower their machining costs. M.A. Ford has been producing cutting tools for nearly 100 years. Our experience can help customers, and they can rest assured they we’re there to assist them long-term.”

www.maford.com

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MA Ford Europe

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