Orbital machining benefits composites manufacturers

Orbital machining benefits composites manufacturers
Orbital machining benefits composites manufacturers

Sandvik Coromant has been working for a number of years with Novator, a Swedish company that specialises in machines for holemaking in advanced and complex materials such as composites and composite/metallic stacks.

Due to the scale of the holemaking operation in aircraft manufacturing and its impact on productivity and costs,
The result is a total solution based on an innovative holemaking process known as orbital machining. In the aerospace sector, CFRP-titanium and CFRP-aluminium stack drilling is a challenge where orbital machining has proven to both improve productivity and decrease manufacturing cost. So how does it work? As opposed to conventional drilling, orbital machining is actually a milling operation that involves revolving the cutter in an eccentric motion around the hole centre while it rotates simultaneously around its own axis and is fed through the workpiece. Not only does orbital machining produce the hole in a single step, but the process is extremely versatile. Just by adjusting the offset, a cutting tool of a specific diameter can be used to produce holes of several different diameters, which means cutting tool inventory can be reduced substantially. Sure enough, a CNC machining centre can perform a similar motion, circular interpolation, but such machines are much larger and hence slower and less versatile. Also, in orbital machining the thrust force is very low – a factor that results in higher hole quality. This in turn helps promote dry machining or minimum quantity lubrication (MQL), which is recommended for composite components made from CFRP-Ti stacks. Reduced lead-times and costs The cost of tools in orbital machining is reduced since both the life of each cutter is longer and the need for different types of cutters is diminished. The shorter tool life found in conventional drilling system is caused by exposure of the tool centre to excessive heat. In contrast, during orbital machining the cutting edges of the tool have only partial and intermittent contact with the surface. In combination with air cooling, this avoids overheating and prolongs tool life. Another major advantage is that a single cutter can be used for operations that include producing various hole sizes, adaptive stack drilling, complex shaped hole generation, cutting returns, countersinking and reaming. The upshot is that production lead-times are often reduced drastically. Furthermore, the advantage of not having to use coolant in the drilling process not only makes coolant cleaning and handling obsolete, it also makes it possible to drill in clean environments. In addition, dry chips are sold for a much higher price than wet sludge. Increased quality The lower thrust force in orbital machining eliminates delamination when drilling in composites, and eliminates burrs when drilling in metals. The process not only results in unparalleled surface finish, it also reduces chip-induced damage in the material. This is because the tools deployed have a smaller diameter than the hole and produce smaller chips that are removed using an airflow system. Other advantages of this innovative process include the elimination of any potential for metallurgical change, as well as the possibility of higher degrees of automation and a generally improved and cleaner working environment. The latter is important as manufacturers are increasingly recognising the need for environmentally sound production processes. The tooling Sandvik Coromant offers tooling products that are developed specifically for orbital machining applications and co-ordinated to suit Novator machines. Each customised solution, available in carbide or PCD design, is purpose-designed for the application and can be used in CFRP, CFRP-Ti and CFRP-Al. Typical cutting data for composite stacks (depending on material composition) is 18-60m/min cutting speed with feed rates of 0.08-0.13mm/rev. Tool diameters are typically 50-85% of the required hole diameters. Novator/Sandvik Coromant projects in orbital machining have already been implemented at almost all of the major aerospace OEMs. Airbus was the first large-scale adopter and, today, orbital machining is an established holemaking method in the aerospace industry. Boeing use portable machines from Novator for the orbital machining of holes to join two of the most critical parts in its 787 Dreamliner – the central wing-box and body. No other airplane parts take as much load. Of course, delivering a ‘total' solution is important and Sandvik Coromant as a cutting tool solution provider is a major part of the orbital machining offer. “The collaboration with Sandvik Coromant is really important for us. It's a well-recognised company that always delivers high quality, which is the foundation of everything we do,” says Hans-Petter Andersson, CEO at Novator. www.sandvik.coromant.com

Related Articles

Good vibrations!

Providing custom-designed cutting tool solutions for composite components, Walter AG explains how vibration drilling can help guarantee high quality for stack machining.
7 years ago Features

It’s a material whirl!

Bindatex – Europe's only independent specialist in the precision cutting of advanced materials – is working with BAE Systems to create an agile UK supply chain. Aerospace Manufacturing reports.
8 years ago Features

Six of the best

Mike Richardson meets Velocity Composites' director Gerry Johnson and managing director, Darren Ingram to hear how the company's total kit provision of engineered kits for the aerospace industry is knocking material waste for six!
8 years ago Features
Most recent Articles

Carter enjoys success at HAI HELI-EXPO event

Acknowledged as the World’s largest vertical aviation conference and trade show, HAI HELI-EXPO 2024 provided precision bearing specialists Carter Manufacturing a perfect opportunity to exhibit its extensive range of aerospace bearing installation, removal and testing tools, along with PMA bearing options.
2 days ago News

Login / Sign up