act/cut 3d helps to cut the tubular frames of motorbikes at Nakamura

Located in the center of the Japanese archipelago, the city of Hamamatsu is one of the largest industrial centers of the country and the region is considered to be the Mecca of the motorbike industry, a place unique in the world. Indeed, Honda and Yamaha have decided to locate their main production plants there and Suzuki, its headquarters and Research & Development platform for its “two-wheel” department. Many subcontractors are also established in this region, such as the sheet metal working and prototyping company Nakamura whose specialty is to design prototypes of motorbike tubular frames, this activity representing 70 % of its turnover. This small firm which employs just 10 persons including the President Yukihiro Nakamura, counts among its customers the four largest motorbike manufacturers in Japan: Honda, Yamaha, Suzuki and Kawasaki.

Prototypes that are complex but ready for series production

Despite the high pressure on prices imposed by manufacturers and the ever fiercer competition between prototype specialists, the company Nakamura, without even one representative, has a full backlog of orders and does not need to unreasonably decrease its prices to outperform its competitors. The secret of this success: its technical know-how that has systematically been upgraded since the creation of the company 25 years ago and which is highly appreciated by its customers: “As soon as I am asked to create a difficult prototype that other companies were not able to make, I immediately feel enthusiastic about it!” says President Nakamura.

Helping the customer to mass produce his part in a cheap and efficient way, using only the equipment he already owns is the principle adopted by the company Nakamura. Thus, once the prototype is created, the customer can immediately start manufacturing the part on its production line. He just has to use the machining tools and data that Nakamura chose to implement the prototype. This is why Nakamura is often consulted by some car manufacturers to prepare the production of new products.

Introducing laser cutting to increase productivity

In May 2005, Nakamura installed a 5-axis laser cutting machine in a new workshop built near its headquarters. The laser, which replaces the use and change of cutting tools, is well adapted to the machining of small batch parts and to continuous multiple machining. Laser machining will now be used instead of press cutting and other mechanical machining. Besides, the laser technology enables the users to machine with “bevels”, which results in a curved section that perfectly adapts to the part to which it should be assembled.

Nakamura has chosen a laser machine manufactured by Nippei-Toyama, one of the world leaders of machine-tools for the car industry. For its machines, Nippei-Toyama has adopted a system to move the head so that the laser beam is always oriented towards a central point of the part to be machined, which guarantees regular moves of the head, including when machining complex-shaped parts. The model chosen by Nakamura has a power of 4 kW which enables the user to machine parts of very different sizes (maximum dimensions: 3,100 x 1,900 x 800 mm). Besides the performances of the machine, Nippei-Toyama is able to follow up the relationship with its customers and to focus on their needs, which strongly contributed to Alma choosing Nakamura. Mr. Nakamura explains: “We think we can rely on Nippei-Toyama’s support when the development of new techniques will require upgraded functions of the machine or new additional peripherals”.

Software enabling the user to machine tubes in optimal conditions

To pilot the laser machine, Nakamura has adopted Alma’s act/cut 3d solution, able to import the CAD part data, to implement the machining programs but also to process the data for manufacturing fixing tools with the act/tools module, which is especially important for Nakamura. Indeed, the parts making the motorbike frames, of big size and complex shape, already curved, are not easy to fix with a mandrel and require special fixing tools, the laser head moving around the part. The software is able to calculate the optimal shape of the fixing tool, so that the presence of this tool disturbs as little as possible the implementation of the machining.

The bevel cutting, systematically used for the motorbike frames made of assembled tube parts is also a strong point of act/cut 3d. As the control of the 5 axes enables the laser head to move freely, the software is able to generate a section presenting a very complex 3D shape. This is a function that was not to be found with a traditional CAM, only able to cut tubes perpendicularly to their axis. At last, thanks to the off-line programming implemented with act/cut 3d, the cutting head that executes complicated moves, moves smoothly and precisely. A representative from Nippei-Toyama, who proposed act/cut 3d to the company Nakamura and guaranteed the performance of this software, sums up: “Different software exists on the market, but act/cut 3d, which proposes the most advanced functions for machining tubes with a laser, is obviously the best in this field.” Other advantage:act/cut 3d is perfectly compatible with ThinkDesign, a CAD developed by the company Think3 and used by Nakamura.

Reducing manufacturing times and meeting new challenges

In the sheet metal working field, many firms have already adopted the laser technology, but those which use a 5-axis machine to cut tubes are rare. Thus, the techniques required for this application are still to be developed. Mr. Nakamura wishes to optimize the capacities of the laser machine and act/cut 3d software. For example, he would like to develop universal fixing tools aimed at cutting tubes, by focusing on original ideas. Moreover, to manufacture a fixing tool, a technician currently needs a whole day. Thanks to the 5-axis laser machine and act/cut 3d software, Mr. Nakamura proposes to divide this time by ten, the cutting time by three and thus to reduce the delivery time that had already been divided by two (from one month to two weeks) in the three last years, on customers’ urgent demand.

Moreover, the company is currently studying how to introduce a robot that would operate with the 5-axis laser machine. It is also looking at implementing welding on the same machine. This project aims at executing continuous cutting and welding to improve productivity and reduce times. In the future, Mr. Nakamura would like to implement an automated line to form, fold, cut and weld, by digitising the data that will be collected. That would enable him to propose to companies which use series production the technology and expertise necessary to manufacture motorbike frames. He also contemplates doing some design work for new products in the car industry. As the act/cut 3d software has opened new possibilities, Mr. Nakamura is already imagining his next challenges: “We refuse to be prisoner of fixed ideas. We shall modify the equipment layout or the stage sequence within the processes without hesitation as soon as we find better solutions. We shall always be looking for more efficient manufacturing methods.” He is even thinking of the day when cars and motorbikes will be manufactured in a different way, “if the collision-control technique is sufficiently advanced to allow the manufacturing of cars that never collide”. Also, nothing proves that the frames made of metallic tubes will always be used, that is why, as a visionary determined to meet new challenges, Mr. Nakamura is already interested in the machining of plastic materials.

© 2005 Alma