Slim and Strong: Epson's Six-Axis Robots

Fast, high-precision (low vibration) and durable, Epson's six-axis robots are widely used in a variety of manufacturing industries including electronic components, automobiles and foodstuffs. At the end of 2012, Epson bolstered its lineup with its new slim and light C4 series. Containing a host of original robot technologies honed by Epson over the years, the C4 series is one of Epson's lineup of factory automation products. Despite its slim and lightweight body (C4:27 kg, C4L:29 kg), the C4 series can transport loads up to 4 kg - and being a robot it can work 24 hours a day. You can understand how powerful this is when you realize that this is the equivalent of a 70 kg person permanently carrying a 10 kg load.

The C4 series has been employed in the next-generation print head line that was announced by Epson in June 2013 (, and is contributing to the high productivity and quality of the fully automated production processes on that line.

An Epson six-axis robot used in the next-generation print head production line at Tohoku Epson Corp.

What is a six-axis robot?

Six-axis robots have six joints that can be controlled precisely to allow complex movements. They are used in factories to transport, assemble and package products.

The C4 series is comprised of the C4 and C4L, which are used for different applications. With its 600-mm arm, the C4 is used for high-speed assembly and transportation of electrical and electronic components. The C4L, with its long 900-mm arm, is ideal for work over a wider area, for example transporting parts to and from processing equipment and also small molding equipment.

The C4L (left) and the C4

Benefits of slim and lightweight design

A strong, dedicated stand is necessary to install a robot on a production line. This can be expensive. However, the slimmer and lighter the robot the smaller the stand, leading to greater space efficiency and cost savings.

Operating robots at high speed and making them carry heavier work causes vibrations that can affect robot precision and durability. One way to solve this issue is to make the robot bigger and heavier. Epson, however, believes that slim, lightweight robots provide various benefits to customers, and was from the start determined to offer these characteristics in the C4 series.

One of the reasons that Epson managed to create robots offering high speed, high precision and durability - while also reducing vibration - was its proprietary quartz crystal sensors. As the world's only robot manufacturer to also manufacture quartz devices, Epson was able to install in its C4 series original QMEMS sensors combining quartz and MEMS manufacturing techniques. These sensors allow the robots to reduce vibrations to a third of the level of models in the C3 series.

Weighing only 27 kg, the C4 series increases the payload of its C3 series predecessors from 3 kg to 4 kg. In addition, it achieves a cycle time* - an indicator of work speed - of 0.37 seconds, which is among the fastest in its class for robots with a similar arm length. When repeatedly performing the same task, the C4 series is capable of achieving accuracy levels to within 0.02 mm.

*The time taken to transport a 1 kg load 300 mm horizontally and 25 mm vertically, and back again.

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To complement its lineup, Epson also offers optional camera and software for its robots. Epson's Vision Guide is an image processing system that quickly and accurately recognizes the shape and direction of work being processed on a production line. The Vision Guide dispenses of the need for the dedicated equipment and pallet that used to be essential for determining the position of the work. This greatly reduces the time required to retool the production line to handle a new type of work, and enables greater flexibility in lines handling a number of different items. Using a color camera allows the kind of image processing pictured below.

Because it offers an original image processing system to go with its robots, Epson is able to offer comprehensive proposals and support for including robots and cameras on production lines. By offering an all-round lineup and service that contributes to the automation of production lines, the company's aim is to contribute significantly to its customers' productivity and product quality.

For more details about Epson's industrial robots, click on the link below.