What does SCARA stand for?
It stands for Selective Compliance Assembly Robot Arm as it has freedom of movement on some axis but not all. They have full range of motion in the X and Y axis but they cannot move in the Z axis.
When was the SCARA robot invented?
The SCARA robot design and prototype was invented in 1978 at a SCARA study group by Professor Hiroshi Makino who was part of Yamanashi University. The company Fujitsu also participated in this study group and developed the world’s first SCARA based on the concept from 1978.
Where was it first used?
After the second successful prototype was produced, Fujitsu and Toshiba started to manufacture SCARAs in 1981 for their factories and for other manufacturers.
Sankyo Seiki, a Japanese based music box manufacturer, was one of the first to use SCARAs on their production line. The company used them to assemble PBCs for audio amplifiers. Other companies like Hirata and NEC were also among the first to own a SCARA.
Who was the first company to sell them?
Fujitsu commercialised the robot first and it was used for mounting parts on PCBs, carrying out tests on mobile phones, conveying masks in clean rooms and carrying out tests on hard disks. They first introduced them to commercial assembly lines in 1981 which enabled Japan to cause an electronics boom worldwide.
How do SCARA robots work?
SCARA robots consist of two parallel joints which enable it to move in the x and y axes. This two-link structure also enables it to extend and fold into and out of confined areas. It is also able to rotate its gripper around the vertical axis and move the gripper in the z axis giving the SCARA robot 4 degrees of freedom.
They also have one base motor which then had to carry all other installed motors on the body. Their workspace is cylindrical but the robots back area may not be usable if there are cables there.
What are the advantages of SCARA robots?
They are high speed and compact robots that are also durable. They have incredibly high precision due to their mechanical rigidity in the z-axis, the axis in which the arm does not move. Their repeatability is also much better than the normal 6-axis robot at 10 microns compared to a 6-axis’ 20 microns. Their bases allow for easy and unobstructed mounting and their bodies allow for the option of cleanroom specifications. Also, due to their two-link arm they are suitable for applications which require it to reach into an enclosure.
What are the disadvantages of SCARA robots?
They have a small range of motion due to their small size and have limited flexibility as they only have four degrees of freedom. They also have small payload capabilities of around 2kg which limits their applications. Their cylindrical work envelope doesn’t suit all possible applications and it is a small envelope when compared to 6-axis and delta robots. They also have limited dexterity due to their limited degrees of freedom and are expensive when compared with cartesian robots.
What applications can SCARA robots be used for?
SCARA robots can be used for a range of small workpiece applications. Pick and place is one of their most popular applications as they are highly accurate, the quickest, the cheapest and easier to install than DELTA robots. Pick and place applications can consist of actions like; transferring workpieces between processes (mounted upright or inversely) or stacking tall workpieces.
They can be used for inspection applications if they have vision systems integrated. SCARA robots can carry out multiple checks including function tests, software evaluations and push button quality checks.
Other applications SCARA robots can carry out include machine tending by loading and unloading workpieces, screw tightening, assembling small parts in a cell or on the line, laser engraving, 3D printing, sorting in a cell and soldering.
What industries do SCARA robots typically work in?
Electrical and Electronics (domestic and industrial)
Handling small electronic components
Handling delicate wafers
Placing components into PCB’s
Food and Beverage
Metals and Machinery
Precision Engineering and Optics