We’ve come a long way since Rossum’s Universal Robots. Robots today are rising in every industry, from manufacturing to agriculture to warehousing and logistics. Such robots are tasked with delicate, dangerous, and demanding tasks which require power and precision. As such, companies manufacturing robots must build to careful specifications to make certain the robots are capable of carrying out their duties in the field and factory.
Robotics assembly requires the use of many fasteners of assorted sizes, from tiny screws to heavy bolts. Each fastener will have an ideal torque range. For the robot to perform up to specification, manufacturers must deliver the right amount of torque to each screw, nut, and bolt during assembly. Improper amounts of torque can lead to assembly failure, potentially causing the robot to fail at its task. Especially for smaller fasteners with narrow torque ranges, modern robotics manufacturers must invest in precise torque control for their assemblies.
Why Robotics Assembly Requires Precise Torque Control
Robots across industry lines are designed to perform under stress. The tasks they are programmed for, from lifting boxes to boring subway tunnels, exert significant force on robotic parts over time. In order to hold up under the stress, robots must be assembled according to the engineer’s specifications for fastener torque. If either too much or too little torque has been applied to any fastener, it will be more likely to deform, warp, shear, or rattle loose.
Smaller robotics applications are likewise subjected to the stresses of rapid movement and long hours of operation. Their small fasteners have narrow ranges of ideal torque conditions, necessitating the utmost precision in their assembly.
Both large and small robots are depended on for financial success and worker safety in the fields that employ them. A large robot can be the bottleneck in a manufacturing facility, mining operation, or farm. When the robot goes down, a percentage or all of the business’s operations can grind to a halt. If people work in close proximity to the robot, its failure can potentially put them in harm’s way.
For smaller robots used to manufacture other products or perform autonomous tasks in the field, failure can be no less costly. The rapid assembly of consumer, automotive, aerospace, medical, and other products requires stringent quality assurance procedures. Malfunctioning assembly robots can cause lost product or bottleneck an assembly line if they break down entirely. If a fastener fails in a robot operating in a difficult environment—like the deep sea, the surface of an asteroid, or the rubble of a ruined building—the mission can be compromised, potentially at great expense.
Choosing the Right Torque Tools for Robotics Assembly
In order to successfully manufacture either large or small robots, companies must invest in manufacturing tools capable of limiting torque. Larger fasteners will require more torque while a smaller fastener will need greater precision. Depending on the speed of assembly, hand tools or power tools will be preferred.
When creating large, specialty robotics—such as individual mining machines or self-driving tractors—large, durable fasteners will be required. Powerful torque wrenches must be used to deliver enough torque to appropriately tighten these nuts and bolts. Pneumatic torque wrenches, particularly pulse wrenches, are effective for these applications.
Pulse wrenches generate very little reaction force against their operator, allowing them to be used at higher torque ranges than continuous drive pneumatic tools. At the same time, the speed and power provided by their pneumatic drive are greater than what hand tools can supply. While some click wrenches can generate more torque than a pneumatic tool, they cannot do so as quickly or as accurately.
For smaller robotics assembly, speed and delicacy are far more important than raw power. As such, DC-controlled electric screwdrivers—which themselves can be automated systems—are a top choice for manufacturers. DC-control screwdrivers limit torque by ceasing their movement based on the amount of electric current delivered to their drive. This grants their operators extremely fine control over their torque delivery, including the ability to accomplish soft starts and stops for fragile assemblies. Modern control systems allow these screwdrivers to execute multi-stage fastening operations and track each fastener delivered to ensure none are omitted, cross-threaded, or unfinished. Nothing says cutting edge like robots building robots.
From the tiniest swarm drones to large automated aircraft, robots rely on their fasteners. In turn, robotics manufacturers must rely on their torque tools to set each fastener to just the right tightness. Large robots and large bolts require powerful, accurate pneumatic tools while smaller robots require the speed of electric screwdrivers. Either way, precision is the name of the game when it comes to torque control for robotics assembly.