Compact, affordable cobots are a user-friendly way to get more out of your CNC machines. Learn how cobots impact manufacturing.
Collaborative robots, also known as cobots, are becoming more and more common in small to medium manufacturing settings. That’s because unlike traditional industrial robots, cobots are easy to install and implement, capable of working side by side with people safely, and can take on the most repetitive and error-prone tasks.
If manufacturing automation has always seemed out of reach for your company, keep reading. You just might change your outlook!
Implementing Cobots for the Greatest Impact on Manufacturing
Cobots are smaller and more affordable than their industrial robot cousins but are still an investment, so you need a solid plan to get the highest possible ROI. Usually, this means placing them where your production suffers from bottlenecks, jobs that are hard to fill, or where dull, repetitive, error-prone tasks impact quality.
One of the most powerful ways to use cobots is pairing them with CNC machines. Commonly in use since the 1970s, CNC machines are nearly ubiquitous in manufacturing facilities of all sizes. They’re often a safer option for workers than manual material removal and metal shaping and forming, decidedly faster than manual processes, and offer superior repeatability and precision from computer-controlled tooling. The most common CNC machines include lathes, mills, laser cutters and welders, grinding applications, arc welding, and winding.
But until recently, they still required human operators to tend them and oversee the flow of parts. Cobots are changing that by taking on machine tending tasks.
Just as CNC machines make metalworking operations more efficient and productive, cobots make CNC machines themselves even more effective. For example:
Throughput increases. Steady, uninterrupted movements add up over time. Because a cobot moves at a consistent rate of speed, takes no breaks, has no distractions, and is not susceptible to downtime as with a human operator, more parts are machined over the course of a shift, day, or week.
Consistent loading improves quality. A cobot makes the same movements each cycle. So as long as fixtures, locations, and parts remain constant, each part lines up the same way to achieve proper tolerances and specs.
Cobots keep the spindle turning. Parts are loaded and unloaded without breaks or delays, so the CNC machine runs more often and produces a higher-volume of parts and greater flow to downstream operations.
How Cobots Handle the Details of Your Application
Like a CNC machine, a cobot stores detailed instructions in its computerized memory so it can perform tasks correctly. The great advantage cobots have over traditional industrial robots is the ease with which you can give them work instructions. Rather than relying on an integrator to build and program a custom machine, cobots put your operators in control.
The teachable technology cobots use make it fast and simple to show the cobot exactly what you want it to do by moving it through each step and saving them with a graphical user interface (GUI) based app.
The first step is to decide what the cobot will do, then break this job into steps and movements the arm needs to make. It’s important to note each detail of the process because the cobot cannot intuit or fill in any missing steps on its own.
For example, when loading a CNC mill, a cobot may need to perform these steps:
Open CNC machine door (e.g., grasp or hook the handle, rotate the arm to pull the door open)
Rotate arm to move gripper to a tray of blanks
Pick up the blank (e.g., open gripper, grasp blank, close gripper)
Rotate arm to move blank to fixture inside milling machine
Insert blank into fixture
Move arm outside machine
Close CNC machine door (e.g., grasp or hook the handle, rotate the arm to pull the door closed)
Rotate arm and align gripper to press start button
Wait for signal from CNC machine that cycle is complete
Then these steps are reversed to unload the finished workpiece and place it on a tray or conveyor, and the cycle begins again.
In addition to the physical steps of the process, work instructions must take into account known obstacles or special patterns of movement the cobot will need to navigate. These include physical space limits (i.e. walls) or things it must reach around, between, or through to do its work. Remember also that you’ll need to teach the cobot in its actual work location so it can learn the precise distances it is moving and sizes of parts it grasps.
Cobots Benefit Your Manufacturing Workforce
Cobots make great coworkers for CNC machines and human employees too.
While a cobot can run unattended for hours at a time, it’s also safe enough for humans to be nearby, even to work side-by-side, without guarding or safety fencing. Special power and force limiting design means a cobot moves more slowly than an industrial robot, and includes sensors that anticipate collisions and avoid pinching limbs. They are also designed to be compact, smooth, and cool to the touch at all times.
But these on-board safety features don’t limit their physical capabilities. With six or seven axes of motion, cobot arms can perform all the actions a person’s arm makes without tiring or stopping. Several options for reach (i.e. distance the arm extends) and payload (i.e. weight the arm can lift, including tooling) are available as well.
The advantage for workers is better ergonomics on the job because the cobot takes on the repetitive movements like bending, twisting, lifting, and standing in the same spot for hours at a time. Workers also benefit from being able to leave the CNC machine area, which reduces their exposure to dust, chips, heat, and bright light from a laser or welder.
Implementing cobots can also lead to higher job satisfaction and retention. Teaching and overseeing a cobot can be more interesting than tending a CNC machine.
Operations managers may also choose to assign workers to higher-level or more critical manual tasks since a cobot and CNC machine pair can run for long stretches without attention. This allows operators to check in on them while still spending most of their time on other work.