What is a cobot and why should CNC machine shops consider them? Learn about the benefits and applications of cobots for CNC machining.
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What is a Cobot?
Collaborative robots, or “cobots”, are growing in popularity in manufacturing and industrial settings, particularly in machine shops. Unlike traditional robots, cobots work safely around people and do not need to be enclosed behind a barrier or safety fencing. Due to their built in safety features, cobots work collaboratively with their human counterparts, assisting in tasks and taking on the repetitive, mundane, and dull work. In machine shops, cobots tend machines all day and night. They keep the “spindle turning” by loading and unloading parts consistently without breaks, increasing throughput and reducing machine idle time.
Cobots are vastly different from traditional industrial robots associated with large factories and assembly lines. They are smaller, less expensive, and more flexible. Cobots differ from traditional robots in the following ways:
Safety. Cobots do not require safety fencing or other barriers and can share workspaces with humans. They have built in safety features that make them slow down or stop completely if a human comes into its work area.
Flexibility. Cobot arms have the flexibility to handle various tasks. They are not limited to a single task or operation and can be redeployed as needed. Cobots can roll between different machines on a shop floor and tend two machines at once.
Ease of use. Cobots are easier to program than traditional robots. The latest generation of cobots like Productive Robotics' OB7 require no programming at all and can be “taught” tasks by physically showing them what to do.
Cobots vary in size and specifications for handling a wide range of parts. Machine shops can choose the most suitable cobot depending on their part sizes and their machine cell environment.
Payload and reach. The payload of a cobot is the weight that the robot arm can lift. Cobots have a range of maximum weights. The reach of a cobot is the distance that the robot arm can reach. If you want to tend two machines for example, you will need a robot arm that has a longer reach to accommodate both machines.
Articulated arm and joints. Cobot arms provide flexibility for tending CNC machines and handling a wide range of industrial tasks. With seven axes of movement, an OB7 cobot has a unique advantage in a CNC machine tending environment. It can reach around the CNC machine and load parts without blocking access for the operator, which is not possible with a six-axis cobot. In addition, OB7's seven-axis motion allows it to reach around obstacles and fit into tighter spaces.
Collaborative Robots Working with Machine Operators
Cobots are becoming increasingly popular in machine shops because they are perfectly suited for handling machine tending tasks. Just like a human, cobots load and unload machines, but they don’t take breaks, get sick, or go on vacation. Cobots take on the tedious, repetitive, and error-prone tasks that workers find monotonous, or that contribute to bottlenecks in production. By taking on the machine tending process, cobots maximize spindle utilization and free up operators to handle other valuable tasks.
Cobots Offer Simplicity and Value in Manufacturing
Many cobots offer “easy programming” but still require a programming language that is difficult for those who have no programming experience. Cobots like OB7 from Productive Robotics require no programming at all, making it easy for machine operators. They simply “show” it what to do and the cobot learns. It can take a few hours to set up a machine tending cell and begin automating on the same day.
So what does a cobot do exactly when it tends a machine? Cobots handle the “repetitive” tasks that a machine operator normally does, such as:
Opening and closing a machine door
Loading and unloading blanks or parts
Staging material for processing or inspection
Recording pertinent data
Deburring, polishing, grinding
Whether you are running thousands of parts or as little as 5 parts, a cobot keeps your machines running consistently until the job is done. Operators can then shift their focus to work on other tasks like post-CNC quality inspection or setting up new jobs. Cobots don’t need a break and can work "lights out", making chips after you go home for the night.
Machine Compatibility and Set Up
Cobots can tend all types of machines, including mills, lathes, presses, EDMs, plasma cutters, grinders, and presses. Next generation cobots like OB7 from Productive Robotics can work with any brand of machine without interfacing into the machine, making the setup process simple and fast. OB7 cobots also have 7 axes or degrees of freedom (like a human arm) which provide a key advantage for machine shops:
Flexibility to reach around doors and into machines: A cobot like OB7 that has 7 axes provides a unique benefit for machine tending. The cobot can be placed to the side of the machine door and reach around and into the machine to load the part without blocking access for the machine operator. This is due to the extra flexibility and dexterity of the 7th axis, which is not possible with a 6 axis cobot
Many cobots come with robot stands that have wheels, allowing you to roll the cobot and position it in front of a CNC mill, lathe, or other machine to load blanks and unload finished parts. Material is staged on a worktable for the robot to pick up and load into the machine. Many machine shops use their own equipment to create custom tooling, fixturing, and end-of-arm tooling as well.
Productive Robotics offers mill and lathe packages that include all of the robot accessories necessary to work with your machines. This simple solution eliminates the need for complex integration and works with all types of machines.
Large Runs or High Mix/Low Volume
It’s easy to understand the value that cobots bring to CNC machining operations for running high volume jobs. Cobots keep the spindle turning without breaks, and they can even run unattended overnight and weekends for “lights out” manufacturing capabilities. But what if you don’t have high runs or if you do custom work? Can you still benefit from cobots? The answer is yes.
Cobots shine in high mix/low volume environments as well, and many small to midsize machine shops are using them to their advantage. A great benefit of cobots is their flexibility and ability to move between different machines. For example, if you are running a job of 10 parts with a long cycle time, the cobot can complete that job and free up your operator until it’s done. You can then run the robot on a different job in a matter of minutes.
Cobots also reduce idle machine time by working on second ops that involve longer cycle times. Their small footprint and flexibility make them as useful in high-mix, low-volume (HMLV) environments as they are in low-mix, high-volume (LMHV) environments.
Loading CNC Machines with Cobots
Cobots can be equipped with a range of grippers that are suitable for picking up all types of materials, from metal, to composites, to high-density polymers, to sheet materials.
Tooling options. End-of-arm tooling or grippers are the “fingers'' that the robot uses to pick up parts. These can be electric, pneumatic, or custom-made to handle various items and workpiece materials. There are a range of tooling options that can be used to pick up parts of different sizes. They can also handle delicate materials and small items.
Dual Grippers: A dual gripper is another time saving option that allows you to speed up production by using two grippers in one. With a dual gripper, you can unload a completed part then immediately reload a new part, eliminating the extra trip to and from the machine. This is great for tending a lathe and allows you to reduce machine wait time during part reloading, which can greatly reduce cycle time. See video: Dual Grippers
Productive Robotics manufactures its own cobot grippers and dual grippers. In addition, all cobots from Productive Robotics are compatible with other end-of-arm tooling options on the market.
The Top 4 Benefits of Cobots for CNC Machines
Robotic machine tending provides many advantages for machine shops of all sizes, including lights out production, improved part quality, and operator productivity. Below are some of the key benefits that cobots provide:
1. Boosting CNC Machine Productivity
Throughput and Optimizing Machine Run Time
When machine shops think of productivity, they think of throughput. In a typical 8 hour shift, a person can run a job of 20 parts that takes the entire shift to complete. They get distracted or have multiple responsibilities that deter their focus, letting the machine sit idle. With a cobot, machine idle time is eliminated, and machines run at maximum capacity. By working consistently, unattended, cobots maximize throughput while increasing productivity.
Quality, Accuracy, and Consistency
Improved part quality is a top priority for machine shops. Cobots complete tasks consistently with accuracy and precision, minimizing defects due to misloading blanks caused by operator fatigue or distraction. Part quality as well as operator productivity is increased.
Reducing Repetitive Manual Tasks
Business owners understand that an operator’s time is better spent on the work that requires human skill and experience. By letting cobots take on the redundant, repetitive, and mind-numbing tasks, operators can do work that is more challenging, interesting, and varied.
2. Cobots Can Shift to New Processes with Ease
With greater flexibility and portability, cobots can seamlessly integrate into existing workstations. The newest generation of collaborative robots make it simple for in-house staff to set up and roll the cobot between different machines.
Quick and Easy Cobot Deployment
In-house staff can set up an OB7 cobot from Productive Robotics in a few hours - no outside integrator necessary. Simply plug it in, move it into position, and “teach” it the necessary motions.
Most collaborative robots are programmed with traditional robot programming. Others offer “easy programming” or simple coding. OB7 cobots are the latest generation of cobots and require no programming or coding at all. They are "taught" their tasks from you as you show them each step. While simple by design, these cobots are highly intuitive and can handle complex CNC machining jobs with precision and quality.
Teachability. If you can teach a human how to load a CNC machine, you can teach an OB7 cobot how to do it too. “Teaching” requires physically showing the cobot what to do by moving the arm using the control handle. There is no coding or computer programming skills required. This kind of simple teaching makes it easy for anyone to operate, irrespective of their experience level.
3. Safety and Flexible Automation
CNC Robots Protect Workers and Save Space
Built-in safety. Cobots are designed with safety in mind. They include power and force limiting features that tell the robot to stop or slow down if a person is approaching. These safety features reduce injury and minimize risk. Cobots can also run at higher speeds and switch to safe collaborative speeds when a human enters its work area.
Compact footprint. Lightweight, flexible, and small, cobots don’t take up much floor space. They are compact enough to fit in shop floors and can be mounted to a tabletop, cart, floor, or ceiling. Cobots like OB7 offer extra 7 axis flexibility to reach around objects and get into tighter spaces.
Portability and flexibility. Many cobots come with rolling stands, which allow them to move easily between machines. There’s no need for complex re-engineering of your manufacturing equipment, and no time-consuming integration work.
4. Lower Costs
Cobots are less expensive than traditional industrial robots. They do not require expensive safety equipment or the high costs of hiring an automation integrator. Cobots from Productive Robotics are also the most cost-effective because they are designed and manufactured in the USA. A cobot package from Productive Robotics comes complete with all of the components needed to integrate a robot into your machining cell.
ROI and Machine Payback Period
By maximizing machine runtime or uptime, a cobot provides fast return on investment. Lights out production also opens up the door for businesses to take on more work, increasing their bottom line and gaining a competitive advantage. Other factors can impact ROI such as payroll costs and ability to scale up production. Since every business is unique, it's always best to calculate your own ROI to understand the costs and savings.
Frequently Asked Questions About Collaborative Robots
How Will Cobots Impact My Employees?
Cobots and humans work collaboratively together in a shared environment that enhances production efficiency and productivity. When adding a cobot to a workstation, employees quickly discover that it gives them more time to do the interesting and challenging parts of their job, or to learn new skills entirely. Teaching the cobot to do different tasks and discovering all its potential uses also leads people to come up with new and interesting ways to use it to help with other tasks.
Cobots are Designed with Human Interaction in Mind
Better ergonomics. When a cobot does the repetitive movement (lifting, bending, and twisting), ergonomics improve, and fatigue is reduced.
Physical safety. In addition to sensors that slow or stop the arm when a person or limb approaches, cobots are manufactured with rounded corners and no pinch points, keeping workers safe, even when the machine is not moving.
Which Types of Manufacturing are Cobots Good For?
Cobots are not limited to CNC machine tending. They can do a wide range of manufacturing tasks that involve repeatable movements and require accuracy and precision. Common tasks that a cobot can handle include:
Laser and plasma cutting
Other common industrial tasks include:
Getting Started with Cobot Automation for CNC Machines
Learn more about machine tending with cobots:
Download our free ebook: Robotic Integration for Machine Shops
Check out our video resources to see more examples of cobots in action with CNC machines.
Review case studies from machine shops who are gaining competitive advantage with cobots.
Register for one of our upcoming webinars or events to see OB7 in action.
Interested in an application evaluation? Contact us today to speak with a robot expert and get a hands on demo. Contact us today!