Types of Machining robots

When choosing a robot for machining tasks, you've got options. The four main types are Articulated, Cartesian, SCARA, and Parallel robots. All of these options are called “robot arms” in the industry, but when you picture a robot arm, you’re likely just thinking of an Articulated robot.

• Articulated robots have rotary joints that move much like human arms. They're very flexible in high-mix scenarios and can reach tricky angles at the cost of being less precise. Good for drilling, cutting, polishing, and assembly. 
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• Cartesian robots move along three linear axes, so they're precise but limited to straight-line movements. They can easily be affixed to tracks on a ceiling to save on cell floor space. Great for precision machining like routing, cutting, and grinding.
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• SCARA robots have two parallel rotary joints and can move very quickly on a horizontal axis. They're faster than Cartesian robots, more precise than most Articulated arms, and often the most compact choice. They’re ideal for pick-and-place, packaging and polishing. 
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• Parallel robots have a fixed base and moving platform connected by multiple arms. They're the most rigid and precise option but complex to program. Used for high-speed, high-precision machining, especially on complicated conveyor production lines.

In choosing a robot, pay particular attention to the working area available in your shop and the size of the parts you require it to work with. Articulated and SCARA robots work best for small parts and tight cells. Cartesian and Parallel robots can handle larger, heavier parts but often require more setup, such as ceiling tracks and are therefore less adaptable. Precision and speed are key for machining, so you’ll want to look out for the robot's “repeatability” — how accurately it can return to a position over and over again.

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End-effectors and tooling for Machining robots

With your robot chosen, the next important choice is the end-of-arm-tooling. These “end-effectors” are what allow your robot to interact with the environment around it and dictate the types of tasks your robot can undertake. Here are a few of the most common options for machining:

Grippers

If you need to pick and place parts or manipulate objects, a multi-fingered gripper end-effector is a good choice. Grippers can grasp parts of various shapes and sizes. Basic grippers will look much like a workbench clamp or a human hand. More advanced examples include Vacuum grippers which use suction to pick up smooth, non-porous parts. Magnetic grippers are ideal for handling ferrous metal parts, while Needle grippers can pierce and move fabric.

Welding equipment

For welding applications, a welding torch end-effector can be attached to a Machining robot. The robot can then perform arc welding, spot welding, laser welding and more. The welding torch may need to be customized based on the specific welding process and a higher payload robot is often required to handle heavy cables for shielding gas and electrodes. 

Cutting and polishing tools

To cut, grind, deburr, polish or sand parts, a Machining robot can be fitted with rotary cutting tools like saws, grinders, sanders and deburring tools. The spindle speed and power need to match the requirements of the cutting tool. A coolant system is often necessary to prevent overheating, and you may consider an end-effector with a built-in vacuum to reduce mess or a grit-changer to reduce human intervention. 

Drills and fastening tools

For assembly tasks like drilling, screwing, riveting or inserting fasteners, the appropriate driver bit or drill chuck can be attached to the robot arm. These include nut drivers, screwdrivers, drill chucks, and riveting tools. You’ll want an end-effector with a built-in torque or force sensor to ensure your robots don’t over-tighten fastenings. 

Other options

End-of-arm-tooling exists for almost any application you can think of. If there’s a tool which can be manipulated by a human, then a robotic adaption almost certainly exists. End-effectors exist for chiseling, gluing, nail-gunning, and even cutting materials with scissors. If you’re looking for a particularly niche end-effector, your robot’s manufacturer will be able to point you in the right direction.

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Factors to consider when choosing a Machining robot

When choosing a Machining robot, there are several factors you should consider to determine which type is right for your manufacturing shop. We’ve already considered the specific types of robots you should look at and the importance of end-effectors. But you’ll also want to consider the work envelope, speed, safety factors, and cost.

A robot’s work envelope refers to the area it can reach. A larger envelope means a bigger range of motion to access your parts or move them around. This does often come at the cost of precision and even more often, speed. Think about the sizes of parts you need to handle and the tightness of workspaces. 

Speed is also an important factor. This is both inherent in the type of robot you choose such as a SCARA robot which has fewer joints to individually move than an Articulated arm and therefore can generally move faster. The RO1 by Standard Bots can outpace most robots with a joint rotation speed of 435 degrees per second. 

While small differences in speed can seem trivial, higher joint movement means faster cycle times, which translates to more output from your robots and a higher ROI. 

Safety is your next consideration if you’re going to operate a fast-moving robot equipped with a sharp tool. You’ll want to consider a “Collaborative Robot” — that is, a robot equipped with built-in safety sensors and collision detection for safely working alongside humans. 

For more dangerous situations, like lifting heavy payloads or equipping a robot with a cutting device, your risk assessment may necessitate additional safety equipment like a fence, proximity sensor or emergency-stop buttons.

Your budget is another important factor to consider. Machining robots can cost anywhere from $35,000 to $400,000 or more depending on the type, brand, and accessories. While cost is always a factor, choosing a robot that can’t perform the necessary tasks efficiently will cost more in the long run. You’ll want to consider additional costs depending on your choice of robot and process, such as retooling or programming costs, which can vary wildly depending on the robot. 

Top Machining robot manufacturers

When it comes to choosing a robot for your machining needs, you have several reputable manufacturers to consider. Here are some of the top players in the field and what they offer.

ABB

ABB is a Swiss pioneer in robotics and automation, with over 300,000 robots installed worldwide. They offer a wide range of Articulated, SCARA, and Cartesian coordinate robots suitable for machining applications like welding, cutting, deburring, grinding, and polishing. Their higher payload robots like the IRB 6700 or IRB 7600 are well-suited for heavy machining tasks.

FANUC

FANUC is one of the largest Japanese robotics companies, with over 4 million CNC’s and 400,000 robots installed globally. They provide highly reliable robots for machining, including their FANUC M-710iC/50H and M-20iA/12L models. These Six-Axis, high-speed robots can perform precision machining operations like deburring, grinding, polishing, and dispensing sealants.

Standard Bots

Standard Bots are a US-based robotics company with a manufacturing facility based out of New York. Their flagship Articulated Arm RO1 possesses the largest payload at 18 kg in its class, with the fastest joint movement and most accurate repeatability amongst competing robots. RO1 can integrate particularly easily with OnRobot machining end-effectors and pricing begins at $5 per hour of operation.

Yaskawa Motoman

Yaskawa Motoman produces innovative Industrial robots for various machining applications like spot welding, arc welding, cutting, and dispensing. Their high-speed, space-saving robots like the Motoman GP8 and GP12 are well-suited for machine tending and parts transfer. They also offer the Motoman MH24, a heavy-duty robot designed for demanding welding and cutting operations.

No matter the manufacturer you choose, each will be able to help you figure out your full robotics solution, including the most suitable robot type, compatible end-effectors, appropriate accessories like conveyors and safety features like proximity sensors. 

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Next steps

So there you have it, the basics of choosing a Machining robot for your factory floor. Do your own exploring, and think about what kinds of parts and materials you want to work with first and how quickly you need to produce them. With your budget in mind, you can narrow down your options and find a robot that will help streamline your processes, reduce costs in the long run, and boost your productivity and profits. With so many options available now for even the smallest of operations, getting automated is more feasible than ever.

Interested in bringing robotic Machining to your own business? RO1 by Standard Bots is the best choice for machine shops large and small:

1. Affordable: RO1 is the most affordable robotic arm in its class, starting at almost half the price of incumbent competitors. 
2. Powerful: RO1 is faster and more precise than competitors, despite having the highest payload capacity in its class at 18 kg.
3. Integrated: RO1 comes equipped with built-in relays to control almost any machine on the market, including plug-and-play support for Haas CNC milling machines.

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Speak to our solutions team today to organize a free, 30-day onsite trial and get expert advice on everything you need to deploy your first robot.