When is 3D printing interesting for robot grippers?

When designing a robot cell, the balance must always be found between accuracy, speed, payload and of course costs.  

The accuracy, for example, depends on the rigidity of the robot and the inertia of the system. The lower the mass of robot and payload, the smaller the inertia (and overshoot) and the more accurately the cell will operate. The smaller the mass of the payload, the faster the same robot cell can operate in order to achieve the same accuracy. At low speeds, the payload may be high in order to achieve the necessary accuracy.

It is only interesting to change to a lightweight version of a gripper when the weight of the gripper has a large share in the total payload. Useful payload, or the weight of the load moved, is the difference between the total payload of the robot and the weight of the gripper. If the useful payload is high compared to the total payload, a weight reduction of the gripper has little effect on the total payload.

For example, if a load of 700 g is moved with a gripper of 300 g, it makes little sense to rework the design of the gripper to a lightweight version of about 210 g (30% weight reduction). The total payload then remains 910 g (instead of 1000 g, so a 9% total reduction).

However, if a 300 g gripper moves a load of 20 g, the same weight saving has a more significant influence on the total payload: 210 g + 20 g = 230 g (instead of 320 g; thus a total reduction of almost 30 percent). A payload that is 30 percent lower can certainly have an influence on accuracy and speed.

Conclusion

It’s useful to invest engineering time in a lightweight version of a robot grabber for robot cells that move light loads and move quickly. Typical examples are applications in food, pharmaceuticals, electronics, plastic components, etc. 

Are you interested in this topic or looking for a solution for your specific situation? Then please contact us! Sirris has about 20 experts in additive manufacturing and an extensive machine park to help you further.