There are four variables to consider when choosing how many fingers your gripper may need.
Choosing the Number of Fingers for Your Soft Robotics Gripper
Please note the below are best practice tips to provide you with the best gripper selection
SIZE: In general, the more fingers you can use to handle your product, the better. In the case of a bagel, a 4 or 5 Finger EOAT is best as all 4/5 will fit around the entire bagel. A pen is a great example of a smaller product that would likely require just 2 Fingers.
SHAPE: If a product has more of a square, or circular form factor an EOAT with between 2 and 5 Fingers would be most effective. A product that has more of a rectangular or elliptical form factor would require between 4 and 6 Fingers.
STRUCTURE: Products such as a pen or a dinner roll have enough structure to support their own weight when grasped and will not collapse when gripped. These products would require fewer Fingers compared to a bag of pretzels, which would require more Fingers to support the collapsible structure of the bagged item.
MASS: If a product has a lower mass, fewer Fingers can be used. As the mass of the product increases, the number of Fingers may also need to increase to support the product.