Introduction: The demand for smaller, more powerful, and increasingly functional devices continues to surge, spanning a wide range of applications—from implantable medical devices (such as pacemakers and miniaturized hearing aids) to non-invasive surgical tools and consumer electronics (like
smartwatches). However, this trend toward miniaturization presents a challenge: how can we efficiently assemble and manufacture these intricate and delicate devices on a large-scale production level?
Automate assembly methods require parts to be singulated such that they can be introduced into the assembly process in the correct orientation. Many of the part singulation methodologies like b bowl feeder are designed for larger components, often cannot perform within the tight tolerances required by microscale intricate parts. This has spurred the development of innovative solutions for part presentation for automation solutions.
In this article we highlight a robotic assisted flex feeder as one solution IST precision has used to help with orienting small parts and placing them into an automation work cell for assembly purposes.
Micro assembly Challenges: Handling and Feeding Miniature Components
A core challenge in micro assembly is the efficient and precise feeding of components to robotic grippers for placement within a processing work cell. As components shrink in size, manual manipulation becomes increasingly difficult and error-prone, necessitating a shift towards automation. However, automating the handling of these miniature components presents its own set of challenges.
Parts often arrive in bulk quantities (e.g., bags or bins containing thousands of tiny parts), which can stick together due to electrostatic forces and other attractive forces. These forces make it difficult to separate and orient the parts correctly for robotic picking.
Traditionally, automation integrators would look to vibratory bowl feeders to assist in robotic pick and place. Bowl feeders operate on the principle of vibratory motion to feed and orient parts. The inside of the bowl is lined with a custom-designed track that spirals upwards. Parts within the bowl are agitated by the vibration, causing them to move along this track. As the parts ascend, the track’s geometry guides them into a single file line, a process referred to as part singulation. This ensures that parts are presented to the pick-up point in a consistent and predictable orientation. However, the traditional design and manufacturing methods for these custom tracks pose significant challenges when dealing with miniature components.
Flex Feeders: A Different Methodology in Robotic Part Feeding
IST Precision has used a type of feeder, known as a flex feeder which offers a departure from traditional part feeding methods. As opposed to relying solely on mechanical tracks and gravity, flex feeders, such as those developed by Asyril, leverage a combination of intelligent vibration and precision vision technology to manipulate and orient parts. This innovative approach transforms the feeding process, offering enhanced flexibility and control, particularly for the challenges posed by the need to orient small parts for micro assembly.
As illustrated below, a flex feeder system typically comprises a bulk feeder and a vibrating tray. The bulk feeder, initially filled with a large quantity of parts typically poured out of a bag, utilizes controlled vibration to dispense a precise number of components onto the vibrating tray. A camera monitors this process, ensuring accurate part counts and preventing overfilling. The vibrating tray then employs a series of carefully programmed vibrations to manipulate the parts. Generated by piezoelectric actuators, these vibrations can be precisely controlled in terms of frequency, amplitude, and direction across the tray surface. This enables gentle separation, orientation, and positioning of even the most delicate micro-components. Furthermore, the tray can be custom designed with features like pockets to facilitate specific orientations, such as aligning small pins vertically for efficient picking. Additionally, by adjusting the vibration intensity, parts can be flipped or repositioned as needed. This dynamic and adaptable approach to part feeding offers significant advantages over traditional methods, particularly for the stringent demands of orienting small parts for micro assembly, where precision, flexibility, and gentle handling are essential.
Advantages and Disadvantages of Flex Feeders
Flex feeders offer distinct advantages over traditional bowl feeders for orienting microscale parts. Their simplified design eliminates the need for intricate tracks, making them significantly more suitable for handling micro-sized parts. Furthermore, the controlled vibration within the flex feeder can overcome electrostatic forces, separating parts for easier robotic pick-up. A key advantage of flex feeders is their adaptability; a single system can be used for a range of parts by simply swapping out the vibrating tray. This flexibility makes them a versatile solution for diverse part geometries.
However, flex feeders do have some drawbacks. Primarily, the upfront cost is higher than that of traditional bowl feeders. This is attributed to the inclusion of advanced components like cameras and the need for customized programming to optimize part feeding and orientation. Additionally, throughput can be a concern, as bowl feeders generally offer higher speeds. However, as previously discussed, bowl feeders can be challenging to implement effectively for microscale parts. To address throughput concerns, multiple flex feeders can be integrated into a system, although this increases both cost and complexity. While the initial investment is higher, the flexibility and reliability of flex feeders can be crucial for successful microscale automation, especially when dealing with delicate and intricate components.
In summary, flex feeders offer a compelling solution for orienting microscale parts for automation, providing benefits in terms of adaptability, part separation, and gentle handling. While the upfront cost and throughput considerations need to be weighed, the overall advantages make them a valuable tool for achieving efficient and reliable microscale automation.
IST’s Experience with Flex Feeders
IST’s automation team has successfully integrated flex feeders into a recent automation system, as pictured below. The Asyril bulk feeder, visible on the machine’s exterior, is where operators load large quantities of microscale parts. These parts are then automatically fed into the machine’s interior, where a vision system monitors their orientation and separation. A Fanuc SCARA robot subsequently picks and places the parts precisely into the processing work cell for further operations.
There are certainly other vibrating flex feeder systems but what sets Asyril apart is their 3-axis vibration technology which enables parts to be intentionally moved in all directions on the vibrating plate with sufficient energy to controllably flip the parts over. This degree of flexibility in multi-axis vibration is why we selected Asyril for this project.
Conclusion
While bowl feeders have long served as a reliable part-feeding solution across various industries, their limitations in handling small, delicate components can make them less suitable for microscale automation applications. In contrast, flex feeders offer a more fitting and efficient solution, provided that integrators consider their higher upfront cost and potential throughput limitations.
IST Precision possesses expertise in precision automation and has direct experience with various vibratory feeding technologies, including Asyril flex feeders. We know how to strike a balance between cost and performance, and we are well-equipped to assist you in evaluating and implementing the optimal feeding solution for your microscale and precision automation needs. Contact us to explore how we can support your manufacturing goals.
