Screws aren’t the easiest things to pick and place. Small screws, the kind often used in electronics assembly, are especially difficult, even for workers with delicate fingers. This is why it pays to use screw feeding or presenting systems. Here’s some information about the options.
An Ergonomic Challenge
If you were using screws for a one-off assembly you’d pick each one out of a box using a pincer grip and insert it into a pre-drilled hole. In some assembly operations, the hole might already be threaded, in which case you’ll need to turn the screw back and forth to start the thread. Then you pick up the screwdriver, engage the bit and drive the screw home.
Now imagine doing that dozen of times per hour for an eight-hour shift. Your hand would quickly cramp up, you’d slow down, and you’d make mistakes. Adding a screw presenter or screw feeding system to the assembly operation overcomes this problem.
Two Types of Screw Presenter
The simplest system is the screw setter or shaker. This is a panel full of holes the diameter of the screw you’re using. Spread the screws over the panel and give it a shake. The screws will settle into the holes, head up, making it easier to pick them up.
The screw presenter is an advance on this. With a hopper capable of holding roughly 200-300 screws, this tool sorts and feeds screws one at a time to a pickup location for the operator to grab. If the screws are ferrous a magnetic screwdriver bit will pick up each one as needed. Stainless or other non-magnetic screws can be picked up by adding a vacuum pickup attachment to one of our torque screwdrivers.
The Automatic Screw Feeder
Like the screw presenters, the screw feeding systems also feature a hopper and rail system that orients and delivers screws one at a time. This device then delivers each screw through a small feed tube directly to the screwdriver tip. Place it, drive it home, and lift up; the next screw is instantly ready to be inserted without the operator having to pick or place a screw. These systems work with either pneumatic or electric-powered screwdrivers, in both push and lever start types. They are also often integrated with a smart 3-axis table for an automated assembly solution.
Use Cases in Manufacturing
The screw shaker is useful in low-volume manufacturing and assembly work. It improves the ergonomics of the job but doesn’t give a big increase in screws driven per hour. Because it puts each screw in the same location, the screw presenter speeds up the assembly task and so raises productivity. Use this in a medium volume assembly operation.
The ultimate in screw automation is the feeder. Delivering each screw right to the screwdriver tip eliminates repeated moves between assembly task and pickup location, so improving assembly efficiency. This is the tool for high-volume assembly work.
Justifying the Investment
The primary gain is the number of screws that can be driven per hour, but there are other benefits too. Eliminating ergonomic problems improves the job and prevents absences due to wrist injuries. Third, less fatigue means fewer mistakes. As one screwdriving mistake can scrap a whole assembly this can be a big saving!
Our experts at Sumake North America can help you decide which screw feeding system is right for your application. Contact Us or call (603) 402-9952.