Many small business owners absorb the idea that automated assembly screw driving is not cost-effective for anyone besides major corporations. Thanks to advancements in automation and robotics, though, automatic screw driving is available for businesses of all sizes. Here’s what small business owners need to know about Schneider & Company’s different automated screw driving processes and their applications.
What Is Assembly Screw Driving?
Assembly screw driving involves screwing different parts together in an assembly process using a threaded fastener. It’s commonly used for multi-component products that cannot use processes like press-fitting, glue, rivets, or welding because they either need to be held together in compression or they are joints that need to be disassembled later. In the past, assembly screw driving involved the operator placing the screw either on the tool bit or starting the threaded fastener by hand. In both cases, the fastener was then tightened using either a pneumatic or electric screwdriver. Over the years improvements in final torque setting were developed as a part of the screwdrivers but the accuracies were somewhat limited by the use of the operator using the hand tool. There were also labor and safety costs from torque and repetitive motions with these processes being done manually.
Now, manufacturers install machines that handle semi-automated or fully automated screw driving directly into their assembly lines. Employees can move their unfinished products into position and set each machine’s torque value, but they are not responsible for the actual screw driving. Because this assembly style is growing more common and more affordable it’s easier for small business owners to increase their productivity and decrease their costs with automated assembly screw driving.
Assembly screw driving is an integral part of almost every kind of high-value product being manufactured. Whether companies create toys, laptops, construction materials, automobiles or medical equipment, they usually need to install screws at some point. It’s also increasingly common to see screwdriving at manufacturers who specialize in processes like stamping or plastic injection molding as secondary and value-added processes.
Many manufacturing companies use pneumatic screwdrivers for their assembly screw driving. These pneumatic tools use vane-type air motors, which deliver high RPM and enough torque to quickly insert screws. There are typically additional components attached to these pneumatic drivers when used manually such as torque arms and tool balancers to protect the operators from injury.
Pneumatic screwdrivers have developed good and accurate means of shutting off the driving process when the fastener has reached a torque limit. These are typically clutch types of mechanisms and are mechanically adjustable and verifiable with the use of a torque transducer.
These types of pneumatic screwdrivers can be used with any level of automation, from manually placed screws as mentioned above or with the addition of automated screw feeding where the operator will drive the screw but not place the screw. Finally, fully automated screwdriving is possible and economical when combining pneumatic screwdriving with screw presenters and low-cost SCARA robots. This offers manufacturing companies of all sizes great flexibility, process assurance in a fully automated and cost-effective solution.
Electric screwdrivers are another option for assembly screw driving. These configurations use a specially built electric motor that can be programmed for speed and final torque. The primary advantage over pneumatic screwdriving is that the process is controllable within a cycle so you can start out at slower RPM, then increase or decrease based on torque-sensing feedback. It is very common in the automotive manufacturing industry to have screwdriving specifications which define a good screw joint in terms of both the final torque and also the degrees of angle to get there from a programmable snug torque.
The earlier versions of Electric or DC screwdriving used very accurate but somewhat expensive torque transducers as a means of measuring the torque; more recently torque measuring strategies are possible from measuring the motor load which offers nearly the same accuracies but at a reduced cost.
Electric DC screwdriving is generally considered more accurate and more controllable than pneumatic, albeit more expensive because of the additional cost of the controller. Like the pneumatic screwdrivers, electric DC screwdrivers can also be used with any level of automation from manual placed screwdriving to manual driving with automated screw feeding or full automated screw feeding and automated or robotic screwdriving.
While using the latest advanced Pneumatic or Electric DC screwdrivers manually is still common there is increasing evidence of automated screwdriving in manufacturing. This is due in part to combining the screw driving equipment with lower-cost alternatives to feeders such as screw presenters and lower-cost alternatives to automation such as SCARA robots. Schneider & Company are experts in the process of screwdriving and offer solutions at every level of automation from standard screwdriving to the unique FDS/FFS used in automotive BIW and the development of their own torque isolation robot screwdriver called SCARA DRIVER II. To view our full list of products, click here.