Shoals Technologies Group (Muscle Shoals, AL) manufactures custom automotive parts as well as appliance and industrial components. These components include wire assemblies and electromechanical devices. To facilitate larger production runs, the company worked with Hanson Systems Inc. (Fletcher, NC) to create an automated resistance welding machine.

In building the machine, Hanson Systems incorporated a number of Robo Cylinder electric actuators from IAI America Inc. (Torrance, CA), both to lower ramp-up times and increase the accuracy of the welds.

According to Hanson Systems, this was the first time the company had used an electric actuator in a resistance welding machine. Previously, because of the costs involved, the company had opted for pneumatic actuators. But with prices coming down for electric systems, the company decided to switch over.

The result has been a machine that is accurate, fully programmable and easy to use. With cycle times of 2.5 seconds, Shoals Technologies is able to produce as many as 8,500 subassemblies per day. Changeovers between products are easier, resulting in shorter downtimes.

"The Robo Cylinder is efficient compared to a pneumatic actuator, and it performs with great accuracy and reliability," says Gary Miller, head manufacturing engineer at Shoals Technologies. "Features like infinite positioning compensate for machine wear and are good for situations where we have to interchange."

He adds that, although electric actuator hardware costs can be slightly higher than that of a pneumatic actuator, the price is more than offset by the ability to control the application.

"The time to debug is shorter, the accuracy and reliability are better, and we can build more flexibility into our designs than with pneumatics," Miller says.

"We powered up, and it performed flawlessly," says Shoals Technologies Group president Dean Solon.

Since installing this first machine, Shoals Technologies has purchased a pair of larger Hanson resistance welding machines employing more than 40 Robo Cylinders. And Hanson Systems has begun using electric actuators for its other customers as well.

Hanson System president Chuck Miller cites the programmable nature of the electric actuators as one of their advantages over pneumatic systems.

"To adjust a pneumatic slide, you use the dial indicator, loosen the nut and fine tune the device to 0.003 inch, a measurement equivalent to a human hair. Fine-tuning requires a half an hour to an hour," he says. "Using the Robo Cylinder, with one keystroke of the computer you can automatically make adjustments."

Chuck Miller also lauds the electrical actuators' decreased setup times, accuracy of position and improved acceleration-deceleration control.

"We plugged it in, applied the power and it started running. No adjustments were needed," he says. "I had been in the business for 31 years and had never seen that happen before. That convinced us that this was the way to go."

For more on electric actuators, visit, call 800-736-1712 or eInquiry 1.

For more on automated welding and assembly equipment, call 828-687-3701, visit or eInquiry 2.

For more on contract assembly and manufacturing, call 256-314-1119, visit or eInquiry 3.