Robots at work

Midmark Corporation takes pride in their new line of in house made, manual examination tables. The idea for this new product was brought up by the company's marketing team back in 2003. The new tables would have big shoes to fill, replacing the previous line, which had been a staple in the healthcare industry since their debut in the 70's.

With the goal of engineering a cost-effective method for creating the cabinet components for this new table, and with a highly innovative design plan in hand, Midmark's fabrication team got to work. The design brought heavy challenges for both the fabrication team and the metal forming team. Knowing that they would have to develop the tools and processes necessary for the completion of this project, Rick Turner, Midmark's engineering manager and project team leader, opened his mind to a brand new concept: robots. In order to fulfill the challenging goal set before him and his team, Turner decided that robotic resistance welding would be the best concept for this task. Along with the assistance of Motoman, Inc.,West Carrollton, OH, Midmark had its system of robots installed in June 2005.

It didn't take long to see how quickly these robots worked. Midmark's new Motoman-integrated robotic welding cell assembles cabinets at a cycle time of 330 seconds (5.5 minutes). Imagine adding fixtures to seven formed metal components, creating 58 spot welds, removing a 55 pound welded cabinet, loading it onto a gravity-fed conveyor and delivering it to a paint line, in just 330 seconds. On top of the excellent cycle time, this robotic welding system made it possible to minimize the number of parts in each cabinet from 16 components and 34 fasteners down to 7 components all welded together.

This amazing reduction in parts was a little too good to be true, placing heavy demand on both the tooling and the metal-forming engineers. In order to fill the immense demand of engineering the intricate operations for these complex parts, they called in for back up. AutoForm Engineering, Troy, MI, lent their helping hand in the form of simulation software. The software's custom-developed blanks allowed the team to draw finished parts in just one hit with no need for trimming.

The cabinet's seven components meet up and come together in the robotic welding cell. This welding cell is where the Motoman ES165 "Expert Spot" welding robot calls home. This robot is decked out with 165 kg. payload capacity, 2,651 mm. reach and a work envelope that extends behind its body. Weld-gun cables, as well as water and air lines, go directly through the robot's base and upper arm into its wrist, giving Midmark's robot full range of motion. This way, it can easily reach each and every spot-weld location with its C-style servo-electric welding gun.

Humans haven't been completely eliminated from this complex process; Midmark workers have added their touch by programming the electrodes in the robot's welding gun. This programmed detail comes through in the robot's welding application, providing it with a gentle touch at impact. This gentle, human-like, touch is ideal and critical to the success of the welding project, giving the examination tables dent-free and mark-free welds. Within a 2 to 3 week period, Turner's team and Motoman put the finishing touches on their very skilled robot, developing a motion routine for it to follow. Following this routine, Midmark's robot can do its work without interference. Midmark and its robots work hand and hand, providing smooth sailing for the production of its new line of manual examination tables. "Dropping our old table line over a 30 day period and launching this new table design has been remarkable. The table has done well in the marketplace and our team continues to do well with the project. Motoman's support helped make it happen," summarizes Turner.