"The OB7 isn’t just a dummy pick-and-place robot. It gives us analytical data about each part."
Testing and QC
LENKBAR USES OB7 TO LASER ENGRAVE AND INSPECT MEDICAL DRILLS
Jay Clairain, Lenkbar’s director of quality and new product development, left, and Rainer Abello, quality control manager and automation engineer.
Productive Robotics’ teach-by-touch cobots caught the attention of Lenkbar LLC. Based in Naples, Florida, Lenkbar was founded in 2012 as a design company. In 2017, President and CEO Erik Papenfuss took Lenkbar into the medical space as a contract manufacturer with the goal to develop, design and produce surgical devices and implants that simplify surgery for physicians. The orthopedic device specialist manufactures precision medical devices to 0.0001 tolerances. All equipment must adhere to stringent ISO-13485, FDA, OSHA and EPA standards. Products include medical drills, trocars, aspiration devices, orthopedic instrumentation and implants.
“We produce thousands and thousands of products per day because most of these tools are single-use disposable devices,” says Jay Clairain, director of quality and new product development for Lenkbar. “Final inspection was a manual process that employees performed using microscopes. It’s time-consuming when you have 2,000 or 3,000 parts in a single lot.”
Familiar with robotics, Clairain saw several applications that could benefit from the technology. “We have some challenging parts and needed flexibility. Productive Robotics was willing to perform upfront testing to ensure their cobots could meet our requirements. They determined the correct vision system and gave us a very competitive price.”
In May 2021 Lenkbar installed an OB7 Stretch cobot and a Cognex D900 Vision System. “Productive Robotics was willing to partner with us,” Clairain says. “We said, ‘Give us a robot that will work and we’ll figure out the rest.’”
The rest, according to Lenkbar Quality Control Manager and Automation Engineer Rainer Abello, included developing programming for the laser engraving machines the OB7 would feed parts to. Abello started with a medical drill ¼ in. long and 0.04 in. in diameter.
“We are using the OB7 to insert parts into the laser marking equipment and then inspect parts for laser quality and correct information,” he says.
The cobot picks a part up from the pallet, places it in an air chuck, tells the air chuck to open and close and prompts the laser to initiate the engraving sequence. It then moves the part to the vision system for inspection.
“We had a department of four people performing this operation,” Clairain says.
“With the OB7, we’ve reduced the need for human interaction. Instead, we’ve moved those individuals to other areas, retrained them and taught them higher value-added skill sets.”
Positioned between two laser engraving machines, the cobot is able to run parts on both lasers at the same time.
“We’re currently processing 15 different part numbers but we expect to add another 40 or 50 more,” says Clairain.
The OB7 can initiate a time delay or the laser engraver will signal when it finishes a cycle. The cobot then takes the part and presents it to the vision system. In addition to a pass/fail, other variables like which pallet grid the part was pulled from are recorded and saved.
“We only accept quality inspection scores of 95 percent or higher,” says Abello. “If you are consistently running bad parts, you can identify which grid location they are from. The OB7 isn’t just a dummy pick-and-place robot. It gives us analytical data about each part.”
The cobot has helped Lenkbar recoup cycle time. “We found there was a lot of wasted time with operators,” continues Abello. “They get distracted, take breaks, go to lunch. The cobot doesn’t need to stop for any of those things. The laser engraving machines are running lights out six days a week for at least 20 hours. We’re looking at sourcing an automatic feeder that can hold 10,000 parts at a time.”
Each of the OB7’s joints can rotate 360 degrees in both directions. The cobot can sense collisions at every joint, a function that triggers a safety stop. The OB7 can also be stopped with an operator’s hand and restarted with a tap on one of its joints. When running at collaborative speeds, guarding is not required. For high-speed operations, a laser safety scanner is available.
“The cobot’s dexterity and the laser safety scanner are really nice features,” says Clairain. “It gives us access to the area without the need for guarding or fencing. The laser safety scanner can be configured to have specific “keep-out zones” and if an operator enters that defined area, the robot immediately stops until the operator clears that area.”
Abello determines the parameters so that operators can safely perform tasks in proximity to the cell. Abello’s experience with the initial application has opened the door to other teach-by-touch opportunities. He has taught the cobot how much pressure it can apply when handling cosmetic parts, for example. Because the OB7 can sense pressure, Abello has plans to teach it to take over a manual buffing operation.
“This was our proof of concept,” says Clairain. “It was our first step into the robotic realm, and it has opened the eyes of management to the potential of these cobots. The advantages we’ve experienced already are substantial—the applications unlimited.”
This case study was featured in FF Journal Magazine. To read the full article, click here.