Motion Analysis Speeds Production
System enables users to identify problems in high-speed production.
Applying logos or print to pills or other small products is no easy task. It requires complex machinery capable of high-speed precision handling and positioning. As manufacturers attempt to balance the task of customizing their equipment with the search for ways to shorten cycle times, the potential for machine problems is high.
John Pitts, the operations manager at Ackley Machine Corp. (Moorestown, NJ), knows just how time-consuming and costly those problems can be. Ackley Machine designs and manufactures high-precision positioning equipment for the pharmaceutical and confectionery industries. Its machines use high-speed rotogravure offset presses to print names or logos on pills or other small products. "We're specifically interested in printing on product," Pitts says, "but our positioning systems are used for virtually anything where product must be precisely located."
Images of a high-speed positioning unit and offset press are captured by the motion analyzer.
Ackley's multilane equipment handles up to 1 million items per minute. At those rates, shafts and gears function at very high speeds. With so many small components moving so quickly, identifying the source of design or performance problems is difficult.
Typically, the only solution available to manufacturers is to test the machinery repeatedly. Pitts explains that in the past, after a customer approved the preliminary designs of a product and Ackley engineers had manufactured a small batch, they would begin testing. "We'd test the machine, and based on the results of the test, we'd modify, test again, modify, test again, and perhaps make new components," he says. "It was an extraordinarily time-consuming, costly, and tedious procedure."
Despite continuous testing, when a problem did occur, tracking down the specific cause was still an arduous task. "Our equipment runs at such high speeds," Pitts says, "we could not truly see what was happening in the process." On top of that, the constant testing created machine scheduling problems.
Pitts and his team searched for a method to identify problems in the high-speed machinery as they occurred, not after the fact. "We needed to be more scientific in our resolution of these problems," he says. Their search led them to the Motion Analysis Systems Div. of Eastman Kodak Co. (San Diego) and the EktaPro Hi-Spec motion analyzer. The portable motion analyzer enables technicians to visually break down the entire machine process and study it, step by step, identifying potential or actual problems in even the most fast-moving equipment. With the motion analyzer, Pitts says, "we saw things we didn't even suspect were going on."
The motion analyzer records images frame by frame. It can record up to 1000 full frames per second or up to 12,000 split-frame images per second. More than 19,500 images are retained in dynamic memory and stored in digital format with up to 256 gray scales. Frames are viewed in slow motion for clear, immediate analysis.
According to Pitts, one of the first things Kodak's motion analyzer recognized was that some pills were moving out of position as they traveled through the system. The movement was damaging the product. With the motion analyzer, Pitts says, "we saw the product jump. We had no idea this was happening." As a result, engineers modified component designs to capture the product and hold it, eliminating movement.
The ability to perform motion analysis led to refinements in Ackley's basic machine design, Pitts explains. "Now, we can look at a specific component of the machine in real time, analyze it for stress and wear, and optimize parts by making them from lighter materials." The benefits of the motion analyzer can be seen in the printing process as well because engineers can examine the transfer of ink to the product and determine ways to improve both print quality and speed.
"Before we purchased the motion analyzer, we'd just start throwing ideas at a machine problem," says Pitts. "We'd change something, modify something else, make one piece bigger and another piece smaller. We were solving problems with educated guesswork." With Kodak's motion analyzer, the guesswork is eliminated, and Pitts and his technicians can see the problems.