When I worked for Alpha Glass Machinery, one of the machines it distributed was the Omega 60 by Comandulli, an Italian company. The Omega 60 was a stone edge-finishing machine. If you have seen custom granite countertops, you have seen something similar to what this machine does. One of the Omega 60s was having intermittent oscillation encoder errors.
Though the problem was intermittent, it was becoming annoying. Since the error message pointed to the oscillation encoder, we ordered a replacement oscillation encoder from Italy. I installed the replacement. The problem came back about a week later. I had worked with an ABB robot that had servo-following errors, and this seemed like a similar problem. The oscillation movement was hydraulic.
I did not have any experience with the machine, so I asked to have an Italian technician come to look at the problem. I also asked for the hydraulic components that might be part of the problem. I was guessing that a check valve was not opening or closing properly. The hydraulic system also had an unloading valve that was energized to power the oscillation movement.
While the machine ran production, I was watching the pressure gauges for a couple of hours. I happened to notice the unloading valve LED come on to indicate it was energized, but the pressure gauge still showed no pressure. That's when the machine failed on the oscillation encoder error. The error was cleared, the machine restarted, and the same thing happened a short time later. The spare parts available included an unloading valve. We replaced the unloading valve and didn't experience the error again.
This entry was submitted by Glenn Aitchison and edited by Rob Spiegel.
Glenn Aitchison's first field service job was in 1987. Since then he has worked in the robotics, automotive, and industrial automation and machinery industries. He received his Certificates of Qualification as an Industrial Electrician and as an Industrial Mechanic (Millwright).
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