ROBOT TROUBLESHOOTING: RTS01

By Larry Bush

On Tuesday, I was called in early to assist the shift electrician on Robot 6. When the shift electrician and I examined the robot head on #6, the A & B grippers were both bent in the same direction about 3/4".

It would have done no good for anyone to attempt to carry out a MODPOS (Modify Position) until the mechanical repairs were made. The shift electrician told the shift supervisor who asked us to carry out the repairs because the only shift maintenance mechanic was busy with repairs on one of the cup sealing machines.

We straightened out the grippers and then did a "Tune" (minor MODPOS) on Robot 6 at Position 10 (Picking empty racks for placement on Indexer). Robot 6 was not picking up cups and dropping them. It was having a problem picking up the empty racks because the robot head had been crashed at some point in the near past.

The third shift electrician came in and took over. I was called to work on Robot 3. The third shift electrician couldn't get the robot tuned properly so he did a "warm reboot" on Robot 6. This reloaded the program and the program parameters from the last " program save".

Fifteen minutes later the third shift electrician was able to carry out a successful "Tune" on Robot 6. There were no more problems after the tune with Robot 6 that only picks up full and empty racks.

In the meantime, I changed out a solenoid valve on Robot 3 and then found a broken wire in a connection box on the robot head. The solenoid valve was controlled by the broken wire. That solenoid valve controlled two grippers on Robot 3.

Robot 3 does not pick up cups, only full trays and empty trays. I repaired the broken wire and Robot 3 ran with no problems. Changing the solenoid was probably unnecessary as the broken wire was supposed to energize the solenoid coil.

Nobody mentioned Robot 5 or Robots 1, 4,or 8 having any problems or dropping any cups Monday or Tuesday. We observed Robot 4 placing cups on the outfeed conveyor. The robot was not dropping cups, but it was moving down to the "Drop" position rather slowly in comparison to the "Drop" by Robot 8.

We are not authorized to make changes to that portion of the program. That is the Plastic Process Engineer's area as far as I know.

Later that week, the Process Engineer tuned the program on Robot 4 and decreased the amount of time the robot took while moving the product. This shortened the production time for each evolution by the four robot cell unit.

Reducing the time for that maneuver allowed the production lines to increase case production by the thousands of cases over a year's time. The time saved was in the seconds, but when counted over and over, 24 hours a day and seven days a week, the time adds up rapidly.

Larry Bush

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About the Author: Larry Bush has been an electrician for 47 years, and in maintenance management for 22 years. Download his e-Book "Emergency Diesel Electric Generators" and the "Maintenance Policy and Procedures Manual" !!