First time purchasers of robotic work cells have interesting insights and questions about their new robotic work cells. If you are new to robotic palletizing and other robotic work cell for manufacturing and warehousing, perhaps the following will give you some confidence to move forward on that project you have been considering.
Owners of a new robot cell should have two primary concerns about maintenance and ongoing support of their cell(s); equipment failure, and the need to make changes to the robot’s program or operation. Each of these areas of support is discussed below.
Common robot cell components
Robot cell components typically include;
- Safety equipment (light curtains, push buttons, pull cords, safety relays, air dump valves)
- End of arm tooling (could be air or electric/servo controlled)
- Conveyor or means to deliver raw product or parts to cell, if applicable
- Conveyor or means to take away finished product or parts from cell, if applicable
- Part registration mechanism(s)
- PLC to control equipment within cell and/or interface with equipment outside of cell
- Input/output modules and conveyor drives to send/receive signals to/from sensors and drive motors
- Vision equipment, if applicable
- Robot and its controller
If you show the above list to the typical plant maintenance person, they are likely to be familiar with all but the last two items on the list; Robot/Robot Controller and Vision Equipment.
Years ago you might have considered doing your own tune-up on a Dodge slant 6 engine; only a skilled and well trained auto mechanic should be working on today’s car engines with their high level of sensors and computer controls. Similarly, if you aren’t working with robots and their controllers and programming language on a daily basis, it is difficult to maintain the familiarity with them to be efficient working on them.
The good news is that the most likely failure in your new robot cell will not be with the robot. In fact, with 80,000 to 100,000 hour mean time between failure (MTBF) for the most recent models of FANUC robot equipment, there is little to worry about over the life of the robot as long as your integrator or you have applied it properly (proper load capacity). If you do have a robot/controller related failure, your best line of response is going to be a trusted robot service partner – ideally one who has experience with your particular robot cell(s) or at least with robot cells performing similar tasks. If you have a limited number of robots in your plant or facility you will likely find it difficult to maintain sufficient experience/training to change out robot drives, replace wiring harnesses (a common task after 7 to 10 years of use), and do other diagnostics/support on the robot and controller. A good, respected robot service provider will typically be in / out in a day and will always charge a reasonable amount for this type of service work. Look for a “Level 4 Certified Servicing Integrator” designation for FANUC robot service providers.
More likely failures will be with other equipment that is typically simpler to diagnose and troubleshoot – such as limit switch or photo cell failures, or switch/photo cell being out of adjustment, end-of-arm tool mechanism failing or being bent/broken due to mishandled part or part out of tolerance, and input or output card failure. The trickiest failure mode is typically faulty wiring due to wear and tear – repeated flexing will cause wires to fatigue and eventually break, most commonly at connection points. These failures can be intermittent and therefore difficult to diagnose and locate. Once located, they may need a special crimping tool to reassemble properly. A good technician will be methodical in locating and correcting these types of failures. A technician without the requisite skills or experience may never locate the source of the problem. Again, a servicing integrator can be your greatest ally with this type of problem.
If you have internet access on your factory floor, some robot integrators and most OEM manufacturers will have remote internet diagnostics. Keep in mind, however, that if you purchase your robot cell from an integrator you will want to contact the integrator for support rather than the robot’s manufacturer. The OEM supplier of the cell will have no documentation on any portion of the robot cell except for the robot itself. This is why it is so important to ensure that your integrator (or OEM) will be able to support you during any time your factory is in operation. If you are running a 24×7 operation, make you’re your integrator will provide a phone number for a technical contact 24 x 7.