1. Robot Construction
Repairing the Robot

2. Preventative Maintenance (PM)
When it comes to repairs, proper preventative maintenance can equate to a savings in both cost of parts and time involved.
Preventative maintenance is the practice of changing out parts and doing repairs in a scheduled fashion (based on previous equipment and component performance) before the equipment breaks down or quits working.

3. The literature for many robots includes a schedule of PM, such as
Since preventative maintenance is done before a machine breaks down, it can be scheduled at a convenient time.
The literature for many robots includes a schedule of PM, such as
checking the level of a hydraulic tank is a daily task
tightening all the electrical connections would be a yearly task
greasing the bearings and tasks of this nature are usually required every three or six months
replacement of the wiring tends to fall in the three- to five- year category

4. PMs are scheduled based on the previous performance of equipment.
Someone keeps careful records of part failures to determine when PM should be done.

5. The systems of the robot determine the types of preventative maintenance required.
Electrical systems need connections tightened yearly, electrical motors replaced, clean or replace encoders, check cooling fans for functionality and dirt buildup, pull the electrical cards from the controller and put them back in or reseat them to insure proper connection, voltage and amperage checks, verification of electrical safety systems and other sensors, replace batteries.
Reseat is the process of removing electronic cards from the controller and putting them back in to insure proper connection.

6. Hydraulic systems need periodic monitoring of the fluid for contaminants such as dirt, water, and metal fragments as well as replacement of the oil; periodic testing of the oil for the proper consistency and chemical make-up; cursory checks for leaks; change system filter; check the gas charge for accumulators; valve removal and cleaning; and check hoses for leaks and signs of wear
Accumulators are devices used to store hydraulic pressure and then release it back into the system as needed.

7. Pneumatic systems need checks for leaks, damage to hoses/piping, changing of filters, add oil to lubricators, check mufflers for damage or clogs, and cleaning and draining reservoir tank.
Mechanical systems need greasing and lubrication, checking gears, check belt and chain drives.

8. Four arguments in favor of doing preventative maintenance are:
Preventative maintenance can be scheduled.
Preventative maintenance saves money.
Warranty voided if preventative maintenance is not done.
Shipping and handling rates.

9. Precautions to Take Before You Begin Repairs
Before beginning repairs, make sure the area is safe for you to work.
Lockout/tagout (LOTO) is the process of removing and draining all power sources from a piece of equipment to reach a zero energy state and then ensuring that they cannot be reactivated by the use of lockout devices and personalized locks.

10. Zero energy state is when a machine has no active or latent power.
To get to zero energy state turn off all electrical, hydraulic, and pneumatic power coming to the machine and bleed off any residual pressure, discharge any capacitors, and either lower portions of the equipment that could fall or block them in place

11. As part of the LOTO process, lockouts are used.
Lockouts are devices used to hold the power source in the blocked or de-energized state.
No matter how you turn the power source off, there is a lockout designed to keep it turned off, and each lockout has a place for a lock or hasp that can hold multiple locks.

12. The following checklist is a step-by-step procedure for the lockout process:
Notify affected individuals that you are about to shut the machine down. This includes operators, nearby employees, and management.
Stop the machine cycle, if necessary.
Turn off or remove all external power supplies and lock them in the off position using lockout devices and a lock with your name on it.
Place appropriate information tags on the equipment, such as “Do Not Run-Under Maintenance.”

13. 5. Verify a zero energy state
5. Verify a zero energy state. Make sure to account for capacitors, compressed springs, items that could fall, stored fluid pressures, or other potential energy sources. 6. Perform repairs. 7. Once finished, remove all tools and any blocking devices or other items that you added to the machine for safety reasons. 8. Once everything is clear, each person working on the robot removes his or her own lock; the last person can return power to the equipment

14. Make sure that you have all parts on hand before beginning a repair.
The delay could turn into a chance for other technicians to rob parts from the machine to repair other machines, nuts and bolts seem to wander off, and when the part finally comes in, someone else may finish the repair all of this adding to time and frustration for the repair. 

15. The following are tips to help repairs or preventative maintenance go smoothly once you are ready to start:
Take pictures before removing a part or unwiring a system.
Keep all the parts together to make the assembly process easier.
Get help before you need it.
Take good notes that can be used down the road – keep a technician’s journal.

16. One of the major problems with part swapping is that part swapping only addresses the symptoms and not the cause.
if you do not track down the root cause of the problem you should make sure to perform all reasonable checks for functionality and record your results and if possible, compare these to another robot of the same type and see if the system if running normally.

17. Precautions Before Running the Robot
The checklist of tasks once you have finished repairs is:
Check the system for tools, spare parts, and foreign objects before putting on the covers.
Make sure that everyone is clear and all the covers are in place.
Check for any alarms or unusual action by the system
Load in the proper program and start the robot back into normal operation

18. Once you have powered up the system after a repair, some simple tests that you can perform to check operation include:
Check for any alarms or unusual action by the system
Place it in manual mode and check each axis to ensure proper operation
Try running a simple program, such as a homing program or alignment check program.
Verify all the safety equipment and sensors are working.

19. What To Do If The Robot Is Still Broken
These are four questions to ask if the system is not fixed after repairs:
Is it better than it was?
Is it worse than it was?
Was there no discernible change?
Is there a new problem?

20. If the problem is misdiagnosed, it can create new problems during the repairs.
The best fix is to undo what you did and see how the system responds; if you return to your original problem, then you know that whatever you did was unrelated.
If your original problem does not return, then you have a worst-case scenario.

21. If there is no discernible change, then it’s possible that whatever you worked on is not likely part of the problem. This often happens.
Another possibility if there is no discernible change is that the new or rebuilt part you put in the robot is bad. This doesn’t happen often.

22. Sometimes new problems emerge after repairs.
The system had multiple failures and you have fixed some, uncovering other problems.
You damaged something on the robot while repairing it.
You misdiagnosed the robot and created a completely new set of problems while fixing it.

23. Three things to remember once you fix the system and confirm proper operation:
Put everything back in its place.
Finish the paperwork.
Deal with the parts used.