Robots usually warn you before they stop
Wear-related robot failures tend to announce themselves. A new noise from a gearbox, a low-battery warning that has sat on the pendant for weeks, a dress pack whose cover is splitting at the wrist, a cabinet fan clogged with dust. If nobody follows these up, the failure arrives in the middle of a shift.
The stories on the shop floor are familiar. The battery warning gets acknowledged for months, the power goes off over a weekend, and on Monday morning the robot starts up without knowing where its axes are. The cables at a welding robot's wrist chafe from constant rotation, intermittent faults start and nobody can find the cause. The gearbox oil has never been changed since the robot was installed. The only program backup is on the laptop of someone who left the company.
An unplanned stop costs more than the repair: a stopped line, overtime, late deliveries and, for automotive suppliers, the risk of stopping the customer's line. With planned maintenance the parts are ready in advance and the work happens during a stop you have chosen.
What a robot maintenance includes
We cover more than 30 check points, which fall into these main groups:
- Gearboxes and mechanics: gearbox oil or grease is changed at the interval and with the type the robot maker specifies. Axes are checked for backlash, abnormal noise and vibration. Mechanical stops are inspected for impact marks; a stop deformed in a collision must be replaced.
- Backup batteries: on ABB robots, the backup battery keeps the axis positions in memory while the power is off. It is not in the controller cabinet but connected to the SMB (serial measurement board) on the robot itself. If it runs flat, the robot does not know its position at power-up, and the axes have to be brought to their sync marks and the revolution counters updated. Replacing a battery at the first warning means not doing that job on a Monday morning. KUKA controller cabinets have batteries too, but they do a different job: they carry the controller through a controlled shutdown when the power fails. They are also replaced at set intervals.
- Cable harness and dress pack: the harness that runs inside the robot and the dress pack that carries power, signals and hoses to the torch or gripper. On welding robots the dress pack at the wrist turns constantly and wears fast. We look for torn covers, chafe marks and loose connections.
- Brakes: we check that the motor brakes hold the arm when power is removed or on an emergency stop.
- Controller cabinet: fans and filters are cleaned or replaced. In welding shops metal dust blocks cooling, drives run hot and heat-related faults increase. Connections, emergency stops and the safety circuit are checked too.
- Teach pendant: the cable, touch screen, enabling switch and emergency stop of the FlexPendant or smartPAD are tested.
- Software and backups: a full backup of robot programs and system is taken and the controller's event log is read. A recurring error can be the early sign of a fault that has not stopped the robot yet.
- Report: findings, replaced parts and parts recommended for replacement at the next visit, in writing, for every robot.
One limit, stated plainly: maintenance does not prevent every failure. A collision, misuse or a surge from the mains can stop a well-maintained robot. What maintenance does is catch wear before it fails and spot recurring problems in the event log.
How the interval is set
Robot makers set maintenance intervals by operating hours and calendar time. Heavy payloads, high speeds, hot or dusty environments and three-shift operation can shorten them. On the first visit we read each robot's total operating hours from the controller, look at any earlier service records and draw up a plan per robot.
Longer jobs such as gearbox oil changes are timed for planned shutdowns: public holidays, year-end or the summer break. That way oil, batteries and dress pack parts are on site before the shutdown starts.
Which robots we maintain
We maintain ABB and KUKA robots. The controller generation matters too: S4C+, IRC5 and OmniCore at ABB; KR C2, KR C4 and KR C5 at KUKA.
If a part needs replacing, the same team handles robot spare parts and board and drive repair. If you have recently bought a used robot, a full maintenance is the first job, because its history is unknown.
How it runs
- Inventory: model, controller type, serial number, operating hours and last service date of every robot.
- Plan: dates set around your shutdown windows; oil, batteries and likely parts prepared in advance.
- Maintenance: done on site.
- Report: findings, photos and recommended work.
- Follow-up: the next service date is set. With a maintenance contract, we keep track of the calendar for you.
Questions buyers ask
Can't our own team do this? Cleaning fan filters and checking the dress pack by eye can be part of your team's routine. Gearbox oil changes, updating the revolution counters after a battery change and brake tests should be done by someone who knows the maker's procedure. We recommend your maintenance team works alongside us during the visit.
How long is the robot down during maintenance? It depends on the robot size and whether the visit includes an oil change. That is why we put the long jobs into planned shutdowns and keep short checks for interim visits.
Our robot is still under warranty. Who should service it? Check the warranty terms with the robot's supplier. Some warranty agreements require maintenance by a specific company.