Performance
Cycle Time
Cycle time is the time a robot takes to complete one full repetition of a defined operation, from start position back to start.
What it is
Cycle time is how long one complete pass of a repeated task takes, measured from a defined start point through the whole motion and back to that start. It's the clock that sets throughput: shave a fraction of a second off a move that repeats thousands of times a shift and the numbers add up fast.
The catch is what 'the cycle' means. A spec-sheet cycle time is a standardized benchmark move, a fixed stroke run under controlled conditions so two robots can be compared apples to apples. Your line's real cycle time includes the part, the fixture dwell, the I/O handshakes, and the actual path, which is why the quoted figure and the observed figure rarely line up.
How it actually works
The classic benchmark is a fixed pick-and-place stroke: the arm moves a set horizontal and vertical distance with a set payload, drops, and returns to start, and the manufacturer reports the round-trip time. It isolates raw mechanical speed by holding the geometry and load constant, so the number reflects the arm alone.
Real cycle time is the benchmark plus everything the benchmark leaves out. Acceleration and deceleration limits shape it more than top speed on short moves, since a short segment may never reach full velocity before it has to brake. Add gripper actuation, sensor waits, conveyor sync, and process dwell (a weld hold, a glue cure), and the process time often dominates the motion time. That's why two identical arms can post very different cycle times on different jobs.
How it differs
- Repeatability · Repeatability measures how tightly the robot returns to the same point over many tries; cycle time measures how fast it gets through one full operation. A robot can be extremely repeatable and slow, or fast and loose. They answer different questions: precision versus throughput.
- Takt time · Takt time is the pace demand sets on the line (available time divided by units required); cycle time is what the robot actually delivers. You size a cell so cycle time comes in under takt time, with margin. Confusing the two is how a cell that looks fast on paper still can't keep up.
Where you meet it in the field
- FANUC LR Mate 200iD · A fast small six-axis arm frequently quoted on standardized pick-and-place cycle time, useful when you want to compare raw arm speed against another candidate for a high-rate cell.
- Spot welding · On a weld line cycle time drives throughput directly, and here the weld hold and reposition dwell often eat more of the cycle than the arm's travel does.
Common questions
- Why is my cell's cycle time slower than the robot's spec sheet?
- The spec figure is a standardized benchmark stroke with a fixed distance and payload, run without any process. Your cycle adds gripper actuation, sensor waits, conveyor sync, and process dwell, and those often add more time than the motion itself. Treat the spec number as a comparison tool for your job.
- Does a faster maximum joint speed guarantee a shorter cycle time?
- Not on short moves. A segment that's only a few hundred millimeters long may never reach top speed before the robot has to decelerate to stop, so acceleration and deceleration limits govern the time. Top speed only pays off on long uninterrupted travel.
- Is cycle time the same as takt time?
- No. Takt time is the rate the customer demand requires; cycle time is what the machine actually achieves. You want cycle time comfortably below takt time so the cell can keep up with margin for jams, part changes, and downtime.