What a thousand-cycle test actually tells you

Every gripper we ship runs a thousand cycles on a test rig before it goes into a crate. It is one of the first things customers ask about, and one of the most misunderstood. A thousand cycles sounds like a lot, or like very little, depending on who is asking.

The number itself matters less than what the rig is measuring and what it is holding while it does. This is what the test covers, what it deliberately leaves out, and how to use the sheet that comes with the unit.

The part, not a test block

The rig runs your part. A machined test block is easier to grip and flatters every number, so we do not use one. If the sample is soft, oily or slightly out of tolerance, that is exactly what the test should see. A gripper that only works on a perfect part is not a gripper you can put on a line.

Where you send several samples from different batches, we rotate them through the run. The spread between batches is often the most useful thing the test reveals.

What it measures

Three figures go on the sheet that ships with the unit. They are that unit's figures, not the range from the product page:

• Grip force at the rated pressure, measured at the contact faces rather than calculated from the cylinder;
• Repeatability across the full run, taken from where the part actually lands;
• Cycle time measured jaw-closed to jaw-closed, including the settle time the controller waits for.

Each figure is logged across the whole run rather than averaged at the end, so drift shows up as a trend instead of disappearing into a mean.

Why a thousand

A thousand cycles is enough to settle the contact faces and show drift in the actuator. The first few hundred picks bed the faces in; after that, the numbers should be flat. If they are not, something is wrong with the unit, and it does not ship.

It is not a life test. Wear over ten million cycles is a rating based on the actuator and the materials, and we say so plainly on the sheet. Running ten million cycles on every unit would take weeks and tell you very little that the rating does not.

A thousand cycles on your part tells you more than a million on a test block.

What it does not measure

The rig is a controlled environment, and some things only exist on your floor. It does not know:

• your robot's acceleration and deceleration profile;
• the quality of the compressed air on your line;
• vibration from the press, the conveyor or the forklift route next door;
• how the part arrives from the process before it.

Those are checked at commissioning, on your floor, with the same sheet in hand, so any difference has something to be compared against.

What to do with the sheet

Keep it with the maintenance file, not in the crate. When a unit comes back for service, we run it on the same rig with the same part and compare. A change against its own sheet tells us far more than a comparison with a catalogue figure ever could — it points to faces, seals or the actuator before anything fails on the line.

Final thoughts

A test is only as honest as what it holds. Running the real part, logging every cycle and writing down what the rig cannot know is what turns a thousand picks into a number you can plan a line around.