Retrofitting a robot into a line that cannot stop

Most of the robots we install go into lines that are already making parts. There is no greenfield hall, no month of commissioning and no spare shift to learn on. There is a maintenance window, a production manager who needs the line back on Monday, and a station that has been run by hand for longer than anyone on site can remember.

That changes how the whole job is planned. A new line is designed forwards, from the first drawing to the first part. A retrofit is planned backwards, from the hour the line has to run again. This is how we do it, and why the order matters more than any single piece of hardware.

Start from the restart

A retrofit has one fixed point: the hour the line has to make parts again. Everything else is planned backwards from it — the order the old setup comes out, the order the new one goes in, and the point after which going back is no longer an option. We call that the point of no return, and it goes on the plan before anything is ordered.

If the work cannot fit the window with room to spare, we say so then, not on the night. Sometimes the answer is to split the job across two shutdowns; sometimes it is to prepare more on our bench so less happens on site. Either is better than a line that is still down when the morning shift arrives.

Map the interface before building anything

Most retrofit trouble is not mechanical. It is a signal named one thing in the PLC and another on the drawing, or a safety circuit that was extended years ago and never documented. So the first visit is spent reading the line as it actually runs, not as the drawings say it should.

During that visit we record:

• every signal the new station has to read or write, with its real address;
• the stop categories on each safety circuit it will join;
• air, power and network supplies within reach of the station;
• the space the station has to fit, measured on the floor rather than taken from a layout;
• how the engineers on site name things, so our tags match theirs.

That record becomes the map the arm and its tooling are wired against on our bench.

Prove it on the bench, not on the floor

Once the station is wired, it runs your part through the real cycle on our bench. Not a demonstration cycle and not a test block — your part, at your rate, for a full shift. That is where approach paths get tuned, grip force gets set and the odd jam gets designed out.

By the time the crate leaves, the station has already done the job it is going to do. Commissioning on site becomes a check that nothing changed in transit, not the first time the cycle has been attempted.

A station that first runs on the night of the shutdown is a station that gets finished the morning after.

The plan, in order

Every retrofit we run follows the same sequence. The dates change; the order does not.

1. Survey the line — signals, addresses, services and the space the station has to fit.
2. Build and wire on our bench against that survey, not against a generic layout.
3. Run the real cycle with your part until the numbers hold across a full shift.
4. Mark the point of no return on the shutdown plan and agree it with your maintenance lead.
5. Install, commission and hand over — drawings, addresses and the spares list on the day.

Skipping a step rarely saves time. It moves the work to the one place where time is shortest.

Keep the old setup in a box

The equipment that comes out is not scrapped. It is boxed and kept beside the line until the new station has run a full week at rate. Nobody has needed the box yet. It still goes beside the line, every time.

It costs a corner of floor space for a week. In exchange, the people who sign off the shutdown can do it knowing there is a way back — and a plan with a way back is much easier to approve.

Final thoughts

Retrofits have a reputation for overrunning, and most of that reputation is earned by work that started on site instead of before it. Survey first, build and prove on the bench, and plan the shutdown backwards from the restart. Done in that order, most lines run again the next morning, with a station that already knows the part it is holding.