The roll setter decides how long the line sits idle: HR for roll forming units

A roll forming line looks automatic once it runs. Coil pays off the decoiler and passes the entry guide. It bends gradually through a row of roll stands. Out of the flying shear comes trapezoidal roof sheet, C purlin or shutter slat. The run itself needs watching more than skill. The skill sits in the hours between runs, when one profile comes off and another goes on. Our coil line and profile shop page puts it at the top of its strains.

Swapping a roll set is more than unbolting and refitting. The setter loosens the outboard housings, slides the old rolls off each shaft and fits the new set in order. He packs spacers and shims so each pass sits on the strip's centreline. He sets the gap pass by pass. Then the trial strip goes through, and the real work starts. A sheet that bows, twists, flares at the cut end or shows oil canning tells him which stand to adjust. A good setter reads that sheet in one look. A weak one adjusts three stands to fix a fault that lived in one.

• Roll set fitted in the wrong order. The profile comes out close but never quite right, and nobody can say why.
• Centreline drifts between stands. Edge wave appears on one flange only, and hours go into the wrong pass.
• Punch and shear timing left from the last job. Holes land in the wrong place on purlins, and a bundle is scrapped.
• First-sheet check rushed. A length or profile fault is found at a building site rather than at the run-out table.

Most units grew around a single gifted setter. He learned on the line, often from the machine builder's commissioning engineer, and kept his own notes. Shim stacks, gap readings and the stand that always needs a touch more for one customer's profile live in a pocket notebook. Nobody asked him to share it, and sharing gains him nothing. His standing, and often his overtime, rest on that scarcity. Owners know the risk but feel stuck. Training a second setter takes line time, and the order book rarely leaves any.

Pay often makes it worse. A setter paid like a line operator, plus whatever overtime the changeovers create, earns more when changeovers run long. Nobody intends that, yet the signal is plain. Then a purlin fabricator nearby tempts him with a fixed day shift and slightly better money. Only then does the owner learn what that notebook was worth.

Set a short ladder. Line operator. Assistant setter, who can fit a roll set under watch. Setter, who can change over named profiles alone and pass the first sheet. Senior setter, who can change over any profile in the shop, sort out a new roll set from the toolmaker and teach. Attach a pay step to every rung, tested against nearby rates via pay benchmarking for roll forming units. Pay the rung. Overtime ought to be occasional, never the main reason setting pays.

Date, line, shift, setter, assistant.
Profile coming off, profile going on, roll set number.
Coil: thickness, width, coating, supplier lot.
Stands adjusted after first trial, and what was changed.
Shims or spacers added or removed, by stand.
Faults seen on trial strip: bow, twist, flare, edge wave, oil canning.
First good sheet: length, profile gauge check, inspector's initials.
Minutes from last good sheet of old profile to first good sheet of new.
Setter's tip for whoever fits this roll set next.

Use the sheet to learn, never to punish. Over a few months it shows which profiles are slow for everyone and which are slow only for certain people. It also turns the notebook into shared knowledge without asking anyone to hand it over in one go.

1. 1

   Let the senior setter pick his apprentice

   He knows who on the line notices a flared end before the shear. Someone he chose, he will teach.

2. 2

   Join every changeover for a fixed period

   The assistant fits, the setter checks. Then the roles swap on the easiest profiles.

3. 3

   Turn the notebook into profile cards

   One card per roll set: stand order, shim stacks, known trouble spots, first-sheet checks. The setter writes, the assistant copies, both sign.

4. 4

   Sign off profile by profile

   Roofing sheet first, then simpler purlins, then shutter slats or door frames. Record each sign-off against the role card in your role design for roll forming units.

5. 5

   Reward the teacher

   Once a senior setter has signed off an apprentice, he climbs a rung or draws an instructor's allowance. Passing on the craft then raises his status instead of eroding it.

A setter waiting for a coil to be loaded is still idle time. Crane slings, coil cars and sharp sheet edges sit with helpers who are often the least trained people on site. Train them on slings and coil cars first, and fold coil loading into the changeover plan so the next coil is staged while rolls are being swapped. The roll forming safety page covers crane signals and edge handling.

If your senior setter were away for a fortnight, which profiles could you still run? Write the answer down line by line. Those lines on paper mark your exposure. Changeover sheets plus an apprentice setter shrink it. Roll forming sits beside hammer and press shops in our forging and forming hub.