What makes up a laser-cutting cycle and where time is actually lost ART-131

What a cycle means in a practical calculation

For one production batch, separate at least four time levels. This follows modern laser-processing practice, where machine, programming, automation and planning are connected parts of production rather than a single speed number (TRUMPF: Laser cutting; Lantek: Production planning).

1. Job preparation time — checking drawings, nesting, creating or checking the program and preparing material. 2. Machine cycle — sheet loading and location, piercing, cutting, rapid moves and completion of the program. 3. Post-process time — removing parts, sorting, marking, deburring and measuring. 4. Waiting time — the machine queue, missing material, operator, gas, unloading or a decision about a reject.

Use machine-cycle time to assess laser occupancy. For actual order lead time, add preparation, logistics and waiting; the indicators must not be mixed.

In simplified form:

Cycle time = cutting time + piercing time + rapid moves + loading/unloading + other machine operations.

For batch cost, separately add program preparation, inspection and time that is distributed across all parts in the nest.

What the machine cycle consists of

### Loading and locating

Even a fast laser does not cut the moment a button is pressed. A sheet must enter the work zone, rest on supports, have its position checked and pass the operations required by the control system. In manual work this depends on sheet format, mass, table access and workstation organisation. In automated work it depends on the store, gripper, route and coordination of signals between systems.

Time is often lost because the next sheet is not ready. The machine may be technically free but wait for material delivery or removal of the previous batch.

### Finding the datum and checking the sheet

The system can search for an edge, check position, control height or make other auxiliary actions. They are necessary for stability, but their time must be visible in records. Standard, consistently supplied sheets may allow optimisation of repeated actions within permitted functions. With distorted or variable material, reducing checks can increase reject risk.

### Piercing

Piercing is a separate step that creates the starting hole for entering a contour. Its duration depends on thickness and material, piercing type, gas, nozzle condition, surface requirements and number of starts. In a complex nest, dozens or hundreds of small contours may consume a major share of the cycle through piercing alone.

Piercing is not merely “extra seconds.” A failed start can create spatter, damage a nozzle, increase deburring or require a repeat pass. Optimising starts must therefore account for quality and process limits.

### Active cutting

This is time when the head follows its path with the laser on. It depends on cut length, speed on different segments, corners, radii, holes, acceleration and contour-processing technology. Catalogue maximum speed is almost never the average for an entire part: the system slows at corners, small holes and transitions.

For analysis, separate total cut length from time shown by the controller or planning system. If length is short but time is high, look not for a “slow laser” but for starting operations, geometry or movement.

### Rapid moves

Between contours the head moves without cutting. This uses machine time although no metal is processed. Long traverses, inefficient contour order, small parts placed far apart and unnecessary returns can significantly increase cycle time.

A CAM system or planning module may change processing order, but it must not optimise distance alone. Consider thermal effect, sheet stability, micro-joint rules, part access, tipping risk and quality requirements.

### Zone changes, repositioning and completion

Large sheets or non-standard parts can require repositioning, re-location, coordinate changes or other actions. Tube cutting additionally includes stock feed, rotation, long-profile support and removal of the finished part. In combined lines, calculate not only laser time but synchronisation with the other operation.

Where time is most often lost

| Loss area | How it appears | How to check | Possible response | |---|---|---|---| | File preparation | Operator corrects a drawing for a long time before launch | Measure time from file receipt to a ready program | Standardise formats, layer rules and DFM review | | Sheet loading | Machine waits for material or unloading | Compare laser-running time with department occupancy | Prepare material, change logistics, consider automation | | Many pierces | A small batch has an unexpectedly long cycle | Count starts per sheet and timing by pierce type | Review nesting and technically permitted contour merging | | Rapid traverses | Long moves between parts | Review CAM path or cycle log | Reorder without breaking quality rules | | Small holes and corners | Average speed is far below the stated value | Separate straight, curved and small-contour time | Analyse geometry, parameters and part requirements | | Post-process work | Parts take too long to sort and deburr | Measure time per sheet and batch | Improve marking, access, containers and inspection | | Waiting | Frequent pauses without a process reason | Keep a downtime log with reason codes | Material planning, maintenance, training, critical-resource reserve |

How to calculate losses on one real batch

Use not an ideal test part but an order that regularly passes through the department. Record preparation start, program readiness, sheet loading, first pierce, completion of the last contour and transfer to the next operation. Mark interruptions separately: missing material, operator intervention, equipment warnings, consumable changes and waiting for unloading.

Then divide time by category. A conditional 42-minute cycle may contain 24 minutes of active cutting, 6 minutes of piercing, 4 minutes of rapid moves, 5 minutes of loading/unloading and 3 minutes of other machine operations. This is a method example, not a norm. It demonstrates that a 10% reduction in active cutting differs from a 10% reduction in loading when their cycle shares differ.

Track three indicators:

• machine time per sheet;
• finished parts per calendar hour;
• share of scheduled time without production output.

The first supports costing, the second shows real department productivity, and the third identifies organisational loss.

How to decide what to optimise first

Start with the largest total loss that has the lowest quality risk. If material waits beside the machine, changing cutting speed will not solve it. If hundreds of pierces consume half the cycle, analyse geometry and nesting. If active cutting dominates, then compare parameters, source, head, gas and new-equipment options.

Before an investment, ask a supplier to calculate a specific test rather than maximum speed: your material, thicknesses, actual product mix, parts per sheet, loading time, pierce count and edge requirements. That is comparable with the current process.

How to turn measurements into a decision

After the first measurement, do not immediately buy a new machine or change CAM. Make a simple loss map for typical orders. For each batch record sheet and part count, total cut length, pierce count, active-cut time, traverse time, loading/unloading time and pauses with their causes. Several batches reveal recurring factors.

Separate one-time from systemic loss. A delay caused by one missing sheet should not determine investment, but regular material waiting characterises the supply process. One long repair does not prove the whole machine inefficient, while repeated stops from the same warning need a service analysis.

Calculate sheet productivity and part productivity separately. Two nests can have the same part count but different cut length, pierce count and sorting time. “Parts per sheet” without cycle time is incomplete. For a commercial order compare machine minutes, accepted-part output, gas use, post-process work and quality stability.

Once the main loss is known, state a testable hypothesis: preparing the sheet before launch reduces waiting; reducing unnecessary starts reduces piercing without harming the edge; changing contour order reduces rapid moves without increasing thermal distortion. Each hypothesis needs a baseline, one change, a control cycle and a success criterion.

Organisational losses usually need planning, material reserve, better file handoff or role allocation. Process losses may need review of parameters, tooling, gas or CAM. If manual movement of heavy sheets is the constraint, consider loading mechanisation. Mixed product range and long queues require planning and prioritisation rules.

When selecting equipment, ask suppliers to separate the stated result into components: time for the real part, loading, piercing, gas and thickness, and whether operator work is included. Agree a test task before negotiations so every supplier calculates the same scenario. Advertising maximum speed alone is not a sufficient decision basis.

For routine control, a simple weekly form is enough: five frequent batches, planned and actual cycle, principal deviation and action for the next week. Do not collect metrics nobody uses. Operator, technologist and manager must use the same names for time categories.

Keep primary measurements rather than rounding all elements to hours. In short cycles, tens of seconds can change the conclusion, especially across many sheets. Round only in the final manager/planner report so decisions rely on checked data, not impressions.

How not to confuse cutting speed with department output

Nameplate speed is useful for first comparison, but it does not answer how many accepted parts a department makes per shift. It can be stated for a particular thickness, material, short straight contour and optimum configuration. A real part has holes, corners, transitions, pierces, tabs, quality requirements and sometimes repeat passes. The nameplate figure should be understood within its limits, not dismissed.

Separate speed on an individual segment, machine-cycle time and department throughput. The first belongs to cutting. The second also includes piercing, movement and sheet handling. The third adds material supply, personnel, sorting, inspection and downtime. They can differ several-fold; a commercial assessment must state which indicator is meant.

Two nests can yield the same part count: one may have shorter traverses but more small holes, the other a longer contour but fewer starts. Choosing by cut length can wrongly favour the first although its real cycle is longer because of piercing and slowing on small features. A control test must therefore contain real geometry, not a nominal line.

Also examine cycle completion. If parts are difficult to separate, mark or transfer to bending, gains in machine seconds can disappear at the next operation. The department needs a flow of finished parts, not only head-motion time. Report indicators separately so losses at other stages are not attributed to the laser.

Comparing programs with different quality criteria is another risk. If one test permits more manual deburring while another requires a clean edge without finishing, cutting time is not a fair criterion. Include acceptance criteria, accepted-part count and post-process actions in a supplier request.

Typical mistakes

A common mistake is calling all time while an operator waits for a program to end “cutting time.” Others are comparing machines by power or maximum speed without the same part; reducing moves at the cost of collision, thermal distortion or quality; omitting unloading and sorting; building the business case on one ideal unrepresentative test; and recording downtime as “unclear” instead of using reason codes.

Cycle-analysis checklist

• [ ] A real repeatable batch was selected.
• [ ] Preparation, machine-cycle and post-process time were recorded.
• [ ] Contour and pierce count were calculated.
• [ ] Active cutting and rapid moves were measured separately.
• [ ] Every pause and cause were recorded.
• [ ] Loading and unloading time were checked.
• [ ] The same part was used for every option.
• [ ] Any process change was checked for quality and safety.

Limits of this answer

This article explains the production-cycle structure and a method for finding time losses. It does not establish guaranteed output, replace a technical test or promise a particular saving from particular equipment. Exact results depend on material, geometry, thickness, source, head, gas, CAM, loading method, staff qualification and department organisation.

Conclusion

A laser machine works not only while the beam cuts metal. Honest assessment requires the entire cycle, from file readiness to transfer onward. Once time is separated into active cutting, piercing, movement, sheet handling and waiting, it is clear where program optimisation, better organisation, new equipment or automation is needed. That provides a basis for comparing proposals and calculating real rather than advertised productivity.

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