Approach, Working and Return Speeds: What Creates a Real Bending Cycle ART-216

The short answer

The fastest quoted axis or ram value is not a production promise. A reliable comparison records the complete route from taking a prepared blank to placing the accepted part in agreed storage. Separate repeatable steady-cycle work from planned setup and from losses. This makes clear whether a delay belongs to machine motion, part handling, program preparation or workplace organisation.

What the speeds in a datasheet actually mean

Approach speed is the ram movement toward the working area; working speed is the controlled forming phase; return speed is movement away after the bend. Their usable values depend on opening height, program, safeguards, material, thickness, tooling, angle and technology. They cannot be read as independent output figures.

Model of the complete cycle

For a repeatable part, map pickup, feed, locating, each bend, backgauge positioning, turns or flips, support, inspection and placing. Add planned work separately: tool change, first-part verification and preparation of the next batch. Record losses such as waiting for material or a crane without presenting them as proof that a faster drive is needed.

Table for comparing cycles

| Stage | What it shows | Other influences | How to compare | | --- | --- | --- | --- | | Approach speed | Ram time to work area | Opening height, program, safeguards | Same program and stroke height | | Working stroke | Bend-forming time | Material, thickness, tooling and angle | Tie it to the actual operation | | Return speed | Ram withdrawal time | Next gauge position and pause | Record with axis positioning | | Backgauge | Time to prepare the next coordinate | Axes, geometry and re-approaches | Note waits and corrections | | Feed and locating | Time to place the part correctly | Size, mass, flanges and visibility | Measure a typical part, not an empty cycle | | Turn or flip | Orientation-change time | Length, sag, support and second worker | Include every recurring movement | | Tool change | Transition between real batches | Tool plan, storage and automation | Separate it from steady tact | | Inspection and first part | Time to confirm output | Control frequency and route | Record planned control and rework separately |

There is deliberately no universal “seconds norm” in this table. It identifies what must be measured and discussed in a technical proposal.

How to create a measurement map

First define the boundary: for example, from an operator taking a prepared blank to placing the finished part in agreed storage. Use that same boundary for every comparison. Select a small set of real positions: a simple serial part, a typical medium-complexity part and a part that repeatedly creates delay. Record material, thickness, bend count and sequence, tooling, locating, turns, support and control frequency.

Group time into steady cycle, planned time, losses and external operations. The grouping does not ignore losses; it prevents solving an organisational issue by buying a faster machine.

Why the same number of bends can produce different tact

Two parts may each have four bends and still require different time. A small blank with easy gauge access moves quickly. A long panel may require support, careful rotation and inspection so an earlier flange does not interfere. For a housing, the operator may change the locating side; for many small parts, sorting and stacking can take more time than ram motion. Record the action after every bend, not only the bend number.

Role of the backgauge, program and pauses

The backgauge affects rhythm as well as position accuracy. A simple part can move to the next coordinate almost invisibly; a complex route can require extra motion, re-locating or correction. Record actual positions, waits and manual changes instead of only the quoted number of axes.

Controllers and offline software can help with programming, sequence calculation, simulation and tooling verification, but the result must be confirmed for the actual machine, tooling, software version and data. Do not change movement limits, safeguards or service settings merely to shorten a measurement.

Changeover and mixed production

Steady tact can dominate a large batch, while transition time often matters more in frequent small batches. Transition includes approved program preparation, finding and installing tooling, first-part verification, clearing prior tooling and material organisation. Compare at least a stable series and a real mixed day, or its agreed model. Ask a supplier to separate machine cycle, automatic tooling change and operator work.

How to compare two presses correctly

1. Provide the same drawings, materials, quantities and process assumptions. 2. Choose parts that really form the production flow, not only the easiest one. 3. Request the full route: feed, locate, all bends, turns, control and stacking. 4. Agree whether tool change, first-part preparation and a second worker are included. 5. Record machine, controller, tooling, program and measurement method. 6. Separate stated capability, expectation for your part and a result proven only by a test.

The useful comparison is not “the fastest press” but the best result on an agreed part set.

Common mistakes

• Treating approach or return speed as part tact.
• Comparing an empty machine cycle with complete operator work.
• Measuring a demonstration part and extending the result to all products.
• Omitting turns, support, stacking and backgauge waits.
• Mixing steady cycle, changeover and losses into one average.
• Failing to record tooling, program, material and test conditions.
• Changing safety or service parameters without manufacturer documentation.

Checklist before a productivity assessment

• [ ] Cycle boundaries are identical for all measurements.
• [ ] Typical serial and mixed positions are selected.
• [ ] Material, thickness, bends, tooling and program are recorded.
• [ ] Approach, work, return and gauge movements are separately noted.
• [ ] Feeding, locating, turns, support and stacking are included.
• [ ] Changeover, first-part control and losses are not hidden in one number.
• [ ] Demonstration conditions match future work or are clearly different.
• [ ] The conclusion is called an estimate unless a test has confirmed it.

What cannot be determined without data

Without drawings, material, thickness, bend count and sequence, tooling, batch pattern, feeding method and workplace organisation, no honest cycle time or shift output can be stated. A datasheet speed from one configuration cannot be transferred to another. Video is not complete evidence unless the full route and measurement conditions are visible.

Select a configuration for your part