- Operating feel combines operating force, drift after stopping, rebound, response delay, end-effector inertia and ergonomics. Recording these measures alongside operator feedback supports comparisons of equipment condition and assessment of improvements.
- Relate operator feedback to measurable causes: heaviness to operating force, jerky starts to breakaway force and resistance variation, upward/downward drift to balancing-pressure error, rebound to air compressibility and end-effector inertia, and uneven load switching to pressure transitions and response delay.
- Balancing-pressure adjustment is a key check: in the worked example, a 0.02 MPa pressure error produces approximately 37 N of additional operating force. Record pressure alongside operator feedback.
- Cross-check results using a push-pull force gauge + pressure/displacement/angle sensors + response acquisition + subjective ratings. Combine A–D grading, FMEA and an operating-feel test record to make evaluations traceable.
Produced by: Jiangsu AUREK Intelligent Technology Co., Ltd. (AUREK Engineering Research Group) · Document type: engineering research and methods · Version: V1.0 / 2026. Formulas, worked examples and example data illustrate analysis and evaluation methods; project parameters are determined from prototype measurements, customer operating conditions and safety requirements. The full PDF is available for download.
00Abstract
During handling, assembly, loading and unloading, operators directly push, pull, position and release workpieces. To evaluate effort, smoothness and stability, record operating force, starting force, constant-speed force, drift after stopping, rebound, response delay, joint damping, end-effector inertia, tooling weight, air-supply pressure stability, unloaded/loaded pressure-switching logic and ergonomic factors. Together these describe operating feel and provide a basis for comparing operating conditions.
This method draws on AUREK pneumatic industrial manipulator prototype ARK-S01 and site commissioning experience to support design, commissioning and acceptance evaluation. Digital push-pull force gauges, pressure, displacement and angle sensors, response-time acquisition and subjective ratings compare loads, working radii and tooling states. Mechanical models explain the causes, while test records and FMEA organize diagnosis and retesting. The parameters, calculations and example data illustrate the method and must be adjusted for prototype measurements, customer operating conditions and safety requirements. A single test does not establish performance over the equipment's service life.
01Introduction
Pneumatic industrial manipulators are used for automotive parts, machining, box and plate handling, hot workpiece transfer, assembly, loading and unloading. Their assistance can be summarized as compensating for gravity while retaining operator control: the equipment compensates for weight while the operator pushes, pulls, positions and releases the workpiece. Evaluation must therefore address how operation affects efficiency, positioning accuracy, fatigue and site safety, as well as rated capacity.
Organize site feedback by motion stage: high pushing effort, jerky starts, upward or downward movement after letting go, rebound after stopping, and uneven unloaded/loaded switching. Relate these observations to measurable quantities to select appropriate tests and diagnostic methods:
| Operator feedback | Physical quantities / engineering causes |
|---|---|
| Heavy or difficult to push | Excessive operating force or insufficient balancing pressure |
| Jerky start | Starting force is too high or running resistance fluctuates |
| Upward or downward drift | Pneumatic balance pressure deviation |
| Rebound after stopping | Air compressibility and end-effector inertia |
| Uneven load switching | Uneven pressure transition or response delay |
Table 1 Operator feedback and associated physical quantities
First convert subjective feedback into quantifiable, repeatable measures, then analyze the effects of mechanical, pneumatic, control and ergonomic factors. Compare prototypes, tooling and loads under consistent test conditions. The results can inform cylinder selection, circuit adjustment, tooling weight reduction, joint damping and handle design.
02Equipment scope and definition of operating feel
This study covers a rigid-arm pneumatic industrial manipulator and its end tooling. Cylinder torque approximately balances load torque, allowing the operator to lift, translate, position and release the workpiece with relatively low effort. The system includes the arm structure, main/intermediate/front joints, pneumatic balancing circuit, control valves, operating handle and end tooling. Fully automatic control is outside this study.
2.1 Engineering definition of operating feel
Under specified load, radius, stroke, supply pressure and tooling conditions, operating feel describes the combined operating force, response stability, motion continuity, position holding and operator comfort during starting, lifting, translation, stopping, positioning, gripping and release. Evaluate the complete motion sequence under stated conditions, using measurable mechanical and ergonomic indicators.
2.2 Components of operating feel
Record mechanical, stability, response, dynamic and ergonomic measures separately, then cross-check them against operator ratings. This identifies equipment condition and distinguishes reduced effort, motion continuity and positioning comfort. The table below explains each measure's engineering significance.
| Category | Measures | Engineering significance |
|---|---|---|
| Mechanical | Starting force, constant-speed force and peak operating force | Assess operating effort and detect jamming |
| Stability | Drift after stopping, rebound and pressure fluctuation | Assess positioning and holding stability |
| Response | Button response delay, pressure build-up time, action lag | Assess pneumatic and control response |
| Dynamics | End-effector inertia, joint damping and overshoot | Assess excessive freedom of movement or heavy handling |
| Ergonomics | Handle height, grip angle, button position and two-hand posture | Assess fatigue during sustained operation |
| Subjective ratings | Effort, smoothness, stability and fatigue ratings | Cross-check against objective measurements |
Table 2 Operating-feel measures and their engineering significance
03Factors affecting operating feel
The main influences are pneumatic balancing, mechanical structure, tooling weight and end-effector inertia, pneumatic control and unloaded/loaded switching, and ergonomics. Diagnose these factors against specific motions so that adjusting one parameter does not leave other causes unexamined.
3.1 Pneumatic balancing
Pneumatic assistance approximately balances cylinder and load torque. Low balancing pressure requires extra upward effort; excessive pressure produces upward drift. Check unloaded and loaded pressure settings, supply stability, regulator sensitivity, cylinder friction and seal resistance, and the buffering effect of the air receiver and check valve. Uneven pressure transitions during unloaded/loaded switching can cause sudden upward or downward movement, making switching behavior a priority for testing.
3.2 Mechanical structure
Check the mechanical structure during starting, motion and stopping. Joint resistance, bearing and pin-bushing friction, roller condition and brake drag affect starting and constant-speed operating forces. Arm stiffness, connection clearances, arm length and moments at different radii affect force levels and consistency across positions. Difficult starts or jerky motion call for particular attention to joint lubrication, bearing contamination and brake clearance.
3.3 Tooling weight and end-effector inertia
Tooling weight, center-of-gravity offset and inertia affect handling even when the arm itself is well balanced. Assess the combined tooling/workpiece mass and rotational inertia alongside grip retention. Vacuum cups, mechanical jaws and expanding shafts create different load distributions. Turning tooling requires center-of-gravity checks at 0°, 45°, 90° and other relevant angles. Air hoses, vacuum hoses and cables also add drag during translation and return.
3.4 Pneumatic control and load-pressure switching
Evaluate pneumatic control from button actuation to cylinder movement. Check valve flow capacity against the load, throttle settings, hose length and bends, and the effects of moisture, oil and contaminants on valve response. Unloaded/loaded pressure switching is a key check: excessive pressure differences or unsuitable logic during loading and unloading can cause sudden upward motion, sinking or impact. Pressure-transition and verification logic should be considered and included in response and stability tests.
3.5 Ergonomic factors
Perform ergonomic checks alongside force measurements. Assess handle height relative to a comfortable elbow position, button reach during a natural grip, protection against unintended actuation, two-hand safety logic, obstructed visibility, and repetitive wrist and shoulder loading. Record operator height, reach and experience to help explain differences in ratings.
04Quantitative evaluation measures
Record operating force, starting force, constant-speed force, drift after stopping, rebound, response delay and pressure fluctuation separately, with subjective ratings linked to the corresponding conditions. The table below lists symbols, units and recommended instruments for consistent acquisition and comparison.
| Measure | Symbol | Unit | Recommended instruments | Description |
|---|---|---|---|---|
| Starting force | Fstart | N | Push-pull force gauge | Maximum operating force at start-up moment |
| Constant-speed force | Fcv | N | Push-pull force gauge | Average operating force during constant-speed motion |
| Peak operating force | Fpeak | N | Push-pull force gauge | Maximum force during action cycle |
| Drift after stopping | Dstop | mm | Displacement sensor / laser rangefinder | Displacement within specified time after letting go |
| Rebound displacement | R | mm | Displacement sensor / video analysis | Maximum reverse displacement after stopping |
| Response delay | td | ms | Data-acquisition system | Time from button actuation to motion response |
| Pressure fluctuation | ΔP | MPa | Pressure transducer | Pressure changes during movement or switching |
| Equivalent inertia | Jeq | kg·m² | Calculation / test-based identification | Describes the dynamic load at the end effector |
| Joint damping | Bj | N·m·s/rad | Angle sensor + force test | Reflects the smoothness of horizontal rotation |
| Subjective rating | Q | points | Rating form | Recommended 1–5 or 1–10 scale |
Table 3 Quantitative operating-feel measures
4.1 Operating force and starting force
Operating force is the push-pull force applied at the handle. Record its time history with a digital force gauge and extract starting force, constant-speed force and peak force. Lower force and variation generally reduce effort, but the system must retain enough resistance for controlled positioning. Starting force includes static friction, brake drag, cylinder breakaway friction and load imbalance:
Here, Fstart is the starting force (N); F(t) is the operating-force time history; t0 is the moment when the operator starts to apply force; tv is the time when end-effector speed reaches the specified threshold. High starting force produces a difficult or jerky start. Constant-speed force is the mean absolute operating force during steady motion; its coefficient of variation describes smoothness:
Here, Fcv is the constant-speed operating force (N); σF is the standard deviation of operating force during steady motion; CVF is the force coefficient of variation (dimensionless). Fcv reduces sustained operating effort as it decreases; CVF increases with jerky motion, stick-slip or resistance variation.
4.2 Drift after stopping and rebound
Stop drift measures the position change of the workpiece within a specified time after the operator lets go, reflecting the balance pressure, air tightness, braking state and load center of gravity stability; rebound amount measures the maximum reverse displacement that occurs in a short period of time after stopping:
Here, Dstop is the drift after stopping (mm), T is the observation time (can be 3 s, 5 s or 10 s and is fixed in the plan); R is the maximum rebound displacement (mm). Excessive stop drift will affect the safety of positioning, assembly and placement; rebound is often related to gas compressibility, throttling settings, arm elasticity, fixture inertia and the operator's abrupt stopping action. If it is too large, the workpiece may hit the positioning surface or affect assembly accuracy. Use the same observation period and record drift and rebound together when comparing prototypes.
4.3 Correlation between response delay, pressure fluctuation and subjective ratings
Response delay is the time from button actuation to motion response: td = tresponse − tbutton (ms). Measure lifting, lowering, gripping, release, unloaded-to-loaded and loaded-to-unloaded transitions separately, recording pressure fluctuation ΔP at the same time. Rate ease of starting, motion smoothness, stopping stability, response, positioning comfort and fatigue on a 1–5 scale, with 5 as the best score. Use subjective ratings to cross-check objective measurements against operator experience. Consistent relationships support the evaluation method.
05Mechanical models and calculation methods
The following simplified mechanical models explain mechanisms and orders of magnitude. For engineering decisions, correct efficiency, friction and inertia parameters using prototype measurements. These models do not directly replace detailed sizing calculations.
5.1 Cylinder output force and torque balance
The theoretical effective output force of the cylinder can be expressed as Fc = P·A·η, indicating that the output force is proportional to pressure, pressure area and overall efficiency. Taking the main rotation fulcrum as a reference, a simplified moment balance relationship can be established:
Here, Lc is the cylinder moment arm (m); W is the total weight of the workpiece and fixture W=mg (N); Lw is the horizontal distance from the center of gravity of the load to the pivot (m); Mf is joint friction torque (N·m); Mi is the additional inertial torque (N·m). The relationship shows that greater load, radius, tooling center-of-gravity offset or joint friction increases the required balancing pressure or operating force. These effects explain heavier handling with large radii and heavy tooling.
5.2 Operating force and pressure error
The force felt by the operator at the handle can be approximately obtained by dividing the combined value of the unbalanced moment, friction moment and inertia moment of the system by the equivalent moment arm of the handle: Fop = ΔM / Lh. If the air pressure deviation causes a moment imbalance, the additional operating force caused by the pressure deviation is:
Here, ΔP is the pressure adjustment deviation (Pa); Lh is the effective handle moment arm (m). A larger pressure error or shorter handle moment arm increases the force the operator must supply, so even a small pressure error can produce noticeable upward drift or heaviness.
5.3 Equivalent inertia and combined score
Approximate the dynamic load using equivalent rotational inertia: Jeq = Jarm + Σ mi·ri². Greater tooling mass, center-of-gravity offset and arm length increase inertia, starting and stopping effort, overshoot and rebound. Reducing tooling weight and bringing its center of gravity inward can improve dynamic handling. Combine the individual measures into an overall score for comparing configurations:
Here, SF, SD, SR, ST, SJ, SE are scores for operating force, drift, rebound, response delay, joint smoothness and ergonomics, respectively. Choose weights wi to prioritize safety over comfort. Give greater weight to drift and rebound for heavy loads, positioning stability for precision assembly, and operating force and fatigue for frequent handling.
06Test plan and procedure
Use a repeatable, documented and comparable test process for prototype commissioning, tooling comparisons, factory-acceptance assessment, site retests and fault diagnosis. Recommended instruments are a digital push-pull force gauge with data output, 0–1.0 MPa pressure transducer, displacement sensor or laser rangefinder, angle encoder and data-acquisition module sampling at least 50 Hz, or 100 Hz for response tests. Add video and operator rating forms. A stopwatch supports preliminary checks; synchronized acquisition aligns force, pressure, displacement and time for detailed evaluation.
Tests should cover unloaded operation, different load ratios and working radii, and transitions between loaded and unloaded states. The table below gives the recommended minimum coverage.
| Condition ID | Load condition | Working Radius | Height | Tooling condition | Description |
|---|---|---|---|---|---|
| A1 | Unloaded | Minimum radius | Mid-height | Unloaded tooling | Measure basic resistance |
| A2 | Unloaded | Maximum radius | Mid-height | Unloaded tooling | Measure the effect of reach |
| B1 | 25% of rated load | Intermediate radius | Mid-height | Normal gripping | Light-load handling |
| B2 | 50% of rated load | Intermediate radius | Mid-height | Normal gripping | Typical operating condition |
| B3 | 75% of rated load | Maximum radius | Mid-height | Normal gripping | Heavier-load condition |
| B4 | Close to rated load | Maximum radius | High/low position | Normal gripping | Near-limit reference condition |
| C1 | Loaded-to-unloaded transition | Intermediate radius | Placement position | Release | Measure switching impact |
| C2 | Unloaded-to-loaded transition | Pickup location | Pickup height | Gripping action | Test loading response |
Table 4 Operating-feel test conditions
07Worked example
The following worked example illustrates use of the models. It explains the method and is not a basis for selecting a particular product; engineering parameters must come from prototype measurements and design drawings.
7.1 Example inputs and balancing pressure
Assume the following handling condition: workpiece mass m1=80 kg, tooling mass m2=18 kg, total mass m=98 kg; load center-of-gravity distance from the main pivot Lw=1.8 m; effective cylinder moment arm Lc=0.28 m; cylinder bore D=125 mm; overall cylinder efficiency η=0.85; equivalent joint friction torque Mf=45 N·m. The calculation is:
Under the assumed conditions, load-balancing pressure is approximately 0.61 MPa, within the common industrial compressed-air operating range. If measured operating force is substantially higher at the same load, check tooling center of gravity, joint friction, cylinder efficiency, pressure fluctuations, unloaded/loaded pressure settings and handle moment arm. Comparing individual measurements with the model can locate sources of additional operating force.
7.2 Effect of pressure error on operating feel
To illustrate the importance of pressure adjustment accuracy, assume the pressure adjustment deviation ΔP=0.02 MPa, the cylinder parameters are the same as above, and take the effective handle moment arm Lh=1.6 m, then the cylinder torque deviation and additional operating force caused by the pressure deviation are:
Under the worked-example conditions, a pressure deviation of 0.02 MPa corresponds to approximately 37 N of additional push-pull force, which may be felt as upward drift or heaviness. Pressure data must therefore be recorded alongside operator feedback.
08Example records and evaluation
This section uses an example test of engineering prototype ARK-S01 to explain recording and evaluation. The table contains representative values after 10 repetitions per condition and constitutes example data illustrating the method. Prototype condition, tooling, air supply and operator differences affect results; site evaluations require separate measurements.
8.1 Operating-force test
| Load/kg | Radius/mm | Air pressure/MPa | Starting force/N | Constant-speed force / N | Peak force/N | Force coefficient of variation |
|---|---|---|---|---|---|---|
| 0 | 1800 | 0.50 | 21.8 | 11.5 | 27.4 | 0.08 |
| 40 | 1800 | 0.56 | 30.6 | 17.9 | 37.2 | 0.10 |
| 80 | 1800 | 0.61 | 38.4 | 22.6 | 46.1 | 0.12 |
| 80 | 2500 | 0.63 | 47.2 | 28.9 | 57.8 | 0.15 |
Table 5 Example operating-force data: ARK-S01, tooling G01, operator OP-03; means of 10 repetitions
In the example, starting and constant-speed forces increase with load and radius, consistent with the torque-balance model. At 2500 mm radius, the force coefficient of variation rises from 0.12 to 0.15, illustrating reduced motion smoothness at greater reach.
8.2 Drift, rebound and response delay
| Load/kg | Radius/mm | Height/mm | 5 s drift / mm | Maximum rebound/mm | Initial rating |
|---|---|---|---|---|---|
| 0 | 1800 | 1000 | 1.4 | 2.1 | Grade A |
| 80 | 1800 | 1000 | 3.3 | 5.2 | Grade A–B |
| 80 | 2500 | 1500 | 6.9 | 9.4 | Grade B |
Table 6 Example drift and rebound data: 5 s observation, prototype ARK-S01
The example shows increased drift and rebound with load and radius, particularly at large radius and elevated positions. Assess cushioning, speed limits and throttling, then retest. The example response delays of approximately 119–224 ms are recorded as acceptable in the illustrative evaluation. Unloaded/loaded switching has the longest delay and slight impact, supporting evaluation of pressure-transition logic.
8.3 Correlation between subjective ratings and objective data
| Rating item | Reference condition (80 kg, 1800 mm) | Large-radius condition (80 kg, 2500 mm) |
|---|---|---|
| Ease of starting | 4.3 | 3.4 |
| Smoothness of movement | 4.2 | 3.5 |
| Stopping stability | 4.4 | 3.3 |
| Response quality | 4.1 | 3.6 |
| Positioning comfort | 4.2 | 3.2 |
| Operating fatigue | 4.0 | 3.1 |
Table 7 Example subjective ratings: 5-point scale, operator OP-03
The large-radius example has lower subjective ratings alongside higher operating force, drift and rebound. Illustrative correlations are: load mass/starting force r≈0.97, radius/constant-speed force r≈0.95, pressure fluctuation/drift r≈0.88, starting force/ease-of-starting rating r≈−0.93, and end-effector inertia/overshoot r≈0.90. Stable relationships consistent with the physical mechanisms support agreement between objective measurements and operator ratings. These coefficients illustrate the analysis method; determine application-specific correlations from larger samples and site measurements.
8.4 Grading method
| Grade | Description | Evaluation guidance |
|---|---|---|
| A | Easy operation, natural response, stable stopping | Improvement target |
| B | Acceptable operation; a few measures need adjustment | Suitable for general handling within the assessed conditions |
| C | Motion is possible but requires noticeable effort or shows drift | Adjust and retest before use |
| D | Pronounced starting effort, drift or impact | Correct before delivery |
Table 8 Proposed operating-feel grades: AUREK research criteria, distinct from an industry standard
09FMEA risk analysis
Drift, rebound, load-switching impact and unintended button actuation affect both operating experience and the safety of people, equipment and workpieces. The table below organizes these risks using failure mode and effects analysis (FMEA). Severity (S), occurrence (O), detection (D) and risk priority number (RPN=S×O×D) are research example values. Project assessments should adjust them using actual fault data, usage frequency and prototype tests.
| Failure mode | Potential causes | Effect on handling feel and safety | S | O | D | RPN | Recommended actions |
|---|---|---|---|---|---|---|---|
| Excessive starting force | Insufficient joint lubrication, bearing contamination, and brake drag | Difficult or jerky starts and increased fatigue | 6 | 5 | 4 | 120 | Check joint resistance and optimize lubrication and braking clearances |
| Large constant-speed force variation | Supply-pressure fluctuation, valve stick-slip or cylinder friction | Unsmooth movement and unstable positioning | 6 | 4 | 5 | 120 | Add pressure records and check pressure reducing valve and compressed-air supply quality |
| Upward/downward drift after stopping | Unsuitable unloaded/loaded pressure settings | Workpiece offset and safety risks | 8 | 4 | 4 | 128 | Establish pressure regulation standards and add stop drift testing |
| Excessive rebound when stopping | High end-effector inertia, insufficient throttling or arm elasticity | Placement impact or assembly misalignment | 7 | 4 | 5 | 140 | Optimize throttling, reduce fixture inertia, and increase buffering |
| Excessive response delay | Long hoses, undersized valve passages or inadequate air supply | Operation lags and cycle time slows down | 5 | 5 | 4 | 100 | Optimize hose length and valve sizing |
| Unloaded/loaded switching impact | Excessive pressure difference or unsuitable control logic | Sudden upward or downward movement | 9 | 3 | 4 | 108 | Verify switching logic and improve the pressure transition |
| Excessive tooling self-weight | Redundant tooling structure or unsuitable material selection | Heavy handling and high inertia | 6 | 6 | 5 | 180 | Reduce tooling weight and bring the center of gravity closer to the flange |
| Air/vacuum hose drag | Improper pipeline layout | Excessive horizontal effort or uneven return motion | 5 | 6 | 3 | 90 | Use cable carriers or rotary unions and improve hose routing |
| Unsuitable handle position | Height, angle or reach does not suit the operator | Wrist and shoulder fatigue | 5 | 5 | 4 | 100 | Redesign handle position using ergonomic criteria |
| Unintended button actuation | Unclear button layout or inadequate actuation safeguards | Unintended tooling motion and safety risks | 9 | 2 | 4 | 72 | Two-button release, separated controls and clear labels |
| Moisture or contamination in the air supply | Insufficient filtration and drainage | Slow valve response or unstable motion | 6 | 5 | 4 | 120 | Increase filter-regulator inspections and establish a condensate-drain interval |
| Insufficient joint damping | Insufficient damping design and large inertia | Poorly controlled horizontal rotation and overshoot | 6 | 4 | 5 | 120 | Add adjustable damping or optimize damping matching |
Table 9 Example operating-feel FMEA using AUREK assessment scores
In this example's RPN ranking, excessive tooling weight (180), excessive rebound after stopping (140) and drift after stopping (128) receive priority in design and commissioning checks. Record each failure mode, corrective measure and retest result together to track resolution. This ranking applies to the example; actual assessment determines project priorities.
10Design and commissioning improvements
Design and commissioning measures can address the pneumatic system, mechanical structure, tooling and ergonomics. The following table lists checks and improvement criteria; specific measures and settings depend on prototype data and customer operating conditions.
| Area | Optimization criteria |
|---|---|
| Pneumatic system | Set suitable regulator range and sensitivity and calibrate pressure. Size the air receiver and check valve to buffer pressure fluctuation. Reduce hose pressure losses, match valve capacity to demand, and provide cushioning and controlled pressure transitions during load switching. |
| Mechanical structure | Reduce joint friction, control clearances and verify full brake release. Improve arm stiffness and avoid sustained operation at limiting positions. Match damping to large-radius conditions to control drift and overshoot. |
| Tooling | Reduce tooling weight and center-of-gravity offset from the flange. Remove unnecessary overhang and improve air/vacuum hose routing. Check center-of-gravity changes throughout turning and provide cushioning or speed limits for high-inertia tooling. |
| Ergonomics | Match handle height to a comfortable elbow position and minimize wrist deviation. Keep buttons within natural reach and protect release controls against unintended actuation. Accommodate operator height differences at frequent-use stations and record height, reach and experience during tests. |
Table 10 Improvement criteria by design area
Use a consistent operating-feel test record for prototype development, site commissioning and customer acceptance, organizing data by load, tooling and conditions. Accumulated records support review of rating weights, grading thresholds and FMEA parameters, as well as subsequent design comparisons and quality-consistency evaluation.
11Conclusions
Key implementation points for operating-feel evaluation are:
(1) Operating force, starting force, constant-speed force, drift, rebound, response delay, pressure stability, joint damping, end-effector inertia and ergonomics form a quantifiable set of engineering measures; evaluations must identify the operating conditions. (2) Force gauges, pressure, displacement and angle sensors, response acquisition and subjective ratings together form the evaluation record: objective tests identify condition and subjective ratings describe experience. (3) Pneumatic balancing pressure is a key check. Unsuitable unloaded or loaded pressures can cause upward motion, sinking, increased starting force or drift. Record pressure, load, radius and operating force together during commissioning and acceptance.
(4) Tooling design must assess weight, center of gravity, inertia, hose drag and dynamic behavior during rotation, as well as grip retention. (5) Evaluate operating feel and safety together, particularly drift, rebound, load-switching impact and unintended button actuation. (6) Retain consistent records of test conditions, measurements and retests to support equipment comparisons and subsequent improvements.
12Reference test records
The PDF appendix provides sample operating-feel records. Copy and adapt them for the prototype, tooling and operating conditions being assessed.
Use a 1–5 rating scale, with 5 as the best score, and define anchors for each measure: ease of starting (1=clearly strenuous / 3=acceptable / 5=light and natural); motion smoothness (1=pronounced jamming / 3=occasional variation / 5=continuous smooth motion); stopping stability (1=pronounced drift / 3=slight drift / 5=stable stop); response (1=clear delay / 3=acceptable / 5=prompt); positioning comfort (1=difficult alignment / 3=achievable / 5=easy positioning); and fatigue (1=pronounced fatigue / 3=moderate / 5=low fatigue). Full sample records are included in the PDF and can be copied to create records for the relevant operating conditions.
