AF-3CR Application · Pilot-Pin Progressive Die
A brushless-motor manufacturer needed to index thin strip at up to 72 mm width and 72 mm pitch. The die uses pilot pins, but the press does not require electrical control of the feed stroke. Those details point to an AF-3C with R-type fixed-clamp release: the AF-3CR.
Thin motor laminations are often discussed as a high-speed production problem. This application starts with a more basic buying question: which compact feeder matches the actual strip envelope, fixed pitch, and die-location method? Selecting on those three facts prevents buyers from overspecifying electronic control or undersizing the feeder.
The confirmed requirement was 0.27–0.35 mm strip, a maximum width of 72 mm, a maximum feed displacement of 72 mm, and a progressive die with pilot pins. HENLI’s published AF reference lists 80 mm maximum width and 80 mm maximum feed length for the AF-3C. The smaller AF-2C is listed at 65 mm maximum width, so it cannot cover a 72 mm strip. The resulting configuration is the AF-3C pneumatic air feeder with the R option, written as AF-3CR.
Why AF-3C Is the Minimum Model for the 72 mm Job
| Selection item | Application | AF reference | Decision |
|---|---|---|---|
| Strip width | Up to 72 mm | AF-2C: 65 mm; AF-3C: 80 mm | AF-3C required |
| Feed pitch | Up to 72 mm per index | AF-3C feed length: up to 80 mm | Within range |
| Strip thickness | 0.27–0.35 mm | AF-3C published maximum: 1.2 mm | Trial required |
| Die location | Pilot pins correct strip position | R option releases the fixed clamp | Specify AF-3CR |
| Feed command | No separate electrical feed signal requested | E option controls feeding electrically | E not required |
Both the width and feed pitch use 72/80, or 90%, of the AF-3C’s listed dimensional capacity. That is a valid model match, but it is not a reason to skip detail checks. Final approval should confirm the real maximum strip-width tolerance, guide clearance, mechanical feed-length adjustment, and whether the complete feed-and-release sequence fits the available press-open time.
What the R-Type Release Does During Pilot Entry
A progressive die can use pilot pins to refine strip position after the feeder has completed its nominal index. The pilots need the strip to move by a very small amount as they enter the previously pierced locating holes. If the feeder’s fixed clamp remains fully locked at that moment, it can oppose the correction and load the strip, pins, or tooling.
The moving clamp grips the strip and advances the mechanically set 72 mm pitch.
The fixed clamp secures the strip while the moving section returns for the next cycle.
The die approaches the strip and its pilot pins begin entering the locating holes.
The R-type solenoid is signalled at the correct press angle and briefly frees the strip.
The pilots make the final small alignment correction without fighting clamp force.
The fixed clamp closes again before the die releases control and the next feed begins.
The R designation therefore describes a specific release function, not a promise of extra feed accuracy by itself. Its value depends on correct mechanical alignment and timing. HENLI’s separate guide explains why pilot release is required in some stamping dies; commissioning must still use the real tool sequence.
Why R Does Not Automatically Mean E or ER
The letters answer two different control questions. E means the feed movement is commanded by an electrical signal. R means the fixed clamp is released for pilot correction. The R function itself uses a solenoid signal, but that does not turn the feed stroke into an E-type electrically controlled feed.
| Configuration | Feed actuation | Fixed-clamp pilot release | Typical reason to choose it |
|---|---|---|---|
| AF-3C | Standard pneumatic/mechanical sequence | No dedicated R release | Fixed-pitch job without an electrical feed command or pilot-release demand |
| AF-3CE | Electrical feed signal | No dedicated R release | The press or controller must determine when the feed stroke occurs |
| AF-3CR | Standard feed sequence | Yes | Fixed pitch with die pilot pins, as in this application |
| AF-3CER | Electrical feed signal | Yes | The application needs both externally commanded feeding and pilot release |
For this buyer, the answer to “Is feeding controlled by an electrical signal?” was no, while the answer to “Does the die have pilot pins?” was yes. That combination selects R without E. Adding E “just in case” would change the control scheme without solving a stated requirement.
How the Feeder Fits a Brushless-Motor Lamination Route
The application is consistent with progressive stamping of thin laminations used in brushless motors. The exact lamination geometry and material grade were not part of the confirmed feeder data, so the feeder should be approved against the production drawing and strip certificate rather than an assumed stator or rotor size.
The 72 mm figure is the maximum strip width and the feed displacement per press cycle. It is not the finished part diameter. A progressive strip layout may include carrier, bridge, edge margin, piercing stations, and more than one feature within each pitch, so the die layout—not the motor model name—sets the feeder stroke.
Protecting 0.27–0.35 mm Thin Strip During Feeding
Model capacity tables usually emphasize maximum thickness. Thin strip creates a different set of risks: it can mark, buckle, or slip before the feeder reaches its nominal load limit. If the job uses coated electrical steel, the supplier and buyer should also verify that the accepted pressure and guide settings do not cause unacceptable coating damage. That material description must come from the buyer’s certificate; it should not be inferred from thickness alone.
Clamp force and surface contact
Begin with the lowest stable pressure that completes the feed without slip. Inspect both strip faces after repeated cycles, not only after one manual index. Oily stock, coating condition, hardness, and contact geometry can change the acceptable setting.
Guide clearance and strip flatness
Align the feeder and die centreline before tightening the mount. Set the lateral guide wide enough for real edge and burr variation but close enough to prevent wandering. Verify that the upstream straightener does not introduce crossbow or excessive tension.
Clean, stable compressed air
Use dry, filtered, regulated air at the specified supply conditions. Pressure drop, water, leaks, restricted fittings, or inconsistent valve response can change clamp handover and release timing at production speed.
Pilot holes and release window
Inspect pilot-hole quality, burr direction, pin condition, and entry angle. Release only for the interval required for correction, then confirm that the clamp re-engages before the next feed cycle.
A successful slow jog proves access and basic motion; it does not prove repeated 72 mm feeding under production conditions. HENLI’s pneumatic-feeder timing guide covers the generic press sequence. Acceptance for thin motor-lamination strip should include restarts, extended cycling, surface inspection, pitch measurement, and pilot engagement with the production die.
When to Keep the Air Feeder—and When to Compare Alternatives
AF-3CR remains a practical fit when
- The die uses a stable 72 mm-or-shorter pitch.
- The verified press window allows the pneumatic stroke to complete.
- The strip can be gripped repeatedly without unacceptable marking or slip.
- The pilot-release signal can be timed reliably to the die.
- The plant values a compact, mechanically adjusted feeder for a dedicated job.
Compare another feeder when
- Operators change feed pitch frequently across many dies.
- Recipes, programmed multi-step feeding, or electronic length changes are required.
- The press-open feed window is too short for the validated pneumatic cycle.
- Strip grip or surface protection cannot be stabilized with trials.
- The application needs a different high-speed feeding principle.
For frequent recipes and programmed motion, compare an NC servo feeder. For suitable continuous high-speed press work, a high-speed roller feeder may be evaluated. The choice should follow the real strip, pitch, press timing, and die—not the product label alone.
AF-3CR Commissioning Checklist
Record grade, thickness range, coating or surface condition, hardness, width tolerance, burr direction, and coil condition.
Verify maximum real strip width and maximum pitch against AF-3C guide clearance and mechanical stroke adjustment.
Size the decoiler, straightener, and loop control separately so the feeder does not pull coil inertia.
Set height, centreline, inlet rollers, side guide, and mounting rigidity before powered production trials.
Confirm moving-clamp grip, fixed-clamp hold, return stroke, and no rollback through repeated starts and stops.
Release the fixed clamp during pilot entry, then verify re-clamping before the strip is handed back to the feeder.
Check marking, slip, pitch, pilot holes, edge margin, burr, scrap exit, and any coating damage defined by the buyer.
Run the actual material and die at the intended speed; document pressure, guide, stroke, and timing settings after acceptance.
Buyer Questions About This AF-3CR Application
Why use AF-3C instead of AF-2C for this motor-lamination job?
The strip can reach 72 mm wide, while HENLI’s AF reference lists AF-2C at 65 mm maximum width. AF-3C is listed at 80 mm width and 80 mm feed length, so it is the minimum model in the range that covers both the 72 mm width and 72 mm pitch.
Why does the feeder need the R option?
The progressive die uses pilot pins. The R-type solenoid briefly releases the fixed clamp during pilot entry, allowing the pins to make a small final strip-position correction without fighting the clamp.
Does R-type release replace E-type electrical feed control?
No. E controls when the feed stroke is commanded; R releases the fixed clamp for pilot correction. An R circuit uses an electrical solenoid signal, but the feeder is still AF-3CR—not AF-3CE or AF-3CER—when electrical control of the feed stroke is not required.
Can the AF-3CR pull the strip directly from a coil?
It should not pull coil inertia directly. Use suitable payoff, straightening, and loop control so the feeder receives prepared strip with stable upstream tension.
Can 0.27 mm strip be fed without marking or slipping?
It may be feasible, but thickness alone cannot guarantee surface results. Trial the actual grade and surface condition, begin with the lowest stable clamp pressure, and inspect marking, slip, pitch, pilot correction, and any specified coating condition through an extended run.
Related HENLI Equipment
NC Servo FeederProgrammable feeding for frequent pitch changes, recipes, and electronically controlled motion.
Decoiler MachineControl coil payoff upstream so the feeder indexes prepared strip from a stable loop.
Confirm the AF-3CR With Your Strip and Die Data
Send HENLI the material certificate, width and thickness range, feed pitch, strip layout, die drawing, pilot-entry sequence, press speed and angle diagram, air-supply details, and upstream coil arrangement. We will check AF-3CR capacity and timing or compare another feeding method where the application requires it.
Request an AF-3CR Application Review
Read the Air Feeder Selection Guide
