Ask two stamping shops what feeder to put on a press and you will often get two confident, opposite answers. That is because the right answer genuinely depends on the job — and the cost of getting it wrong is real. An undersized or imprecise feeder caps the press speed and scraps parts; an oversized one ties up capital that the work never repays. This guide walks the three real options and the parameters that decide between them.
Option 1 — The pneumatic air feeder
The air feeder is the workhorse of simple stamping. It advances the strip with a pair of pneumatically actuated clamps: a gripper clamps the strip and pulls it forward by a set distance, a second clamp holds while the gripper returns, and an adjustable mechanical stop fixes the feed length. There is no servo, no controller — just air, valves and a stop.
What it is good at: low purchase cost, mechanical simplicity, easy maintenance, and genuinely fast cycling for short, fixed feed lengths. For a press running a single job with a modest, unchanging progression, an air feeder is often the correct and economical answer. Its limits are the flip side of that simplicity: the feed length is set by a physical stop, so every pitch change is a manual re-set; accuracy and repeatability are good but not servo-grade; and feed pitch, material width and thickness are all bounded.
Option 2 — The NC servo roller feeder
The NC servo roller feeder advances the strip between a pair of servo-driven rollers. The feed pitch is entered digitally on a controller, the servo turns the rollers exactly that far, and the feeder takes a cam or encoder signal from the press so it feeds in the right window of the stroke. There is no mechanical stop to re-set — a job change is a number on a screen, or a stored recipe.
That is the whole case for it. Precision and repeatability are servo-grade, which matters for pilot-hole alignment on progressive dies. The feed pitch can be long and can vary part to part. Wider and thicker material is within reach. Job changeover is fast, which is decisive in a shop that runs many short jobs. The NC servo feeder is the right choice whenever accuracy, flexibility or throughput matter — which, for most modern stamping, is most of the time. The cost is real but it is repaid in scrap reduction, faster changeovers and higher sustainable press speed.
Option 3 — The 3-in-1 coil line
When the press runs from coil rather than pre-cut blanks, the feeder is only one third of the problem. The coil also has to be unwound and it has to be flattened — coil stock carries a curve (coil set) that must be levelled out before the strip enters the die. The 3-in-1 coil line integrates all three functions: decoiler, straightener and NC servo feeder, built and controlled as one matched machine.
The reason to buy it as a unit rather than three separate machines is integration: one control system, guaranteed speed synchronisation between the decoiler, straightener and feeder, less floor space, and simpler wiring. For medium-to-high-volume coil-fed stamping it is the standard, and trying to assemble an equivalent from mismatched parts usually costs more in commissioning headaches than it saves.
The comparison at a glance
| Factor | Air feeder | NC servo feeder | 3-in-1 coil line |
|---|---|---|---|
| Feed pitch setting | Mechanical stop, manual | Digital, programmable | Digital, programmable |
| Pitch accuracy | Good (fixed jobs) | Servo-grade, high | Servo-grade, high |
| Job changeover | Slow (manual re-set) | Fast (recipe) | Fast (recipe) |
| Material range | Narrow / thin, short pitch | Wide range | Wide range, coil-fed |
| Handles coil + straightening | No | Feeder only | Yes — integrated |
| Relative cost | Lowest | Medium | Highest |
| Best fit | Simple, fixed, short-run work | Precision, mixed jobs, blanks or coil | Volume coil-fed production |
How to actually choose — four parameters
Strip away the marketing and the decision comes down to four numbers, measured against the feeder’s rated capacity:
- Material width and thickness — sets the mechanical capacity the rolls or grippers must have.
- Feed pitch and required accuracy — long or variable pitch, or tight tolerance, points to a servo feeder; a short fixed pitch with loose tolerance allows an air feeder.
- Press speed (SPM) and the feed window — the feeder must complete its advance and settle the strip within the angular slice of the stroke available before the tooling descends.
- Coil or blank, and job mix — coil-fed volume work wants a 3-in-1 line; frequent job changes reward the servo feeder’s fast changeover.
Our own rule of thumb: if the job is genuinely simple, fixed and short-pitch, an air feeder such as the DAIDISIKE A50 / A100 / BX150 is the honest, economical choice and we will say so. The moment accuracy, flexibility or throughput enter the picture, the NC servo feeder pays for itself — and for coil-fed volume production, the integrated 3-in-1 line is the right tool. Match the feeder to the job, not to the brochure.