Which Servo Feeder Mounting Suits a 200 SPM Press?
A servo feeder can hang on the press uprights or stand on its own foundation, and the choice is usually made by whoever draws the layout rather than by whoever runs the line. Both arrangements feed strip.
They fail differently.
On a 200 SPM press with a 1,300 mm coil, the difference shows up in three places: pass-line stability, access to the die, and how long an alignment lasts.
This is the comparison we walk through with buyers before a press interface is drawn, including the case where neither mounting is the right answer.
Two Places to Put a Feeder, and One That Fits
Press-mounted means brackets bolted to the uprights or to the bed extension, with the feeder cantilevered into the die area. The feeder travels with the press frame.
Floor-mounted means a separate base, grouted to its own slab, with the feeder aligned to the press once and checked on a schedule.
The third arrangement, a feeder built into a bed extension that is part of the press, is really a variant of press-mounted and inherits its behaviour.
Most misunderstandings start here: press-mounted is not "closer to the die". Both arrangements put the feed rolls within 300 mm of the die face.
What changes is what happens to that distance when the press is running.
What Press-Mounted Buys You
Pass line that does not drift. The feeder and the die share one frame, so a press that settles 0.2 mm takes the feeder with it. Feed height relative to the die stays where it was set.
No separate foundation. That removes a civil works item, a grout cure and a second alignment from the installation schedule. On a line being installed inside an existing building, it can save two weeks.
About 1.2 m of floor. On a plant where the coil line is being squeezed between two presses, that metre is sometimes the reason the layout passes.
Fewer alignment checks. One alignment at commissioning instead of a quarterly check, because there is no relative movement to chase.
The cost side starts with mass. A 1,300 mm feeder with rolls and a drive weighs 3.5 to 4.5 tonnes, and that mass hangs on brackets that were never part of the press designer's load case.
What Floor-Mounted Buys You
Isolation from press deflection. A press crown deflects under load, and the uprights move with it. A floor-mounted feeder does not, so the feed rolls see a stable reference while the press works.
Service access. Rolls, belts, encoders and the drive are reachable from three sides. On a press-mounted unit, one side is the press frame and the other is the die area.
Retrofit freedom. A floor-mounted feeder can be re-aligned, re-shimmed or moved to another press. A press-mounted one is tied to the frame it was drilled into.
Mass goes into the ground. The feeder's weight and its vibration land on a foundation designed for them, not on the press uprights.
The cost is the foundation itself, plus the alignment that has to be maintained. On a press that has been in service for twenty years, the floor under it may also be the reason the feeder drifts.
The Tradeoff in One Table
Read the third column first. It is where the decision actually gets made, and it is the column that tends to be missing from a supplier's comparison.
| What the arrangement gives | Press-mounted | Floor-mounted |
|---|---|---|
| Pass line against the die | Held by the press frame, no drift | Held by the foundation, drifts if the slab moves |
| Installation time | Two days, no civil work | One to two weeks including grout cure |
| Floor space | Saves about 1.2 m | Needs its own footprint and access aisle |
| Where it charges you | 4 t of feeder mass on uprights that were not designed for it | A foundation and a quarterly alignment check |
| Service access | Two sides, one of them the die area | Three sides, rolls out in under an hour |
| Moving to another press | Not practical without new brackets | Straightforward |
On a 200 SPM press the mass question is not academic.
Upright brackets carry static load plus a dynamic component from the feeder's own acceleration, and a press builder asked to approve 4 tonnes on a frame designed for tooling will usually refuse.
That refusal is often the whole decision. If the press manufacturer will not sign off the brackets, the feeder goes on the floor regardless of how good the layout looked.
Six questions come up whenever this comparison is put to a buyer.
How much feeder mass can a 200 SPM press upright carry?
Typically 1.5 to 2.5 tonnes on brackets the builder approves, against a 4-tonne feeder. Above that the brackets need a designed load case, not a standard kit.
How much floor does a press-mounted feeder actually save?
About 1.2 m of line length and the whole access aisle behind it. On a 6 m line that is 20 percent of the footprint.
How often does a floor-mounted feeder need re-alignment?
Every 3 months for the first year, then annually if the slab is stable. Check the pass line within 0.1 mm and the square within 0.05 mm per metre.
Does press crown deflection move a floor-mounted feeder's reference?
No, and that is the point. A 200-tonne press can deflect 0.15 mm at the crown under load while a floor-mounted feeder stays where it was grouted.
At what feed length does mounting choice stop mattering?
Below about 40 mm the feed is short enough that pass-line error contributes less than roll grip. Above 150 mm the alignment dominates the error budget.
Can a press-mounted feeder hold ±0.05 mm at 200 SPM?
Yes, on a press whose uprights are stiff enough. The tolerance is achievable both ways; what differs is how often it needs to be re-proven.
The Numbers That Separate Them
Four measurements decide whether the difference is real on a specific press. Ask for them in the technical offer rather than after installation.
| Measurement | Press-mounted result | Floor-mounted result |
|---|---|---|
| Pass-line change at full tonnage | 0.02 to 0.05 mm, follows the frame | 0.00 to 0.02 mm |
| Vibration at the feed rolls, 200 SPM | 4 to 9 µm, transmitted through the brackets | 1 to 3 µm on an isolated base |
| Roll change time | 90 to 150 minutes | 45 to 70 minutes |
| Time to re-prove accuracy after a die change | 5 minutes | 10 to 15 minutes |
The vibration row explains most of the quality complaints that get blamed on the feeder. Strip fed into a roll gap that is moving by 9 µm produces a length variation that no tuning removes.
On a press running thin material at 200 SPM, 9 µm of roll vibration can show up as 0.04 mm of length scatter. That is most of a ±0.05 mm budget spent before the feeder has done anything wrong.
Where Neither Mounting Works
Four press types make this comparison irrelevant, and it is worth naming them before a layout is fixed.
Presses with a pit. If the bed sits 800 mm below floor level, a floor-mounted feeder needs its own plinth and the pass line arrives at an awkward height. Press-mounted is usually the only practical answer.
Tall dies and long shut heights. A die that needs 500 mm of shut height pushes the feeder further from the press centre, and the cantilever on a press-mounted bracket grows with it.
Past about 700 mm of reach, deflection stops being negligible.
Transfer and progressive lines with in-press automation. The space between the uprights is already occupied. A feeder that needs to reach into that space will conflict with the transfer rails.
Coil wider than 1,400 mm. At that width the feeder mass passes 6 tonnes and the roll span makes the frame itself the dominant deflection source. Neither mounting solves a frame that flexes.
There is also the honest case: a press whose foundation is unknown.
On a 30-year-old press with no drawing of the slab, a floor-mounted feeder is a gamble on concrete, and a press-mounted one is a gamble on the frame. Ask for a core test before choosing.
Deciding With Three Measurements
Three numbers on the press drawing settle it in an afternoon, and none of them requires the feeder to be delivered.
- Upright stiffness at the bracket height, from the press builder. Below 200 kN/mm, a 4-tonne feeder will move the frame measurably.
- Crown deflection at rated tonnage. Above 0.1 mm, a press-mounted feeder inherits that movement into the pass line.
- Slab condition and thickness under the proposed foundation. Below 200 mm of reinforced concrete, the floor option needs a plinth.
Where the press builder cannot supply the first two numbers, treat that as an answer. A frame with no stiffness data is not a frame to hang 4 tonnes on.
Mounting dimensions, bracket options and feeder masses for our builds are listed on the feeder data library, which a press builder needs before approving a bracket design.
What Changes After Two Years
The mounting decision is made once and paid for over a decade. Three things shift with time.
Bracket bolts relax. A press-mounted feeder's brackets need their bolts checked at the first service and annually after that. A 4-tonne mass on a vibrating frame finds loose fasteners.
Foundations settle. A floor-mounted feeder on a new slab will move in the first year and then stop. That is why the first-year alignment schedule is quarterly rather than annual.
Dies get taller. A line specified at 320 mm shut height and later running 400 mm dies needs the feeder to move back. On a floor-mounted base that is a shim and a re-alignment. On brackets it may mean new brackets.
None of this argues for one arrangement over the other.
It argues for writing the service schedule into the purchase, because the arrangement that is cheaper to install is rarely the one that is cheaper to keep accurate.
Where to go next
Mounting sets the reference frame for every feed decision after it, and the accuracy that follows from that reference is budgeted line by line rather than bought as a single number.
Our coil line knowledge base takes that budget apart from the coil to the die, so a mounting choice can be priced against the error it actually contributes.
