Metal Framing ยท Upstream Coil Payoff
A metal stud and track roll forming machine needs a stable supply of narrow coil strip before profiling, punching and cut-off can stay consistent. This guide evaluates an 800 kg double-head decoiler reference configuration for 1.2 mm strip up to 235 mm wide and a target line speed of 40 m/min.
The decoiler does not form the C or U profile. Its job is to support the coil and release strip into the roll-forming section without uncontrolled overrun, excessive drag or unstable entry alignment. That upstream behavior affects how smoothly the roll former accelerates, stops and restarts.
The reference machine shown here uses two coil positions, hydraulic mandrel expansion and pneumatic disc braking. It is a non-motorized, pull-through arrangement: the downstream roll former or another traction unit must provide the force that turns the active coil. That can be a practical solution for compatible metal stud and track lines, but only after pull capacity, coil inertia, strip condition and speed profile are checked.
Reference Coil-Payoff Configuration
The following data describes the available double-head decoiler, not a universal specification for every stud and track roll forming machine. The correct coil capacity and control method must be matched to the buyer’s profile range, material and production schedule.
| Item | Project specification | What it means in production |
|---|---|---|
| Decoiler layout | Double head, non-motorized payoff | One spindle supplies the roll former while the idle spindle can be prepared with the next coil. |
| Maximum coil weight | 800 kg per working position | Confirm that the real master coils do not exceed the rated load, including any lifting attachment or adapter requirements. |
| Reference strip | 1.2 mm thick, up to 235 mm wide | Potentially suitable for light-gauge framing profiles when the material grade and downstream traction are compatible. |
| Coil dimensions | 430 mm ID, up to 1150 mm OD | Hydraulic expansion grips the specified coil bore; mismatched IDs require a different mandrel range or adapter assessment. |
| Target line speed | Up to 40 m/min | The stated speed is a system target, not a stand-alone guarantee from the decoiler. |
| Payoff control | Pneumatic disc brake | Adjustable resistance helps control coil overrun while the roll former pulls strip forward. |
| Utilities | 380 V / 50 Hz plus compressed air | Power serves hydraulic and control functions; compressed air operates the brake circuit. |
| Coil loading | No coil loading car included | The plant must provide a rated crane, forklift or another approved lifting arrangement. |
Where the Decoiler Fits in a Stud and Track Roll Forming Line
A typical metal framing line begins with coil payoff and then guides the strip into the forming process. Depending on the product and machine design, the line may also include straightening, servo feeding, pre-punching, in-line punching, roll forming, flying or stop-to-cut shearing and automatic collection. The exact sequence varies, but stable strip entry is required before the forming stands can maintain a repeatable profile.
Coil support
The mandrel carries the coil and keeps its bore centered so the strip enters the guide path from a predictable position.
Payoff resistance
The disc brake resists free spinning when the roll former decelerates, helping to prevent loose wraps and excess strip release.
Changeover preparation
Operators can load and expand the next coil on the idle spindle while the active coil continues supplying the line.
System compatibility
The roll former must have enough traction for passive payoff, or the line needs motorized unwinding and loop control.
For the general equipment decision across other profiles, see HENLI’s decoiler selection guide for roll forming machines. This page focuses specifically on the narrower metal stud and track application.
Can the Roll Former Pull a Non-Motorized Decoiler?
Possiblyโbut the answer comes from a force and process check, not from strip thickness alone. In a passive arrangement, the roll-forming machine supplies the force required to overcome bearing resistance, brake drag and the changing rotational behavior of the coil. The strip must transmit that force without slipping in the traction rolls, stretching, marking or losing alignment.
Passive payoff is more likely to work when
- The roll former has proven traction capacity for the full coil condition.
- The strip path is short, direct and properly guided.
- Starts and stops are controlled rather than extremely abrupt.
- The material surface can tolerate the required traction without marking.
Motorized payoff is safer when
- The roll former should not carry the coil’s rotational load.
- The line needs a controlled loop between payoff and forming.
- Frequent speed changes create unstable tension.
- Thin, sensitive or high-strength strip is difficult to pull consistently.
Once the line accelerates the strip, the 800 kg coil and mandrel store rotational energy. When strip demand stops, the rotating mass cannot stop instantly on its own. The pneumatic disc brake must provide enough resistance to limit overrun without forcing the roll former to pull against unnecessary drag. HENLI’s decoiler brake and tension setup guide explains the broader adjustment principles.
Hydraulic Expansion for 430 mm Coil ID
โNon-motorizedโ describes the payoff motion: no drive motor rotates the mandrel to release strip. It does not mean every machine function is manual. The hydraulic power unit expands and retracts the mandrel segments around the specified 430 mm coil ID, while the electrical and pneumatic circuits serve the auxiliary functions.
Bring the coil squarely to the idle spindle with the approved external lifting device and align the coil ID with the mandrel.
Hydraulic movement pushes the mandrel segments outward to support the coil ID and establish a stable rotational center.
Confirm full seating, retaining devices and clearance before removing the lifting equipment or releasing the coil restraint.
Adjust air pressure and disc-brake response so the strip pulls smoothly without uncontrolled mandrel rotation.
The 380 V / 50 Hz supply is therefore compatible with passive payoff: it powers the hydraulic and control functions, not an active mandrel drive. The pneumatic disc brake also requires a clean, stable compressed-air supply at the specified plant pressure.
Why Two Coil Positions Help Stud and Track Production
Stud and track lines often run repetitive profiles from narrow coils. A single-head decoiler requires the active coil to finish before the same spindle can be cleared, loaded and expanded. A double-head arrangement moves much of that preparation into the running period.
The production-side spindle supplies strip under pneumatic brake control.
During production, load the idle spindle, expand the mandrel and confirm coil retention.
When the active coil is complete, follow the machine’s indexing and locking procedure to place the prepared coil on the roll-former centerline.
Guide the new strip into the downstream machine, confirm brake response and resume production.
The practical gain is shorter coil preparation during the production stop. The arrangement does not create automatic or zero-downtime changeover: spindle indexing, strip threading, profile setup, length-program confirmation and restart still follow the line’s normal procedure.
Site Conditions When No Coil Car Is Supplied
Specifying the decoiler without a loading trolley keeps the machine package simpler, but it transfers coil handling to the buyer’s workshop. The site must provide a safe method to lift an 800 kg coil, align it with either spindle and withdraw the lifting device without striking the frame, hydraulic unit or adjacent equipment.
| Site item | What to confirm before installation |
|---|---|
| Lifting equipment | Crane, forklift, C-hook, sling or other approved device with sufficient rated capacity for the coil and lifting attachment. |
| Approach path | Clear access to both loading positions, including turning radius, aisle width and overhead clearance. |
| Spindle center height | The lifting method must place the coil ID on the mandrel centerline without dragging the coil across the expansion segments. |
| Floor and anchoring | Level foundation, machine fixing points and enough bearing capacity for the decoiler plus the loaded coil. |
| Operator zone | Safe access for expansion, retention, strip threading and brake adjustment while keeping personnel out of suspended-load and pinch-point areas. |
| Utilities | 380 V / 50 Hz electrical supply, hydraulic service access and stable compressed air routed away from the strip and loading path. |
Commissioning Checklist for Pull-Through Payoff
Confirm material grade, width, thickness, actual weight, ID, OD, winding direction and surface requirements.
Set the active spindle to the downstream centerline and check guides, entry height and clearance through the complete route.
Expand and retract with an unloaded spindle first, then confirm full coil seating and retention after loading.
Apply enough air pressure to prevent free rotation, then increase only as required during pull-through testing.
Check slow jog, normal speed, short stops, emergency stops and restarts with both large- and small-diameter coil conditions.
Save brake pressure, material data, feed direction and changeover steps for each approved coil program.
Match the Decoiler to the Actual Profile Program
| Buyer data | Why HENLI needs it | Decision affected |
|---|---|---|
| Stud and track sizes | Profile width and developed strip width may differ substantially. | Mandrel face, strip guides and maximum usable width. |
| Steel grade and coating | Yield strength and surface sensitivity change the required traction and acceptable contact. | Passive versus motorized payoff and guide design. |
| Thickness range | A line that occasionally runs thicker material cannot be selected only around the common 1.2 mm program. | Pull-force margin, straightening and brake adjustment. |
| Coil weight, ID and OD | All three dimensions affect mechanical fit, rotating inertia and lifting. | Frame capacity, mandrel range, brake and loading method. |
| Real production speed | Maximum catalog speed does not describe acceleration, stop frequency or cut-off cycle. | Brake response, loop control and motorized-payoff need. |
| Roll-former traction data | Passive payoff transfers the unwinding load to the downstream machine. | Whether the 800 kg non-motorized reference configuration is suitable. |
There is no universal advantage to passive or motorized payoff. The correct choice depends on coil inertia, downstream pull, material behavior, speed profile and available loop space. Review HENLI’s hydraulic expansion decoiler guide for additional mandrel and coil-ID checks.
Frequently Asked Questions
What is a metal stud and track roll forming machine?
It is a production line that continuously forms coiled sheet into light-gauge framing profiles such as studs and tracks. A typical line combines coil payoff, guiding or leveling, optional punching, roll forming, length control, cut-off and collection.
Does every stud and track roll forming machine need a double-head decoiler?
No. A single-head decoiler may suit lower-volume work or longer coil runs. A double-head arrangement is useful when the next coil should be loaded and secured while the current coil remains in production.
Can the roll former pull a non-motorized decoiler at 40 m/min?
It can when the roll former has sufficient traction and the brake, strip path, coil inertia and start-stop cycle are matched. The 40 m/min target must be proven with the actual material and full production sequence.
When should a stud and track line use a motorized decoiler?
Choose motorized payoff when the roll former should not carry the coil load, traction is limited, a controlled loop is required, speed changes are frequent or the material is difficult to pull without marking or tension variation.
What information is needed to quote the coil-payoff section?
Provide profile drawings, developed strip width, material grade and coating, thickness range, coil weight, ID and OD, target speed, start-stop pattern, roll-former traction data, loading method, feed direction, power, air supply and a dimensioned layout.
Related HENLI Equipment
Roll Forming Decoiler GuideReview general uncoiler choices across roll-forming materials, coil weights and line layouts.
Decoiler MachineCompare passive, motorized and hydraulic coil-payoff configurations.
Configure Coil Payoff for Your Stud and Track Line
Send HENLI the stud and track profile drawings, developed strip width, material grade, thickness range, coil weight, ID and OD, target speed, roll-former traction data, loading method and plant layout. We will check whether passive payoff is appropriate and match the mandrel, brake and double-head arrangement to the upstream coil section.
