Strapping/Banding Machine Not Feeding Strap
No strap coming through usually comes down to one of four things: the coil, the threading path, the feed rollers, or the sensor that tells the machine whether strap is present. Most can be checked quickly without tools.
Common symptoms
Whether the motor is running or not tells you a lot. If it's running but no strap moves, the problem is mechanical. If nothing happens at all, the fault may be electrical or sensor-related.
Motor runs but no strap moves
The drive is active but strap isn't moving. Either the strap isn't engaged with the feed rollers, or the rollers are worn and slipping on the strap surface.
Strap comes partway through then stops
A partial feed that stops at the same point each time points to an obstruction at that location. A partial feed that stops at different lengths suggests roller slip or strap condition.
Nothing happens when the machine starts the feed cycle
No motor sound, no movement. The feed motor may have a fault, or a safety interlock is preventing the feed from initiating. Check for active alarms before assuming motor failure.
Machine shows strap-out alarm but the coil is full
The strap-out sensor is triggering incorrectly. It either can't see the strap in the correct position, or the sensor itself has developed a fault.
Strap reverses instead of feeding forward
The machine is running a retract cycle when it should be feeding. Often a threading issue - the strap isn't positioned correctly for the machine to recognise a forward feed is needed.
Feed works on the first cycle after a new reel, then fails
The strap wasn't pulled through fully when loaded. The first feed runs from what's already in the guide path, then fails when it tries to draw from the coil directly.
Typical causes
Strap not threaded correctly or coil not seated
Incorrect threading is the most common cause of feed failure after a reel change. The path through rollers, guides and sensors is specific to the machine model. A strap that's out of path at any point will cause a feed failure.
Worn feed rollers
The rollers that grip the strap to drive it forward wear over time and lose their grip. Worn rollers slip rather than drive, producing partial feeds that stop at inconsistent lengths or no feed at all.
Strap-out sensor fault
The sensor detecting whether strap is present in the guide path is stuck in the "strap absent" state. The machine won't start the feed cycle because it believes there's no strap available.
Feed motor fault
The motor driving the feed mechanism has failed or is failing. A motor that runs but produces no torque won't move the strap. A motor that doesn't run at all points to an electrical fault upstream of it.
What to check first
Threading is the most common cause after a reel change. Start there before looking at anything mechanical.
Check the coil and threading path
Confirm the coil is seated correctly on the spindle and hasn't locked up or spooled loose. Then trace the strap path through every guide, roller and sensor point. A strap out of path at any single point will cause a complete feed failure.
Re-thread from scratch
Remove the strap from the machine and re-thread it from the beginning using the machine's threading diagram. Do this slowly. It's the most reliable way to rule out a threading problem, which is the most common cause of a feed failure after a reel change.
Check the strap-out sensor
Manually position strap in front of the sensor and watch whether the alarm clears. If it does, the strap was out of position. If the alarm stays on with strap correctly positioned, the sensor may have failed.
Listen to the feed motor during a cycle attempt
Is the motor running? Does it sound strained? No sound means no power to the motor or complete motor failure. A motor running without moving strap means either roller slip or a jam the motor can't get through.
If any of these apply, don't wait
- Feed rollers are visibly worn or strap is slipping on the drive surface
- The strap-out sensor won't clear when strap is correctly positioned in the guide path
- The feed motor isn't running despite confirmed power reaching the machine
- Re-threading hasn't resolved the fault after a reel change
If you've re-threaded correctly and confirmed the coil is seated but still getting no feed, the fault is mechanical. Roller wear and motor faults won't resolve with adjustments.