In the production of electric heating elements, the quality of a coil is determined at two moments: when it is wound and when it is cut. An irregular winding or an imperfect cut is all it takes to compromise the next stage. This affects everything from welding the terminal pins to inserting the coil into the tube. The CSM coiling machine, a resistance wire coil winding machine for tubular heaters, is designed to handle both moments with the same care. In particular, it delivers a clean cut with no curl and consistent winding from the start of production to the end.
Curl-free cutting: clean ends, coils ready to use
The first advantage customers notice is that there is no curl at the end of the coil. With our coiling machine, coils that come out with a curl are the exception. Moreover, simply trimming the ends is enough to recover them: no scrap, just a quick touch-up. As a result, less time is spent on inspection and more coils are ready for the next stage.
The credit goes to the pre-cutting system and how easy it is to adjust. In fact, the blade position is set electrically with just two buttons (up and down). What’s more, it can be corrected even while the machine is running, without stopping production. Thanks to this, the operator watches the result and fine-tunes the setting in real time. There is no need to work by trial and error with the machine stopped.
In addition, the blade features a carefully engineered mechanical solution: a special clearance that allows it to rotate by friction. This way, the blade cuts the wire from below, exactly between two turns of the coil. Consequently, it leaves a clean end with no deformation. Finally, the blade is driven by a DC motor, which ensures controlled, repeatable movement on every cycle.
Continuous, consistent winding: three motors, one rhythm
A good cut is only worth something if the winding before it is regular. That is why the coiling machine is equipped with three individually controlled DC motors. The winding motor acts as the master. The feed wheel motors, on the other hand, are slaves: they follow the master at a ratio that the operator can set freely.
Consequently, the system responds in a coordinated way. When the mandrel speed is increased (or reduced), the other motors adjust automatically, keeping the set ratio unchanged. Thus, the wire is always fed at the right speed, cycle after cycle, with no jerks and no variations in tension.
Furthermore, stability over time is another key advantage. Because the speeds are controlled electrically, they are not subject to the drift typical of mechanical systems. These systems rely on clutches and a single motor, so they tend to change behaviour as they wear and heat up. In contrast, with electrical control, the coil produced at the start of a shift is identical to the one produced at the end. It also matches the coils in the next batch.
Why choose an electronically controlled coil winding machine
Cutting and winding are two sides of the same philosophy: keeping variability to a minimum. A pre-cut that can be adjusted in seconds and a blade that always works the same way ensure a consistent cut. At the same time, three motors keep the winding rhythm constant. Together, they produce perfect, repeatable coils with less scrap and fewer operator interventions.
Ultimately, for series producers of electric heating elements, this means greater production continuity, more consistent quality and shorter inspection times.
Want to see the coiling machine in action? Watch the machine video or contact us for a demonstration or to find out more about the technical features of our models.