YongSheng is an industry leader that offers you all types of constant force springs, These include heavy-duty load constant force springs, constant torque springs, laminated constant force springs and multiply loaded constant force springs.

Due to different sizes and mounting ways, it’s quite simple to mount them to any existing hardware.

They help in avoiding the use of complex motors which are expensive. You can mount these springs in several ways.

You can mount these springs in several ways, and this article will teach you how to mount your constant force springs step by step.

Drum Mounting Method


As the name indicates, the spring is attached to a rotating drum.

This method guarantees the longevity of your springs, the axis enables the springs to become tolerable to repeatable operations.

However, make sure the surface of your drum is smooth, this helps to reduce friction.

The steps to mount are as follows:

  1. Ready your drum or spool for mounting, The drum should be rotating on an axis. Ensure the drum diameter is larger than the spring’s inner diameter, the drum should be greater by 15%-20%. For example, suppose the nominal diameter of your spring is 1.5 inches, the drum’s diameter could be about 1.7 inches. This ensures that your spring fits tightly.
  1. Next, you need to expand the spring’s inner diameter. This is achieved by holding back the inner end then extending back the outer end.
  1. Slide the spring into place. Ensure that the spring is slotted well. To wrap the spring properly, attach your rotating drum tightly to the inner diameter of your constant force spring.
  1. Alternatively, you could reverse the spring. This makes the inner end become the outer end. The inner diameter of the spring is exposed and you are required to place your drum over it. Rewind the spring back to its initial orientation. The spring is therefore tightly wound over the rotating drum. Care should be taken not to bend the spring over its original curvature.
  1. Finally, attach the free terminal of the spring to your desired load force. Tension forced on the spring causes the axis on the drum to rotate.
  1. Always ensure that there are at least one and a half coils held by the drum when the spring is at full extension. If not properly done, it may lead to your spring’s misalignment. The spring may come off the drum.

You must make sure that your axis rotates smoothly.  This is important because it ensures that your spring has a long lifespan.

Cavity Mounting Method


This method is simple yet inexpensive. It also decreases the number of parts you need to assemble. See the following steps for accurate mounting:

  1. The initial step involves preparing your cavity. It needs shaping like the cross-section of a cylinder. You could make your cavity from a metal or plastic block. This is solely dependent on your application.
  1. Make sure that the inner diameter of the cavity is marginally greater than the spring’s outer diameter. This guarantees that your spring fits perfectly in the cavity. A loose fit will cause unreliability in operations.
  1. Make a gap at the top of your cavity. This will make it possible to extend your spring from the cavity to your loading force.
  1. Carefully smoothen your cavity. This will help reduce friction when the spring extends and recoils regularly. Reduced friction increases the lifespan of your spring.
  1. Slot your spring into the cavity. Ensure that the spring fits tightly and can still rotate in the cavity.
  1. Guide the free end of the spring towards your loading force through the gap. Attach the spring to your application.
  1. Ensure that your spring is secure in the cavity. The extended part should be guided properly. This helps to avoid bending and twisting of your spring.
  1. Friction in this mounting method causes a reduction of the life-span of the spring. To combat this drawback, you could add some lubricating oil.


Various Multiply Load Force Mounting

Multiply load force mounting can increase the load force, Yongsheng has various kinds of ways for multiply load force mounting, like laminated mounting, back to back mounting, and tandem mounting.

Laminated mounting is winding 2 spring to 1 in the mounting process, this method will offer almost double force in the voyage, this mounting method is mainly used in limited room and needs bigger force.


Back-to-back mounting is fixed at the end of 2 single constant force spring back to back, just like the image below, this method can increase force in a very stable status.


Tandem mounting is very common is the application, it’s easy to increase force via add spring, in theory, we can add numberless springs in the limitless room to increase the force by this mounting.


In conclusion, our constant force springs are extremely versatile. You may use them across various applications ranging from gym equipment to toys. Due to diverse mounting possibilities, substantial flexibility is possible. It allows for varied load capacity based on your application.

At YongSheng, we design, produce, and mount constant force springs for you, Contact us for more details.