"Set" height calculation
"Set" height calculation
(OP)
I am very new to spring design and need some help with what I hope is a simple calculation. I have a spring that takes a shorter height “set” after application (I believe it is being bottomed to solid height and cannot prevent this from happening in the application) and need to be able to calculate this shorter height at the design stage (before I have samples). Can anyone help?
Thanks in advance.
Thanks in advance.





RE: "Set" height calculation
I real life the spring maker makes test samples longer than the desired spring and bottoms them to find the free length needed before bottoming that will give the desired spring properties after bottoming.
Anyway, designing for a spring bottoming during application is a bad idea. With each bottoming the spring enters the plastic zone and the spring will have a very!!! short life cycle. If the spring is designed to stay bottomed for long periods it will become even shorter due to relaxation.
Taking your words that you are new to spring design and my experience I am pretty sure that a spring that will not bottom can be found. However, more information regarding forces, deflections, maximum solid length, maximum outside diameter/minimum inside diameter, type of application (static/cyclic/impact), environment, etc., is needed.
http://israelkk.googlepages.com/home
RE: "Set" height calculation
Jack
RE: "Set" height calculation
It is common for a spring manufacturer to coil/wind the spring longer than the final intent, compress it (cold or hot) to remove the set, and the final result will be the spring that meets the length, force, etc. requirements. Even springs that bottom out during impact loading can be successfully designed to achieve > 100,000 cycles before failure, but it requires high quality raw materials, shot peening, etc.
RE: "Set" height calculation
J. Alton Cox
www.delucatest.com