Help for my spring design

[Zirok]

Hi

I have a very simple application which uses a compression spring. There is a slider attached to one end which pushs the spring by 10 mm. After release the spring should throw back a weight of 1 kg(which is the slider weight).

Spring Dimensions -
OD - 14
ID - 9

What should be my -

Closed Length
Free length
Material ...(it should be non corrosive)
Hardness...(should i use a hardened spring. My application is simple but the life is 20-30 years)
Coiling direction...(What should be the coiling direction..Left or right...& what effect it makes on the operation)
Type of end...(There are many types such as plain, ground end. Actually i am going to load the spring on a shaft of 8 mm. As the slider will slider the pin will enter into a hole in the counterpart. This is deliberately done to avoid any extra operation of spring riveting & ensuring failure proof mechanism)

Need Help.

 

[Illmatic1]

Closed Length: This will depend on the length of the spring being compressed. Generally, you should aim for a closed length of at least 50% of the uncompressed length.Free length: This is the length of the spring when it is not compressed. This should be equal to the length of the spring before it is compressed.Material: Depending on the operating environment, you may want to use a corrosion-resistant material such as stainless steel or an alloy such as Inconel.Hardness: For springs that are expected to last 20-30 years, you should consider using a hardened spring material.Coiling direction: Generally, the coiling direction should be chosen based on the forces that will be applied to the spring. If the force will be in the same direction as the coils, a left-hand coil should be used. If the force will be in the opposite direction as the coils, a right-hand coil should be used.Type of end: For your application, you should consider using a ground end. This type of end will provide a more secure connection to the shaft and will be easier to assemble.