Determine the Spring Design given Spring Stiffness of 400 N/m

[ftrflyr]

I am trying to design a spring given the following measurements:

Spring Stiffness is 400N/m or 295 ft lbs
Outer Diameter of spring is 0.25 in
Free Length is 3 cm or 1.18 in
Load is max: 5lbs

I am having trouble with:

Calculating the Spring Diamter so as the spring is not over damped or under damped
Ensuring the spring won't buckle
Determining the number of coils necessary knowing the spring stiffness

Any help would be great! Thanks!

 

[SteamKing]

You've got bigger problems than that: k = 400 N/m is not equal to k = 295 lbs / ft.

Why such small springs?

 

[ftrflyr]

Okay disregard the 295 ft lbs then. Small springs because the design is small. :)