Prametric Compression spring

After going through many compression spring models available in different fora, I realized that not much of correct 3D model for a compression spring is available. Most of the models appeared to be good but for the small curvature discontinuity between the first and second turn. I had faced similar challenge in 2008 and I could come up with my own relations to overcome this challenge. I could dig out that old model and posting it here. The parameter "TOTAL_LENGTH" alone is available under Parameters; the rest parameters are available under "RELATIONS". Feel free to play with the parameters to understand the modeling technique used.