Help How to Reduce the elasticity

[webmagic]

As my last post, I create a rope in runtime by link some points, it works fine.

http://obi.virtualmethodstudio.com/forum...-3098.html

but when the rope created, it works too good in elasticity... 

I just want to reduce the elasticity, how could I do? 

See the video below, I don't want the box jumping up and down by elasticity, 
actually I want the rope swings from left to right. (like the movie Tarzan)

Video: https://drive.google.com/file/d/1c2R7v19...sp=sharing

I tried reduce the Box Rigidbody Mass  but it becomes worse

Oh...I just want to create a rope like in your example "RopeAndJoints" , hard rope.