I have some problem to create spring in 3D (basically spring wire diameter). i used helix and then sweep command. as per i search. but nothing was happen i need spring in my design.

Hello purti, your commands are OK to have a 3D spring with HELIX and then SWEEP.
With helix you draw the centerline of your spring and then you have to draw a circle of the diameter of your spring wire that you will sweep along the helix.
Press the F2 button  and read the error message that you will get if nothing happens when lauching a command.
Send us a file so that we can take a look at it.
I have AutoCAD Mechanical 2012 and it should be OK.
With that release you can even draw a sping with a non circle wire.
Eventually take a look at my file : 3D SOLIDS 01.dwg that you can find in the CAD Blocks library.
You can also read the CAD Forum Tip N° 836 with direct access here : How to draw a 3D spiral in AutoCADphilippe JOSEPH2014-09-26 07:39:10

There isn't much work involved in creating a spring using the helix command.  First create the helix, next draw a circle, then invoke the SWEEP command.  Pick the circle as the object to sweep and the helix as the path to follow.  Done.What visual style are you using?Did you see any error messages on the command line such as this:Modeling Operation Error:     The sweep results in a self-intersecting body.Unable to sweep 1 selected objects.If so then the diameter of your circle was too large or the spacing of the turns on your helix were too close together thus causing the swept circle to intersect itself which then results in the modeling operation error.
John Connor2014-09-26 14:54:21

An example of a 3D spring created using the HELIX command.  Diameter=2Height=8Turns=20Circle radius=.125