making edge rounded

is there a command to make the edges in 3d solids become rounded

Yes. The command is called Fillet.

thank you for the input but autocad's reply is: it is stated there that fillet command is not supported, could pls somebody help !

Why are you using Mesh for simple geometry?

Convert to solids.

....whick begs the second question, "Why are you learning AutoCAD for mechanical design rather than a next-generation 3D MCAD program like Autodesk Inventor?

Students can download Inventor for free from http://www.autodesk.com/edcommunity

Here is pic of stapler I did in Inventor

sir, the stapler is very beautiful, I can also do that in 3dmax the same, but it lacks dimensioning for production, can that inventor be importable in autocad so to be as plan? like front view, top view,

side view, etc. Maybe there will be steep learning curve in inventor

.. can also do that in 3dmax the

3DMax is for pretty pictures - not product design.

Inventor is far easier to learn than AutoCAD, but AutoCAD is capable of the design you did, you simply need to use the solids tools in AutoCAD.

I agree with JD Mather, just convert your meshes to solids and aply the fillet tool!

We usually use AutoCAD 3D for all of our modeling. We import to 3ds for materials and rendering.

You can generate drawings from inventor.