how to draw these

[gowtham]

[f700es]

I'd start looking at AutoCAD's 3D surface commands. Start small and work your way up

[BIGAL]

Like f700es I play on the edges with 3d, but if you have never done anything in terms of solids then the chair is very ambitious.

 

Start with extrude, union, subtract, rotate3d, to mention a few commands.

 

There is some tutorials around or look for a book. May get some ebooks now cheap.

[Senile]

If you are new to CAD, the easiest way will be to think of how it will be produced. Just draw your stock material and cut it just like you would in manufacturing. Once you get used to drawing you can often skip the intermediate steps and just draw the final product.

 

On that chair the back and base are the most complicated.  Id probably draw the inner curve of the back from a top view and extrude as a surface, then come in the from the side to create the shape but make this a solid, use intersect to get the inner surface, then thicken to a solid, otherwise the cut won't be perpendicular to the face.

 

It'll also take a while to learn the capabilities of autocad, which are robust but still limited in many critical ways.  To my knowledge there is no way to unroll surfaces or create a sketch on a complex surface.  Honestly I wouldn't mess with the surface, mesh or complex modeling in acad if possible, basically it's bad, solidworks/proe/max/inventor/blender/rhino are all superior depending on your need. (Heck, I'd rather model in MaterCAM  )  

 

If possible look into Rhino, it's cheap, a permanent license, and has way more features.  It also plays nice with other software, they don't strip features out like autodesk has to autocad to try to force you to buy other software (ie: fbx is no longer a supported export type, so now you need max to convert).  So if you are new to AutoCad my advice is to learn Rhino instead, AutoCad is quickly becoming obsolete.  We keep a license, as do all of our vendors, but it is no longer a primary design or manufacturing tool.  We pretty much all run Solidworks/Rhino for design and either MasterCAM or SolidCam to our CNC's.