Asking for Some Designs URL's or Doc for Practice

If you want types of gears go to gear manufacturers web pages such as Davall. The tooth form & geometry is well defined in books like Machinery's Handbook or similar.

You may learn extrusion and create basic volumes. Like how do you extrude spiral or helical gears or sphere.

Mind does not limit possibilities and challenges.

There are videos on YouTube if you search. Example 1, example 2.

NO NO NO , I AM WELL AWARE OF WITH THE TOOLS OF THE SOFTWARE BUT ACTUALLY I WANT TO PRACTICE SOME CUSTOM AND DIFFICULT DESIGNS . SINCE MY FACULTY TEACH ME SOME BASIC DRAWING WHICH IN MY OPINION IS USELESS. I ASKED THEM ABOUT MY PROBLEM BUT THEY TOLD ME THAT I WOULD GET THOSE TYPES OF DESIGNS IN AND ONLY IN INDUSTRIES DESIGN SECTION AND IT IS VERY MUCH DIFFICULT TO GET THEM IN WEB . SO IF YOU HAVE ANY PDF REGARDING DRAWINGS PLEASE MAIL ME .DESIGNS AND DRAWINGS CAN BE OF ANYTHING

You apparently have no imagination. And no patience, nor manners.

If you can't find something to copy, on your own, then design an automobile transmission or differential. Or copy the design of a turbo encabulator. Gear driven muffler bearings with oil ports are also complex.

Wanting someone to send you drawings to copy hardly seems like a good way to improve your skills.

If you can't find something to copy, then look for a new field of study.

http://www.gutenberg.org/files/23319/23319-h/23319-h.htm#CHAPTER_XI

http://www.tomei-p.co.jp/dealing_brands/holinger/pdf/GEARBOX%20MANUAL%20SF%20%20revision%20D.pdf

http://mach.jlu.edu.cn/jxcx/standars/AGMA-ANSI/ANSI-AGMA%202005-D03-Design%20Manual%20for%20Bevel%20Gears.pdf

Hope this helps

GA, You just beat my post with exactly the same advice

The way that I advanced my skills (and I am still learning) is to get a few basic measuring tools like calipers, and scales, and take apart some actual mechanical assemblies and model them. Not only will you get practice modeling the various components and putting them in assemblies, you get to see how other engineers have approached the mechanical design of these devices.

Another place to look is industrial product catalogs. Many on-line catalogs include down-loadable 2d and 3d Cad models. The McMaster Carr web site for example, has Cad models for many of the products that they sell.

Please don't take this the wrong way, but why aren't you being creative?

You have already said that you have been taught the basics of the software, so why don't you take an object and recreate a 3D model of it with the corresponding 2D drawings?

I went to college many years ago to learn the basics of 2D Autocad, I then went away and picked up anything and everything, measured it and created detailed 2D drawings.

In recent years I have gone over to Autodesk Inventor, now I create a 3D model and then the 2D drawings from that model. You have to be imaginative and logical, but you will only learn from trying out new things. If there is something specific you would like to do, like create spirals, then there are many tutorials online to help you.

As I said I don't take this the wrong way I am not getting at you, but just grab something from the real world and create a copy of it in the digital world, you will get so much satisfaction when you get it right.

Steve