Mechanical Engineering Memories: Assumptions and Designs!

Hi Guys,

After a very long time, I have been quite inactive. This is only the second post I’m writing in October (might extend to November by a few hours when I finish). Life is always interesting. The days I think I’ll be busy, I’m free and the days I think I’ll be free, I get caught up in some work or the other. I had lot of things in my mind to write, but I want to write about a thing I have been thinking of for a long time and that is Assumptions.

Assumptions have become part of my life these days, since we have to reasonably assume in order to solve many of the case studies. But Assumptions have been part of my life even before this. The post is about the Assumptions we had in Mechanical Engineering or in particular Design subjects.

If I remember properly, it started in July 2010 and ended some 10 months later. Two subjects ‘Design of Machine Elements’ and ‘Design of Transmission Systems’. Both the subjects were handled by a single professor, who seemed to be very unfriendly in the beginning and in the end he happened to be a very good guide to many of us.

We had to carry a hefty Design Data Book to the class. Though there was a provision to keep it in the faculty’s desk and take it back, I don’t know why I never preferred it to do it that way. I used to take it back home each day, though it served no purpose other than increasing my bag weight by half kg or so.

There were totally 10 chapters across the two subjects and they had three things in common. 1. Design. 2. Steps and 3. Assumptions. We had to design something like a V Belt, Flat Belt, Shaft, Gear or Gear Box. The questions would be very blunt with lot of data missing. The Design data book is a book that would contain lot of data for various types of situations.

Generally or each question asked, there would be some 10-16 steps. And in most of the steps you would have to make some assumptions. For instance, to design a belt, the diameter would be given, but the material won’t be given. Sometimes, it can be as blunt that the question would be to design a 14 Speed Gearbox. You can take any of the standard dimensions or data from the book. So, actually what happens will be the first decision taken would impact the next decision and so on. The End result would be that everyone in the class would get a different answer and the beauty is that no answer is wrong, if proper assumptions are taken.

It is too difficult to go through each of the assumptions and so as a result, if you know the number of steps to be followed in a problem along with the Formulae (which is quite a trouble, as each step would have a formula and the formulae would be quite lengthy), you will score good marks.

It is actually a very interesting subject which should help a Mechanical Engineer to design the objects he studies in class in an industry. But, sadly our Education system makes it in such a way that the students assumes things in order to get the solution and they never think whether the assumptions would help them in arriving at the final product.

An Interesting subject and nice memories!!!

Happy Reading!!!