advice

[Severo]

hi to all I am new and I enrolled to ask you a council, I enrolled in the first year of university in mechanical engineering and an examination of the first quarters is technical industrial design. as matter is really interesting, the theory fascinates me, but the problem is drawing. My exam consists of four written tests, one theory, the other two free-hand sketches of shaft- hub connections and finally the sizing of bearings. I can also pass these four tests with higher grades than 24, the problem is the secoda test, that is the setting of a drawing of particular extrapolated from a set.

during the lessons we did exercises, and drew, then we were assigned tables to be realized, and here comes the problem. on these tables I have a lot of doubts, because while at exercise we were explained the assembling etc.. We were told the mistakes, if I ask the prof anything on the tables assigned at home does not tell me anything, as those tables will be discussion of the oral exam.

I know what cylindrical tolerance, parallelism is for example. game interference..... roughness...filettature....norme etc etc. etc.
but my problem remains the table. the arguments were treated very theoretically and when I find a drawing in front I can not understand what tolerance to put us for example (I saw that we were not told in lesson) and then considering that I attended high school, I never drew are in difficulty. to the prof I can not ask for explanations and insights regarding the tables of the exercises and sincerely I no longer know what to do. In fact asking why I was rejected at the table I went for a boy who never studied.

Now I wanted to ask you there is some good book explaining step by step how to draw, how to do functional analysis, how to put tolerances etc... because otherwise I will be rejected infinity.

Thank you very much in advance.

 

[TECNOMODEL]

books you can find can help you understand how to put on the table properly, respecting norms etc.

the choice of tolerances is another thing. First of all, the "work" must be evaluated which makes the piece you go to draw, so you have to know the operation of the axieme in which it is mounted.

banal example: I have a tree that passes into a hole without particular need. I can make tree without particular tolerances and hole 0.5 bigger.
same tree, but I have to mount a bearing: ok to the hole more 0.5 but the shaft must have adequate tolerances to the assembly of a bearing beyond, probably, to a concentricity with some part of the tree itself on which to stay another piece.

again same tree but must be inserted precise in the hole because it supports: tree and hole will have to have adequate tolerances to eliminate the games and allow mounting.

as you see the cases are very various, difficult to give suggestions.

Perhaps a good text of construction machines would do to your case.

 

[Severo]

thank you so much of the answer you know some good book of this kind because the book I use provides me very theoretical data, I want to draw and make a table I don't say perfect, but almost, it doesn't tell me how to put in the table properly.

What about tolerances etc. What machine construction book do you recommend?

 

[tecnico_plast]

a great book is the turnkey, industrial technical design, vol. 1 and vol. 2.

 

[TECNOMODEL]

a great book is the turnkey, industrial technical design, vol. 1 and vol. 2.

excellent text, but I do not remember if it treats how to choose tolerances.

 

[tecnico_plast]

If I don't remember badly, it is, it also treats tolerances.
Obviously it is not a professional manual, but I think it remains one of the best texts for mechanical design.

 

[Severo]

the chirone is what I already use.

 

[abelli12]

design, design and industrial organization authors: strange consortia
seems like a great book (actually it's 3 volumes) there's practically everything.