23 Replies Latest reply on May 2, 2018 1:56 PM by Tom dunn

    sketching from a 2d blue print.

    Matt Thomas

      Ok, in my class we are following a book by Paul Tran. I had a question on why he chose to draw the part the way he did and my instructor and i seem to think it has something to do with machining the part.

       

      Here is a picture of the part with fully constrained dimensions. It will be revolved around a center line to make a alignment pin.

       

       

      alignment pin drawing.jpg

      Ok, here is what it will look like after the revolve, then i can ask my question.

       

      revolved part.jpg

      So, here is my question. What was the purpose of the 59 degree line???? I could have made this part with a straight line rather than that angled line. If you look in the part through the smaller hole at the bottom, you will see the cone shape that the 59 degree line makes, but it serves no purpose for the function of the part.

       

      So my original guess was that if the part is machined on a lathe, this is where the drill head would have carved out material. I have only had a few months exp with a manual lathe, but this is my only reasoning to why the book says to draw it this way. I do find it important to why i am doing what i am doing in this book haha. if i dont ask questions, then i am just taking pauls word for it..

       

      thanks

        • Re: sketching from a 2d blue print.
          Christopher Culver

          You are correct in my opinion, 59 degrees is a combined angle of 118 degrees which is a very common drill bit angle.

            • Re: sketching from a 2d blue print.
              Matt Thomas

              that was my thinking as well. I saw it in the book, had that idea, and then asked him. He was not entirely sure, but he said it would make sense that that is what is going on.

              If i would have not had a machining class, that would have baffled me for days haha. i LOVE to know exactly what is going on with a part and the design of it. call me crazy but my brain works that way.. maybe thats why i choose engineering as my degree haha

               

              thank you

            • Re: sketching from a 2d blue print.
              Rubén Rodolfo Balderrama

              You can machine everything on a lathe, excep dimension .155 and 59° . You can do that easy by drilling

              This is only reason I think and If it will be at 90 ° you should first drilling it with a drill and then drill it by calisuar.

              First is a cheap option

              Second has some extra cost

              • Re: sketching from a 2d blue print.
                Chris Saller

                Your instructor is probably teaching very basic revolve. You will learn later with experience to use the Hole Wizard instead of Revolve for this hole.

                • Re: sketching from a 2d blue print.
                  Jeremy Feist

                  I agree also - that is the drill point.

                   

                  but I will also say, that this is a silly way to model this part - at the very least he should have used diameter dimensions.in this sketch. better yet would be to leave the hole out of this sketch and put it in with the hole wizard after the revolve.

                  • Re: sketching from a 2d blue print.
                    Kevin Chandler

                    Matt Thomas wrote:

                     

                    Ok, in my class we are following a book by Paul Tran. I had a question on why he chose to draw the part the way he did and my instructor and i seem to think it has something to do with machining the part.

                     

                    Here is a picture of the part with fully constrained dimensions. It will be revolved around a center line to make a alignment pin.

                     

                     

                    alignment pin drawing.jpg

                    Ok, here is what it will look like after the revolve, then i can ask my question.

                     

                    revolved part.jpg

                    So, here is my question. What was the purpose of the 59 degree line???? I could have made this part with a straight line rather than that angled line. If you look in the part through the smaller hole at the bottom, you will see the cone shape that the 59 degree line makes, but it serves no purpose for the function of the part.

                     

                    So my original guess was that if the part is machined on a lathe, this is where the drill head would have carved out material. I have only had a few months exp with a manual lathe, but this is my only reasoning to why the book says to draw it this way. I do find it important to why i am doing what i am doing in this book haha. if i dont ask questions, then i am just taking pauls word for it..

                     

                    thanks

                    Hello,

                     

                    There are usually several paths in SolidWorks that effectively lead to the same result, as you can see from the hole wizard discussion above.

                     

                    I would suggest that you concentrate more on the lesson than on the rationale behind the example part used in the lesson.

                    Example parts are just that...examples. And they usually have little to no utility outside of the lesson.

                    The same is true on what the lesson's author was thinking. This is irrelevent.

                    Concentrate on and absorb the lesson instead.

                     

                    Learn SolidWorks' various methods, their terms and their options.

                    And with increasing exposure and practice, you'll be better able to discern which approaches are best for a given situation.

                     

                    Cheers,

                     

                    Kevin

                    • Re: sketching from a 2d blue print.
                      Tom dunn

                      In my opinion the sketch without the 59 degree dimension is undefined. (blue)

                      could have been dimensioned like this as well.