Orthgraphic projection help

[dieselixi]

I have a CAD final coming up and my instructor gave us a preview of the the object and we need to do a detailed drawing of the object. I know this seems easy, but i an not sure of what whould be the best position to have the part in when i start my orthgraphic progection. Any help would be much appreciated.

 

 

Preview PDF:

http://www.mediafire.com/?9euweg8czc3ny64

[ReMark]

I would vote for the top view.

[dieselixi]

My only concern was that if its positioned the same way its shown it the top view, it might be dificult to show the hiden features when i do the front view.

[ReMark]

What view would you feel more comfortable starting with? You're the one taking the test not me.

[rkent]

I have a CAD final coming up and my instructor gave us a preview of the the object and we need to do a detailed drawing of the object. I know this seems easy, but i an not sure of what whould be the best position to have the part in when i start my orthgraphic progection. Any help would be much appreciated.

 

 

I think all you need is the top view and then a section. Drawing another ortho projected view will not add to the understanding of the part, especially with a bunch of hidden lines in it. Remember to show the angled arm as though it isn't at an angle in the section.

[JD Mather]

Let us know when you have finished the exam - if I happen to come back this way I'll post my solution.

[dieselixi]

rkent- I think your right, I think the top view and the section view would be the best way to represent the part.

 

Now the other comcern is I've never done a section line through a threaded hole, do I need to somehow show the threads. Also is there anything I need to take into consideration when dimensioning a section view or do I dimension it the same as any other view. Sorry if this all seems very basic.

Edited December 13, 2010 by dieselixi

[JPlanera]

rkent- I think your right, I think the top view and the section view would be the best way to represent the part.

 

Now the other comcern is I've never done a section line through a threaded hole, do I need to somehow show the threads. Also is there anything I need to take into consideration when dimensioning a section view or do I dimension it the same as any other view. Sorry if this all seems very basic.

 

Drawing the threads is not neccessary. An offset line the depth of the root is all you need. You are going to dimension the hole as tapped arent you??? :wink:

[dieselixi]

I'm not sure what you mean by "the depth of the root"

[JPlanera]

OK, as this is an exam i will try to not "give away" the answer. The top view has been established as a given, now the section view will have to pass through both "arms", staying symmetric with respect to the rest of the part. The rest is up to you....

 

Although, and maybe JD can answer this since he is the professor, I would assume your instructor wants to see the "standard" 3 views Top, Front, & Side, even though it can be done with two views, top and section.

 

Also, as rkent said, the orthographic view is purely cosmetic and is not needed

[dieselixi]

Well my teacher always say you only need as manny views as nessasrys to fully reresent the part and all its features. So I can just do a top view, and an aligned section view, But im still having trouble repersenting the threaded hole, on the side of the part. In the top view i can use hiden lines to show the deph and size of the hole, I just dont know how to show the location of the hole in the section view ( the distance from the bottom of the part to the center of the hole) because that feature would be on the other side of the cutting plan.

 

BTW: In my exam we are allowed to use the textbook, notes, ect. I just cant find any information on what i need help with.

 

The picture shows the feature I'm haveing trouble with, I dont know how to show it in the section view. Its circled in red.

 

The blue line is the aligned section line that I plan to use.

Edited December 14, 2010 by dieselixi
Add Picture and notes

[rkent]

You draw the threaded hole with a circle to represent the smaller dia drill that would be used before making the threads. The threads will create a larger circle shown as a circle in a hidden line type.

 

The threaded hole in section would be similar, lines showing the smaller hole, hidden lines showing the threads.

 

Do you have a drafting textbook for this class?

[dieselixi]

I understand that, I just don't know how to show that feature in the section view. I understand how to show it in the top view.

[Jack_O'neill]

The way your section arrows are pointing, you wouldn't see the threaded hole that you have circled in red in a section view. A section line indicates a view as if you had cut the part along the line, then looked at it the direction the arrows point. In other words, if you slice it along the section line, you'd only see what is on the right half of the part. If the arrows pointed to the left, you'd have to show the threaded hole.

 

 

-edit-

 

That is unless it goes all the way through the other side.

Edited December 14, 2010 by Jack_O'neill
afterthought

[dieselixi]

So by switching the direction of the section arrows, i would then be able to show the threaded hole in my section view, assuming that the threaded hole goes all the way through to the center hole of the part itself.

[ReMark]

Does this visual help at all?

 

[JPlanera]

So by switching the direction of the section arrows, i would then be able to show the threaded hole in my section view, assuming that the threaded hole goes all the way through to the center hole of the part itself.

 

Dont confuse yourself. Flipping the section arrows will allow you to represent the distance from the bottom. If in fact the hole does NOT go all the way through, the TOP view will show the depth.

 

Just remember this...

 

Remember to show the angled arm as though it isn't at an angle in the section.

[Jack_O'neill]

Please don't take offense to this comment, but I fear your school is teaching you how to use the software, but not how to actualy draft. If they offer at least a basic drafting class, I very much encourage you to take it. If not, then it would really help you in the workplace to either take a correspondence course or get a self study guide or even an old drafting textbook from the used bookstore and go through it. There is a huge difference between being able to create a part in a cad package and being able then to put that part on paper in a way that is useful to the person who will make that part. It is akin to someone teaching you how to draw pictures with a pencil, but not teaching you to write. Being proficient in the software does not make you a draftsman anymore than being a proficient draftsman will make you a good cad operator. They are two very distinct skill sets that can be used together to create drawings.

 

Take a look at the image below and see if this helps explain how the section view would work, compared to the other views shown.

[Jack_O'neill]

That came out rather hard to see, so here's a pdf that you can actually read.

 

Normally the sectioned surfaces would be hatched, I didn't do that intentionally for clarity. I got in a hurry and did make a couple of small errors on the section view. If nobody points them out i'll post a corrected version with the hatch later.

section line example.pdf

[dieselixi]

Im in the final now, and i gues im allowed to use anY sources i want, including internet : )