why did he enter 70 instead of 40?

[kingston123]

In this video, @1:58 he entered 70 instead of 40. Why so?

Desired Diagram:View attachment 2081.

 

[MrCATIA]

Maybe it was a typo? Maybe he wanted to change the design?

 

[MrCATIA]

Sorry, it took me a while to see the link to the video.

When he was sketching the L-shaped profile, he wanted the top leg to extend all the way to be tangent with the upper cone.

The distance to the center of the cone is 40mm. The radius at the base of the cone is 60mm/2. So, the length of the top leg is 40 + 30 = 70.

(at 4:15 he adds the R30 fillets)

 

[kingston123]

How can you tell base of the cone is 60/2?

60 is the width of the L shape?

 

[MrCATIA]

That's correct. The width of the L-shaped extrusion (60mm) is the same as the base diameter of the cone.

 

[kingston123]

How can you tell width of the L-shaped extrusion (60mm) is the same as the base diameter of the cone?

 

[MrCATIA]

1. Because of the picture. The line is tangent to the curve, indicating that both are the same width at the tangent point. If they were not the same size, the line would continue past the curve (larger width), or the base of the cone would overlap the line (larger cone base).

2. There is no dimension that says the cone is a different size at the base.

3. If you have the original picture, there should be a Section A-A view that will also show the base of the cone is at the length of the top leg. A top view would be clearer, if it exists.

 

[kingston123]

If you have the original picture, there should be a Section A-A view that will also show the base of the cone is at the length of the top leg. A top view would be clearer, if it exists.

What is the meaning of "section A-A view"?

A top view would be clearer, if it exists.

Yes I agree with you. Top view would clarify my doubt easily.

 

[MrCATIA]

Kingston, you need to take some classes! Blueprint Reading and Basic Drafting would help you tremendously!

you asked: What is a Section View?

Please read the chapter on this link: https://ocw.mit.edu/courses/mechani...d-resources/drawing_and_sketching/#Sectioning

And scroll down to learn more about Cross-Sectional Views