CAD Challenge

[justacec]

I am having some difficulty in understanding all the necessary dimensions from challenge 2. I have attached it to this message. How do I determine how large the vertical edges are on the ears. It says that the angle is 63 degrees in the between the two angled lines but that leaves an ambiguity. The lower edge is fixed to 19.7mm, however, there is no corresponding constraint on the upper edge?

Screen Shot 2018-06-19 at 6.22.40 AM.png (255.38 KiB) Viewed 2797 times

[PrzemoF]

If there is only one dimension "missing" in a chain of dimensions it's OK. A chain of dimension should no be closed.

Edit: There is more than just one dimension missing as far as I see. You could probably assume symmetry of the "ears" with the holes, but they don't seem to be symmetrical.

[justacec]

@PrzemoF Ahh ok. Thanks for recognizing the issue here. I was hopeful I was just not missing something. I looked at it for quite some time this morning... Incidentally, I notice that there are some measurements in the lower right corner. Do those describe the geometry of the gear teeth? I tried to look it up but did not find a good answer. Since there are no dimensions on the teeth themselves, how do I interpret that?

[A_3]

Another pair of eyes see more.I'll try to fix dimension issue in next few days (or more ).
So, I was editing 50 drawings and I'm glad that someone find errors.
PDF file with drawings is almost ready to be published.

[jona]

@A_3 Is the new version of your document just around the corner ?

[A_3]

If we wait for perfection, we will never do anything. (in this case)
I apologize to all who have been waiting for these drawings for a long time.

The program is developing so fast that some of the things I want to put out are outdated.
Тhere are people who make quality tutorials, in the collection of drawing tasks there's no place for that. I gave up on it, there are only examples to be drawn. Many of the errors have remained, I will solve them, you do not produce the right part anyway, and therefore improvise.
So I'm putting the collections raw version. I still have lot drawings for processing, I hope there will be about a hundred.

Drawings serve for educational purposes only. Have a lot of fun!

Edited g_01.pdf is here!!

[bejant]

Many of the errors have remained, I will solve them

In the second exercise in g_01,pdf, I don't think the keyway should run all the way to the top? It cuts through the outer wall there:

Exercise_g_01-02.png (18.23 KiB) Viewed 1896 times

Exercise_g_01-02.FCStd

(27.36 KiB) Downloaded 66 times

[PrzemoF]

The top view doesn't match the side view. There should be 4 circles, not three. So I guess you have to make the keyway shorter or ignore the 85 mm diameter part.

Edit: I'm open to correction, but there is no need for the angle 30,26 if both lengths and both diameters defining it are given

Edit2: No need for the angle, I'm sure.

Zrzut ekranu z 2019-01-03 13-37-52.png (186.98 KiB) Viewed 1886 times

[bejant]

The top view doesn't match the side view.

I was thinking that the piece is shown in first angle projection so the view on top is showing the bottom, and the 85 mm diameter circle isn't shown (it would be a hidden edge)?

I'm in the U.S. so I'm used to third angle projection...

I omitted that angle, but could have included it in the Sketch as a reference (blue constraint). It looks like your screen grab is from my file?

[PrzemoF]

I'm in the EU No, the screenshot is from the attached file - I did my own version.
OK, so the side view is wrong, because the keyway protrudes through the wall.

Edit: A comment not really relevant to FreeCAD: the part would be probably finished with a lathe, so an angle + one dimension would be better than 2 dimensions. Set the knife at an angle and go as far as required...

P.S. I previously attached _your_ file