Managing arcs and tangents

[Vagulus]

This is the text-book exercise I am working on:

 

Strictly speaking, the back of the jaw consists of two arcs and a tangent. I can't find anything in the book so far that deals with this so I am stuck.

 

Can someone please help me out with a way to do the back of the jaw.

 

Thanks

 

BTW: as to the dimensions, I work in millimetres so I take the given imperial (inch) dimensions, multiply the number by 100, and call it mm.

Hanger_Jaw.ipt

[JD Mather]

You can always sketch a circle and trim.

or

sketch 3-point arcs

or

pro trick - when in the line command if you click hold and drag off off the endpoint of a line - Inventor automatically goes into creating an arc. Very handy, but takes some practice.

 

Example 1 resembles the book. Note that two dimensions are not really needed and shown as (reference) dimensions.

Example 2 is how I would really model the part.

 

Hanger Jaw Example1.ipt

Hanger Jaw Example2.ipt

[JD Mather]

Strictly speaking, the back of the jaw consists of two arcs and a tangent.

 

 

Strictly speaking, the back of the jaw consists of two arcs and 4 tangents.

[Vagulus]

Strictly speaking, the back of the jaw consists of two arcs and 4 tangents.

 

You are right, of course, about the four tangents, accepting that one is tangential to two arcs.

 

 

I figured it could be done, and I see you have done it. What I can't figure out, and what is most use to me, is HOW you did it.

Is there some way to infer this from the details in the Browser?

[JD Mather]

.... What I can't figure out, and what is most use to me, is HOW you did it.

Is there some way to infer this from the details in the Browser?

 

See #14 here

http://www.cadtutor.net/forum/showthread.php?85808-Inventor-101/page2

 

 

[JD Mather]

.... accepting that one is tangential to two arcs.

 

All sketch constraints shown.

 

[Vagulus]

http://www.cadtutor.net/forum/showthread.php?85808-Inventor-101/page2

 

 

 

That's SOME tutorial. I'll spend a few merry hours with that.

Thanks

[Vagulus]

All sketch constraints shown.

 

 

 

Ah Hah! That's a million times quicker than the multiple extrusions I used.

 

 

It's a great insight into the power of the primary sketch. Thanks once more!