AutoCad 2010 Beginner Help

[nkini]

 

Hello everyone,

 

I am trying to figure out how do I create this arc which does not have centre point co-ordinates . Also not able to use any of the arc or circle features to create this highlighted arc.

 

Any help is greatly appreciated.

 

Thanks.

[amir khan]

Here is the correct dimension picture u can see it

[Tiger]

I would use FILLET probably.

[nkini]

Thanks amir and Tiger. With the corrected picture and radius 10, fillet option would be best.

 

The picture I had with Radius 15 was a bit hard to do.

[DANIEL]

Thanks amir and Tiger. With the corrected picture and radius 10, fillet option would be best.

 

The picture I had with Radius 15 was a bit hard to do.

 

It's because you needed more information, either the center of the radius or the length of that one straight section .....

 

[nkini]

Yes Daniel. Totally agree with you. Thanks for clarifying my doubts.

[JD Mather]

Here is the correct dimension picture u can see it

 

I think you changed the problem. I would not count that correct. Although there is a missing dimension in the original problem - you have changed a given dimension. Can't do that.

 

Oops - I was wrong too. All the needed dimensions are there.

[RobDraw]

Actually all the information is there if you make the assumption that the R15 is tangent to the line extending from the R20.

[JD Mather]

Actually all the information is there if you make the assumption that the R15 is tangent to the line extending from the R20.

 

Yep, you are right.

Solving in a modern parametric CAD program shows that all the needed information is there. (I think it safe to assume tangency.)

 

[DANIEL]

you can make what ever assuptions you want, it doesnt make them right.

[nkini]

 

Assuming tangency, if I were to use manual drafting techniques, I would create a construction line 35 units above centre as shown.

 

With a compass measuring radius 15, I would move along the construction line until it touches point 1 and is a tangent at point 2.

 

But AutoCad has no feature in it to complete this. I am sure it is possible on SolidWorks or other CAD programs.

[JD Mather]

But AutoCad has no feature in it to complete this...

 

Sure it does. At least 2012 does. What release did they include parametric geometry constraints in AutoCAD?

[ReMark]

I believe they first appeared in the 2010 release.

[Dadgad]

I believe they first appeared in the 2010 release.

 

That sounds right to me, they were definitely in by 2011.

[JD Mather]

you can make what ever assuptions you want, it doesnt make them right.

 

In the real world it is often necessary to make educated decisions on the best information available.

 

Is the pilot acting irrationally and should be restrained by the passengers or

is the co-pilot locking the pilot out of the cockpit with some devious plan in mind?

Lives depend on making the correct decision in a totaly unusual and unexpected situation.

 

In the realm of geometry where we are experts - my money (all of it) is on the tangency as the design intent.

Care to take the wager?

[Dadgad]

In the real world it is often necessary to make educated decisions on the best information available.

 

Is the pilot acting irrationally and should be restrained by the passengers or

is the co-pilot locking the pilot out of the cockpit with some devious plan in mind?

Lives depend on making the correct decision in a totaly unusual and unexpected situation.

 

 

 

In the realm of geometry where we are experts - my money (all of it) is on the tangency as the design intent.

Care to take the wager?

 

While the presumption of tangency may seem unsavory, clearly in the absence of any other indication to the contrary, it would appear to be the only logical one.

[SLW210]

you can make what ever assuptions you want, it doesnt make them right.

 

Considering the point was not given in the drawing, then it IS TANGENT, otherwise the point would be given. Same reasoning that you KNOW both sides at 60 are the same.

[DANIEL]

in the real world, here in my office, we would mark it up, stamp it revise and resubmitt and send it back.

[RobDraw]

That was obviously an assignment of some sort for a beginners course not some submittal. It is a challenge for a student with a brain. Draw this part with the given information. It took me less than 2 minutes to figure out that it could be done without using advanced software. Like SLW said, the lack of any other information logically leads you to tangency. Sometimes the obvious answer is the correct one.

 

In industry, you have to spell everything out in order to avoid wrong assumptions such as the one Amir made by changing the radius to 10.

[JD Mather]

... avoid wrong assumptions such as the one Amir made by changing the radius to 10.

 

Ahh, but that dimension was already spelled out on the drawing.

Fortunely the co-pilot on JetBlue was able to make independent decisions yesterday.

The back on 9/11 passengers over Shankseville, Pa were able to.....

 

....comes down to what is the cost and likelyhood of making an incorrect decision based on the information avialable. I guess we should send this one back as the material thickness is not specified either.