Taking a cut in a circle

[JD Mather]

my CAD professor tends to have a more communistic approach towards education... so everytime somebody asks her something she doesn't give much help at all

 

Just start modeling with the given information and use Parametric Dimensions and Geometry constraints.

Solve it like you would a crossword puzzle - some of the information is obvious from the drawing - other information will fall in place from the geometry.

[eldon]

could you give me a tip on how to draw this thing?

 

I managed without too much stress and will post the steps tomorrow, but I started with drawing a polygon of 5 sides inscribed in a circle. Then it is a matter of reading the dimensions carefully and see where they apply.

[ReMark]

Looks like your last posted image has a couple of repeating pieces of geometry. Make one of each and array as required.

[eldon]

A few general words first. Draw construction lines to help. They can always be erased or trimmed afterwards.

It is generally easier to draw a complete circle rather than to try and draw arcs. The circles are easily trimed to leave the required arc.

Where a figure has repeated shapes, draw one of the shapes and array those to produce the whole.

 

Here is how I drew it. First draw a vertical line from A about 100 long. Draw a circle diameter 161 at A and trim B to the circle. (You see that I now have a radius line without doing the mental arithmetic of dividing 161 by 2). Now draw a 5 sided pentagon centered on A, inscribed in a circle of radius B. Draw the lines CA and AD. Draw a circle dia 55 on A.

Now draw circles Radius 53 on E, F and G and offset these circles 4 inwards. Draw a line at H and J between the intersection of the outer circles to the intersection of the inner circles. Erase the circles at C and D, and trim the circles at B to the lines H and J, then erase the line at J. You now have left two arcs and a line at H, which will be Polar arrayed later with the inner shape.

Now draw a circle radius 39 at F, and a circle radius 49 at G. Now draw circles radius 5, using the TTR option, at K and L and trim to leave the inner shape.

Now array these shapes to produce the final figure. I will leave the central rectangle and circle to you.

Edited October 24, 2011 by eldon
spotted a typo