# Flag Day and SOLIDWORKS

With Flag Day and the 4th of July just around the corner, I thought “what great timing to use SOLIDWORKS to create a drawing of the US flag”.

This project required some research on the flag and its proportions.  I never considered all of the work that goes into keeping  the flag proportional when making different sizes until now. This was a perfect scenario to use SOLIDWORKS and equations to keep everything properly in line.

Here is some information about the different variables for constructing the flag:

The basic design of the current flag is specified by 4 U.S.C. § 1; 4 U.S.C. § 2 outlines the addition of new stars to represent new states. The specification gives the following values:

• Hoist (height) of the flag: A = 1.0
• Fly (width) of the flag: B = 1.9
• Hoist (height) of the canton (“union”): C = 0.5385 (A × 7/13, spanning seven stripes)
• Fly (width) of the canton: D = 0.76 (B × 2/5, two-fifths of the flag width)
• E = F = 0.0538 (C/10, One-tenth of the height of the canton)
• G = H = 0.0633 (D/12, One twelfth of the width of the canton)
• Diameter of star: K = 0.0616 (L × 4/5, four-fifths of the stripe width, the calculation only gives 0.0616 if L is first rounded to 0.077)
• Width of stripe: L = 0.0769 (A/13, One thirteenth of the flag height)

I started with a simple SOLIDWORKS layout sketch where the length was 1.9 times the height.  From there I moved to the canton (blue section in the top left corner).  The height of the stripes and size of the stars were next.

Construction lines between the stripes with equal relationships  keeps them all the same size.  Other dimensions required equations to keep the sizes correct.  I renamed the dimension names to make them match the flag image above and used global variables to make the spacing for the stars equal.

The Split line command works to separate the face of the flag into two sections.

Then a few more times to separate the stripes and stars too.

For the rest of the stars using a linear pattern of the star split line and skipping alternating instances of the stars not needed worked out great. It seemed easier to color the entire face of the canton white and then after all of the patterning was done to color the one main face back blue.

Here is a finished version of the flag:

Now it’s your turn to create your very own United States flag in honor of Flag Day.  If you would like a copy of this model in a SOLIDWORKS 2015 format, you can download it here.

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