Sunday, August 6, 2017

How To Draft A Mariner's Compass Block

I drew this without a compass or a protractor!

I needed a Mariner's Compass style block and I did not want to use/copy an existing block. I didn't want to mess around with geometry and calculate angles and I math. I did it with circle templates and a straight edge, aka ruler. Warning: there are lots of diagrams with lots of steps. 

  Since I am a circle template collector, I started with my set of circle rings.  
(The brown rings are brown because they have a paper backing that I have not removed yet.)
Each ring has 8 marks at N, S, E and W and then in between.  (I don't know how else to describe them.)  I used those marks for drafting.

Starting with the 6" ring, paper and pencil, draw both the inner and outer ring, placing marks where the marks are located on the template.

Draw a line from the mark at the N position to 
Draw a line to include one of the marks, the center and the mark across the circle.  
Do this 4 times.  Number the locations where the line meets the inner circle.

 Draw a line to connect 1 and 4 staying within the inner circle.
Draw a line to connect 2 and 5
Draw a line to connect 3 and 6
Draw a line to connect 4 and 7
Draw a line to connect 5 and 8
Draw a line to connect 6 and 1
Draw a line to connect 7 and 2
Draw a line to connect 8 and 3

Resulting in the first round of points.
Mark the location where the center line of each star point meets the intersection of the star point before and after it. Then label the valley of each star as a through h.)

Now to make the second round of points using the outer circle,

draw a line from the point on the outer circle to the mark to the right and to the left to form the star.
Repeat that 8 times to form the larger star points.
 Erase the pencil marks in the outer star and the lines located in the center.
Using the 3" ring, line it up to connect the marks where the outer stars meet.
To create the center, draw many square in a square rings.  Start by connecting every other mark on the circle to create the first box.  Repeat starting with the next mark and connecting every other.
Continue as many times as desired using the locations where the lines cross.

Draw a 7" square around the medallion

Add another square 1/4" outside the first square.

To create the corner motifs, use the 3" ring template aligning the lines on the template with the inner square.

Draw an inner arc and
extend the line from the short points into the corner.  

Measure 1/2" out from the corner on the inner square and draw a line from the edge to the center of the arc.

Repeat this for all 4 corners.

Trace over each line with a pen or fine tip permanent marker.

This design measures 7 1/2".

How will you use yours?  Stay tuned to see how I will use mine.


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