How to draw ellipse
An ellipse may be defined by two foci and Two Radii (minor radius and major radius).
The distance between the focii plus the minor radius gives the ellipse its major
radius, whereas the sum of the major radius and the minor radius gives the ellipse
its maximum width.
Suppose you were to draw an ellipse whose foci are 6 units apart and the maximum
width of 10 inch length
Step 1) On the coordinate system of the marking surface mark the foci (f’,f) and
the width (w’,w). (Fig. 1.)
Step 2) Extend the slide ruler so the thread eyelets coincide with the two foci
(F’,F).
Step 3) Hook a marker into the thread ring and extend the thread on the left side
to a distance equal to the minor radius.
Step 4) Lock the thread using the thread lock
Step 5) Start marking on the surface while keeping the thread taut.
Step 6) Keep marking until the marker reaches the right most end.
Step 7) Flip over the Thread Ruler while keeping the marker on the right most spot.
Step 8) Start drawing the lower half of ellipse until the thread reaches the left
most spot and coincides with the starting point (keep the thread tot).
The ellipse is drawn having the foci distance (F’,F) 6 units and the maximum width
(W’,W) 10 units.
Draw Ellipse
Draw Arcs and Circles
Drawing large ellipse
The maximum distance between the foci is limited by the farthest distance you can
stretch the slide ruler, whereas the maximum width is limited by the length of thread.
How to draw Arcs and Circles
The marker holder and the protractor extension make up the compass part in the Thread
Ruler design. (The protractor extension acts as pivot point to which the marker
revolves around.) Suppose you were to draw a circle having radius 8 units.
Step 1) Place marker in the marker holder, extend the slide ruler to 8 units (measuring
between the pivot point and the marker tip) and press the marker tight.
Step 2) Place the pivot point on the center of the radius while holding the Thread
Ruler from the protractor side.
Step 3) Start marking the surface by moving the ruler around the pivot point.
A circle is drawn after one complete revolution.
Draw Angles
How to draw Angles
The protractor part of the Thread Ruler measures angles between 0 and 90 degrees.
Suppose you were to draw a 30 degree angle extended on line AB.
Step 1) Place the ruler along the line AB where the protractor meets the point A.
Step 2) Measure 30 degree point of the protractor and mark the point C.
Step 3) Draw a line along AC
The angle CAB measures 30 degree.
The protractor measures only up to 90 degrees that would draw angles within the
first quadrant. Larger angles may be drawn by first computing which quadrant the
angle would lie. The first quadrant angles are 0 to 90 degree, second quadrant between
90 to 180 degree, the third quadrant between 180 and 270 degrees and the fourth
quadrant between 270 and 360 degrees.
How to draw parallel lines
You can draw parallel lines using the vertical ruler.
Suppose you were to draw parallel lines between the points A and B.
Step 1) Place the main ruler along the points A and B where the vertical ruler meets
the point A and draw a line along the vertical ruler.
Step 2) Slide the vertical ruler till it reaches the point B. Draw a line along
the vertical ruler.
The two lines are parallel
Draw Parallel Lines
