In this case, some curves related to cycloid are also drawn for further know-how of th reader.
INTERIOR – TROCHOID
If the rectangular lies within the generating circle, the curve traced is called an interior trochoid.
Q.A circular disc of 40 diameter rolls along a st. line for one revolution clock-wise. Draw the locus of a point, which lies at a distance of 12 mm from the centre of the disc.
SOLUTION:
CONSTRUCTION: The following steps are useful to draw Epi-trochoid.
1. Draw a circle with radius [r] 20 mm, and centre as ‘O’ representing the disc and locate the generating point P on the vertical diameter such that Op 12 mm.
2. Draw another circle with centre ‘O’ and radius as 12 mm.
3. Draw a line AB horizontally such that the length of the line is equal to the circumference of the generating circle ‘l.e., 2ur length]
4. Divide the 12 mm radius circle and the line AB into equal number of parts [let us consider 12 equal parts).
5. Through the locus of the centre of the generating circle, draw a line ‘OC’ parallel to
and equal to AB. 6. Draw the perpendicular lines from 1’2′, etc., to meet the line OC at 01, 02,
etc.
7. Draw the lines parallel to AB through the points 1, 2, 3, etc., of the circle R 12.
8. With centre O₁ and radius equal to 12 mm, draw an arc intersecting the line through 1 at P1.
9. In the same way mark the points P2, P3, P4, points 2, 3, 4,… etc. etc., on the lines passing through the
10. The smooth curve which is drawn through these points gives the required interior trochoid.
