Technical Drawing 2, WASSCE (PC), 2016

Question 2

 

In the link mechanism shown above, S, slides along the horizontal JK while the crank ON rotates about the pivot O.  Plot the locus of the point P when the crank ON makes one revolution.


Observation

 

This is a question on link mechanism which requires the candidates to draw the locus of a mechanism as it makes a particular movement. 

            Candidates are required to establish the different positions of the link along with the corresponding positions of crank mechanism.

            Most candidates attempted this question and performed very well.

Candidates were expected to:

 (i)        divide the circle into 8/12 equal parts;
(ii)        indicate different positions of crank ON;
(iii)       draw different positions of link SP to locate different position of point P;
(iv)       join points P into a smooth curve;
(v)        draw neatly.

The  solution is shown below