Technical Drawing 3, WASSCE (SC), 2017

Question 5

 

Fig. 3 shows the component parts of a rocker arm.  The rocker arm R fits on to the body K and held in position by bolt and nut.
Draw full size and in first angle projection the following:

  1.     sectional front elevation on plane P – P;
  2.     left end elevation;
  3.     plan.

Observation

 

This question require candidates to assemble the component parts and then draw sectional front elevation on plane P-P; left end elevation and plan. 

Very few candidates attempted this question and their performance was okay.  However, some of the candidates who did not understand the drawing reproduced the question as given.

Candidates were expected to do the following:

 

THE SECTIONAL FRONT ELEVATION ON PLANE P – P

  1. draw full size;
  2. draw one centre line;
  3. draw the outline of the assembly;
  4. draw the bracket ‘K’;
  5. draw the bracket ‘R’;
  6. draw the bolt;
  7. draw bolt head;
  8. draw the washers – 2;
  9. draw the nut;
  10. draw webs;
  11. section the bracket – K;
  12. section the bracket – R;
  13. write sectional front elevation;
  14. draw neatly.

                                          
THE LEFT END ELEVATION

  1. draw full size;
  2. draw centre lines – 2;
  3. draw the outline of the assembly;
  4. draw the bracket – K;
  5. draw the bracket – R;
  6. draw webs – 2;
  7. draw bolt head;
  8. draw the washers – 2;
  9. draw the nut;
  10. write left end elevation;
  11. draw neatly.

 

THE PLAN

  1. draw full size;
  2. draw centre lines – 2;
  3. draw the outline of the assembly;
  4. draw the bracket – K;
  5. draw the bracket – R;
  6. draw webs;
  7. draw the washers;
  8. draw bolt head;
  9. draw the cutting plane;
  10. draw neatly.

 

The solution is shown below