ARRAYS, DIMENSIONS AND TOLERANCES

ASSESSMENT QUESTIONS

Question 1

Use the Array command to assist in drawing the spring below.

The following hints may prove helpful.

1. Draw the three horizontal centre lines, and one vertical centre line to provide an intersection that will be the centre of the left-hand loop.

2. Draw a circle to represent the outside of the left-hand end loop, then draw a line at 100° tangential to the top right quadrant of the circle to represent the start of the end loop. Set the angle to 100° using 10° increments in the polar tracking menu and use the Tangent snap to obtain the tangential contact with the circle. Finally, Extend the line to intersect the lower horizontal centre line.

3. Use Offset to generate the wire thickness and wire centre line.

4. Draw a second smaller circle to represent the wire diameter, taking the centre as the intersection of the wire centre line and the outer horizontal centre line.

5. Draw the centre line of the slope of the first coil from the wire circle centre at 80°.

6. Use Offset to draw the sides of the first coil.

7. Draw the wire diameter at the top of the coil.

8. Complete the first coil by extending and trimming lines and circles. You will need to zoom in close to see what you are doing.

9. Use Rectangular Array (or Copy) to copy the coil.

10. Complete the end loop and then draw the construction lines.

11. Mirror the end loop about the horizontal construction line.

12. Mirror the copy about the vertical construction line.

13. Copy this latest version of the loop onto the right end of the spring, but be careful to choose a sensible datum to copy from-to. You could use the intersection of the centre-line of the end coil and the central centre line.

Question 2

Apply dimensions and annotation to the shaft that you drew in Lesson 3. You will have to find out for yourself how to dimension an angle.

Question 3

Draw the bearing shown in the drawing below. Show all dimensions and tolerances.