Bicycle Rack When a full design specification was produced and the weighted objective procedure carried out: Engineering design Assignment, UOB, UK

SCENARIOS 

(a) Bicycle Rack

When a full design specification was produced and the weighted objective procedure carried out, it was found that a tow bar mounted rack was the best solution.

The rack is to bolt to the tow bar once the tow ball is removed. The dimensions of the tow bar bracket are shown in Figure 1. The 330 mm dimension refers to the distance from the ground to the bottom of the bracket. In order to avoid the bikes fouling the car, it should be assumed that no part of either bike should protrude beyond the face of the tow bar bracket (ie between the bracket and the car).

Figure 1

The two bikes to be carried have dimensions shown in Figures 2 and 3. The width of the handlebars of the man’s bike is 420 mm, whilst that of the woman’s is 630 mm. The width across the pedals is 360 mm in both cases.

Your good friend Fred has offered to help build the bike rack and he has access to the following materials and equipment:

• square section steel tubing, 25 mm × 25 mm × 2 mm thick
• steel plate, 8 mm thick
• steel strips, 25 mm wide by 6mm thick
• brazing and welding gear
• a powered hacksaw
• a pillar drill
Design a suitable rack that can be made using Fred’s materials and equipment. It is not necessary to worry about stresses: the materials are capable of exceeding the strength requirements of any design. In addition, the rack should be designed to ‘look right’.

As part of the report, you should produce:

(i) An arrangement drawing showing the outline of the bikes on the rack. This does not need to be very detailed or show any dimensions but should clearly demonstrate that the rack will enable the two bikes to be carried without fouling the car or the ground.

(ii) A detailed engineering drawing of the rack only, comprising front and side elevations with all dimensions required for manufacture shown.

Figure 2 – Man’s Bike

Figure 3 – Woman’s Bike