product disassembly exercise

Today in groups we were tasked to disassemble a Breville mixmaster, note its manufacturing details, and undertake a small case study into how it could be redesigned and optimised for durability / repairability & upgradability / disassembly. The physical construction of the mixmaster was very sturdy,  its die cast aluminium outer shell was very durable and well fitted, its anodised surface finish made it very resistant to scuffing and food spills.


The outer die cast shell housed the inner chasis, the motor and all the interface buttons, inner boss details allowed the shell to fasten to the inner parts. Its disassembly was fairly straight forward, however there were about seven or eight different screws and washers combinations, some had tamper resistant pentaheads, alan heads, philips heads, and flat heads all in different sizes and lengths. The variety of the screw selection greatly increased the disassembly time, it took five people over 55 minutes just to disassemble product (however i think a skilled repairman could do this in a much shorter time).


It is interesting to note that the repair costs in terms of money are often higher than the net construction costs. For example the mixmaster would have come to around $30-40 usd for its manufacturing costs, while it may have taken a skilled repairman 3 hours (3 x $20 = 60) just to disassemble and locate the faulty or damaged part, costs in terms of shipping the replacement part would also have to be factored in. Although the whole point of this exercise is to improve durability / repairability & upgradability / disassembly it is saddening that small fixable faulty parts mean that many appliances are sent for recycling instead of being repaired/serviced and returned back to their owners in working condition. However it is our responsibility as designers to reduce the chance of this wasteful occurrence.

Some possible improvements are:
 - designing the main body around the motor, making it more accessible for repair and upgrade, and reducing the amount of screws that need to be undone to remove it. (it was probably the last inner assembly that was disassembled because it was fastened so many times with different screws)

 - reducing the sheer amount of parts (screws were the main culprit)

 - adding interior clips to the die cast body to reduce the number of screws

 - designing pcb board so that it can be more easily repaired and accessed