MAE 277: Intro to ME Practice Project - Toaster Dissection Report

This project report details the dissection of a 2-slice toaster, conducted as part of an MAE 277 (Intro to ME Practice) course. The assignment required a step-by-step disassembly of the toaster, documenting the tools used and the challenges encountered. The report begins with an introduction to the toaster's components, including the heating elements, bread rack, and various control mechanisms. The dissection process involved removing the casing, screws, and internal components, such as the crumb tray, Nichrome wires, terminal boards, and base. Each step was meticulously documented, specifying the tools used, such as screwdrivers, pliers, and crimping tools. The project also included identifying the required competencies to analyze each component, linking them to relevant mechanical engineering courses (e.g., manufacturing processes, statics, and engineering materials). The report highlights challenges encountered during the disassembly, particularly with the Nichrome wire and ceramic materials. The conclusion emphasizes the importance of detailed design and proper assembly, particularly for the numerous intricate parts within the toaster. The report also references external sources, providing a comprehensive overview of the project.

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Introduction
A mainstay 2 slice toaster refers to that small appliance which is used in heating and hardening
brown bread. Toasters and oven of toasters are usually made from a long list of intricate parts
while includes elements of heating, bread rack, spring, heat sensor, level, trip plate,
electromagnet, timing mechanism, browning control and catch. Majority of these parts are
constructed on the sire while using variety of molded plastics and metals. Nuts, screws, bolts and
washers are used in joining of various parts together. The latest design of the mainstay 2 slice
toaster include wider slots which is basically used for the production of the bagels and bread
slices, plastics which are heated resistant and are used on the body parts and finally controls of
microchip. The process of the construction is usually complex (Brown 2015).
Features of the product
 Stainless steels
 Control buttons
 2 slice toaster
 Browning controls
 Burn warmer
 Removable crumb tray

Figure 1: Parts of the mainstay 2 slice toaster
Tools required for dissecting
 Crumping tools
 Spanner for handling bolts and nuts
 Pliers for unscrewing
Figure 2: Side view of the mainstay 2 slice toaster (Brown 2015)
Dissecting Procedure

i. Toasters are generally made from a pressure molded plastics. The pellets of the plastics
are fed into a hopper before being heated to a high temperature of 350 degrees. The
compound becomes fluid as it heats up. The fluid is then poured into a mold of toaster
case then cooled. After the process of cooling and hardening of the plastic, it is removed
from the mold. This is the case of the mainstay 2 slice toaster. In the case of the
aluminum casing, the casing of the mainstay 2 slice toaster is obtained from a punch
press .The aluminum sheet will have pressure exerted on it by the punch press which has
a die. Dissecting process there started with the analysis of the casing.
ii. The handle is crasp at the toasters side before the removable crump tray is completely
removed out of the unit as indicated in the figure below.
Figure 3: Removal of the crump tray (Brown 2015)
iii. On the machine (mainstay 2 slice toaster) are batches of Nichrome wire. The loading of
the wires on the machine is automatically done hence they are wrapped around the sheet
made from mica. During the dissecting procedure, the wires were un-wound.

iv. It is important to note that during the manufacturing process, the mica sheets were
wrapped with tray which is spring-loaded. These are placed in between the sheets of
mica. The tray is set manually and screwed in place. The process of dissecting will
involve removal of the screws and then disassembling the components manually (Brown
2015).
v. From the whole components, there was a connection of a single bi-metallic element
meant to support bracket. During the manufacturing or assembling process, this element
was mounted onto the second bracket so that it could allow for the motion at a point or
pivoting motion. The dissecting process thus involved removal of the mounted brackets.
This was then followed by the removal of the spring which has been installed between
the two brackets (Willis 2013).
Disassembly of the terminal boards
Prior to the dissecting process, there were two sheet-metal conductors which were rectangular in
shape. They were layered below and above the insulation sheet. As part of the disassembly, the
terminal board had its screws removed so s to disconnect it from the terminal rack. The terminal
end temperature was then detached from a device used for temperature sensing through removal
of screws

Figure 5: Parts of the base
Disassembly of the base
The molded plastic base had its electrical cord threaded into it. During the disassembly
procedure, these components were unthreaded so as to set the base free. Other parts of the toaster
including terminal boards and wire brackets were detached from the base.
Challenges faced
During the process of the disassembly, there was a nick. The disassembly of the toaster using a
high temperature crimp and other tools of crimping was challenging. This was because of the
nichrome wire which is found a round the brittle ceramic material. To some extent there was
suggestion on an attempt to cut this particular component although sawing was much better.

Conclusion
The dissecting procedure though appeared simple; it was changing by being tool-specific for the
operation. Detailed design is usually required so that assemblies are very proper particularly on
the countless parts. The design staff in the manufacturing industry facilities creation of the
prototype during the innovation updates. It is these prototypes which are later subjected to the
battery tests. The mainstay 2 slice toaster has a thermostat which is under the surface temperature
control.

REFERENCES
Brown, Leanne. Good and cheap: Eat well on $4/day. Workman Publishing, 2015.
Willis, Ronald L. "Toaster grill." 2013.U.S. Patent Application No. 14/822,339.