Design of Automatic Multipurpose Indian Flatbread Maker
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4.2 Grinding Operation
Angle grinders with silicon carbide grinding wheels were used for grinding and
polishing and often for removing excess metal at sections in the dryer that were
otherwise hard to reach or work on.
4.3 Pattern Making
The flattening plates which we have designed according to our need have groove to
place electric G coil heater in it and also keep in account the metal expansion due to
heat. This specially featured component is something which is readily available in
the market in required dimension. So we went for casting of these plates. As known,
pattern making is the first step to casting, and we had to make the replica of our
component. Considering 1% contraction allowance for cast iron, wood pattern was
made with standard surface finish in a 0.025 mm resolution CNC.
4.4 Casting
It took three days to get our 183 mm × 183 mm × 17 mm and 183 mm × 218 mm ×
17 mm (square shape with hinge) plates casted. These plates are casted with gray cast
iron using the pattern. We cannot cast small dimensional features during this process,
and also we know that surface finish of casting is not very good. So machining is
done after casting to achieve desired output.
4.5 Bending
Two sections of 20 mm square pipe were needed to be bend at an angle of 19 degrees
which holds the stationary presser plate for smooth transfer of flattened dough. This
was done in mild steel manual pipe bending machine.
4.6 Drilling
Drilling was performed on the square pipe sections of 675 mm length on the radial
drilling machine. Holes of 10 mm were drilled with intent of using bolts to hold the
pillow bearings to the frame. Four holes of 10 mm were drilled on the metal strip
of 300 mm × 10 mm × 30 mm each. Also, four corners of the cast iron plate each
507
4.2 Grinding Operation
Angle grinders with silicon carbide grinding wheels were used for grinding and
polishing and often for removing excess metal at sections in the dryer that were
otherwise hard to reach or work on.
4.3 Pattern Making
The flattening plates which we have designed according to our need have groove to
place electric G coil heater in it and also keep in account the metal expansion due to
heat. This specially featured component is something which is readily available in
the market in required dimension. So we went for casting of these plates. As known,
pattern making is the first step to casting, and we had to make the replica of our
component. Considering 1% contraction allowance for cast iron, wood pattern was
made with standard surface finish in a 0.025 mm resolution CNC.
4.4 Casting
It took three days to get our 183 mm × 183 mm × 17 mm and 183 mm × 218 mm ×
17 mm (square shape with hinge) plates casted. These plates are casted with gray cast
iron using the pattern. We cannot cast small dimensional features during this process,
and also we know that surface finish of casting is not very good. So machining is
done after casting to achieve desired output.
4.5 Bending
Two sections of 20 mm square pipe were needed to be bend at an angle of 19 degrees
which holds the stationary presser plate for smooth transfer of flattened dough. This
was done in mild steel manual pipe bending machine.
4.6 Drilling
Drilling was performed on the square pipe sections of 675 mm length on the radial
drilling machine. Holes of 10 mm were drilled with intent of using bolts to hold the
pillow bearings to the frame. Four holes of 10 mm were drilled on the metal strip
of 300 mm × 10 mm × 30 mm each. Also, four corners of the cast iron plate each