Make a pattern for moulding(part 2)

Discussion of Tools:

                              6. Divider:

It is one kind of marking tools consisting of two legs and a adjusting nut. We use it for drawing a circle on the surface of the timber.

                                              Figure: Divider

                               7. Steel Scale:

It is one of the most common marking tools. Wooden ruler is not comfortable to measure length. But steel scale is very much helpful to measure length or to draw a line.

                                               Figure: Steel scale

                        8. Tenon Saw:

For doing all small job we use a 10in or 12 in row, it is called tenon saw. The angle between the cutting edge and the surface of the job is 45ᵒ.

                                                Figure: Tenon Saw

                      9 . Working Place or Table:

It is like other table. But the difference here with the normal table is there is a wood or job holder in one side or two side of the table. We fixed the job in the holder and did our work very easily and smoothly.

                                   Figure: Working Table

                    10. Oil Stone:

Oil stone is used to sharp the edge of the chisel.

                                          Figure: Oil Stone

          11. Files:

The main function of a file is its plane or smooths the surface. To make the pattern we used two types of files in wood shop such as rough file and smooth file. Smooth file was used for better finishing.

                        

                                               Figure: Files

Operation:

1.   We got the timber which supplied from the workshop: 6″ × 3′ × 3″.

2.   By using a planer we planned the rough surface of the timber. Then we draw the top view and from view on the timber by using scale, pencil and divider.

3.   We used tenon saw to cut the outer surface of the timber. We also used chisel for cutting outer surface to gat required shape of the pattern.

4.   We used rough file and then smooth the surface of the pattern. And lastly for good finishing we used emery paper.

5.   After finishing these operations we got a nice pattern which is ready for casting.

Discussion:

          Pattern making is one of the most important things in doing casting. The pattern is a model made of suitable material and is used for making the cavity in moulding sand. The design should be as simple as possible to make the pattern. We were careful to make pattern so that the edge of the pattern will not broken down. Casting is very much important in production. Pattern making is the main operation for casting. This experiment will help us in future life for practical purpose.