KULLIYYAH OF ENGINEERING
DEPARTMENT OF MANUFACTURING & MATERIALS
WORKSHOP TECHNOLOGY
MME 1103
6.1 INTRODUCTION
Milling is a machining operation in which a workpart is fed past a rotating cylindrical rotating tool with multiple cutting edges. The axis of rotation of the cutting tool is perpendicular to the direction of feed. This orientation between the tool axis and the feed direction is one feature that distinguishes milling from drilling. The cutting tool in milling is called milling cutter and the edges are called teeth. The machine tool that traditionally performs this operation is a milling machine. Figure below shows some of the application of milling.
Figure 6.1: Parts and products machined by milling machine
There are two basic cutting operations in milling which are peripheral milling and face milling as shown in Fig. 6.2. The tool axis in peripheral milling is parallel to the surface being machine while the axis of the cutter is perpendicular to the machined surface in face milling.
Several types of peripheral milling are (a) slab milling, the cutter width extend the width of the workpiece on both sides. (b) slot milling, creating a slot in the workpiece, (c) side
milling, the cutter machine the side of the workpiece, (d) straddle milling, similar to side
milling but on both sides, (e) slit milling, the cutter separate the workpiece and (f) form, milling, a special cutter to form the workpiece to desired shape (Fig. 6.3). In peripheral milling there are two opposite directions of rotation that the cutter can have with respect to the work. These cutter direction distinguish two form of milling which are up milling and down milling as shown in Fig 6.4
Figure 6.3: Types of peripheral milling (a) slab, (b) slot, (c) side (d) straddle (e) slit and (f) form
Figure 6.4: Up and down milling
Operations in face milling includes (a) conventional face milling, the tool cutter is bigger than the workpiece, (b) partial face milling, the cutter overhangs the work at one side, (c)
end millng, the cutter diameter is less than the workpiece where slots cutting can be done,
(d) profile milling, a form of end milling of which the outside periphery of the flat surface, (e) pocket milling, another form of end milling which remove the material to
form shallow surfaces (f) surface contouring, using ball nose cutter cutting across a curvilinear path to create three dimensional form.
Figure 6.5: Types of face milling (a) conventional face (b) partial face (c) end (d) profile (e) pocket and (f) surface contour.
6.2 Types of milling machines
Milling machines can be classified into general and production type. In Engineering Workshop there are two types of machines available which are horizontal and vertical milling machine. As shown in Fig. 6.6 is the types of milling machines. In Fig. 6.7 shows the important parts of a vertical and horizontal milling machines.
6.3 Cutting Tools and Cutter holders
Several types of cutting tools and cutter holders available depends on the applications. Fig 6.8 shows the varieties of cutting tools and it’s holders.
6.4 MILLING 1
Procedure
1) Prepare aluminum solid square 80mm x 50mm x 25mm workpiece. (see Fig. 6.9)
Figure 6.9: Milling workpiece
2) Machine the side surface (shaded) by 0.5mm each for a depth of 2mm as shown in Fig. 6.10
Figure 6.10: Face mill surface A to remove 2 mm of material
3) Machine surface B (shaded) by 0.5mm each for a depth of 2mm. (see Fig. 6.11)
Figure 6.11: Face mill 2 mm to reduce the height from 25 to 23 mm
4) Machine other side of surface A by 0.5mm each until the width is 45mm. (see Fig. 6.12)
Figure 6.12: Material to be removed using face milling cutter
5) Machine surface C (shaded) by 0.5mm each for a depth of 2mm. as shown in figure below
Figure 6.14: Material to be removed using face milling cutter
6) Lastly machine the other side of surface C (shaded) surface by 0.5 each until the length is 75mm. (see Fig. 6.15)
Figure 6.15: Last step for milling 1
25
25
6.5 MILLING 2
Procedure
1) Do the marking on the workpiece with the right equipment. The equipments are as follows;
a. Height gauge vernier caliper b. “L” block
c. ceramic table
2) Use “2 flute endmill cutter” of size ø 18mm to bore a blind hole with depth of 10mm. 3) Use “2 flute endmill cutter” of size ø 15mm to mill both end sides of the workpiece
Questions
1. Sketch the milling machine and label the important parts. 2. Name the tool holder and cutting tools used.
3. List 4 operations can be performed using vertical milling machine. 4. Sketch (top, front, side and isometric)of the end product referring to the
procedures.
REFERENCES
1. Groover M.P., (1996), Fundamentals of Modern Manufacturing, Materials,
Processes and Systems, International Editions, Prentice Hall.
2. Gupta J.K. (1996), Basic Workshop Practice, S. Chand & Company Ltd.
3. Kalpakian, S & Schmid, S.R. (2001), Manufacturing Engineering and
Technology – 3rd International Edition, Prentice Hall International.
4. Kalpakian, S & Schmid, S.R. (2001), Manufacturing Engineering and
Technology - 4th International Edition, Prentice Hall International.
5. Kibble R.R, Neely J.E, Meyer R.O & White W.T. (2002). Machine Tool
