Fabrication of different components of the lathe attach- ment, designed earlier is done. Mild steel is the material selected. Strict adherence to the design was ensured when working with appropriate production  processes.

192 J. Inst. Eng. India Ser. C (April–June 2013)   94(2):187–195

Fig. 13  Fabricated tailstock  subassembly

Fig. 14  Fabricated tool post  subassembly

Fig. 12  Fabricated headstock  subassembly

Fabrication is done for the following components of the lathe attachment.

• Headstock subassembly

• Tailstock subassembly

• Base plate

• Tool post

Figure 12 shows the headstock assembly. Here a drill chuck (mounted on a bearing-timing pulley arrangement) and the servomotor (connected to another timing pulley) gives the final assembly of the headstock. Both the timing pulleys are connected by timing belt. Thus chuck rotates with the motion of the  servomotor.

Figure 13 shows the tailstock assembly, a provision is made for the adjustment of height for the tail stock. The end of the tailstock quill is made rotary with the help of bearings. So the tapered portion of the tailstock also rotates with the workpeice. A nut is provided to fix the position of the quill according to the length of the   workpiece.

Base plate contains the headstock assembly and the tailstock assembly. The base plate with complete assembly forms the bed and is mounted on the horizontal Y axis. The base plate is shown in Figs. 12 and 13, on which the headstock assembly and the tailstock assembly are mounted.

Figure 14 shows the tool post, a packing is provided to the tool holder from bottom of the tool post, to prevent it slipping downwards while changing the  tool.

Final Assembly and  Experiments

The base plate (assembled with the headstock and tail- stock) is mounted to the horizontal Y axis. The tool post is mounted to the vertical Z axis of the machine. The cross X axis contains the Y axis, so this axis controls the movement of the bed in the direction of tool, thus the bed is to be moved towards the tool for obtaining desired depth of cut. Longitudinal feed is achieved by the movement of the Y axis. The complete installation of the lathe attachment on the CNC machine can be seen in Figs. 15 and    16.

Following is the specification of the proposed CNC Lathe fabricated.

• Swing over Bed: 15  mm

• Swing over Gap: 30  mm

J. Inst. Eng. India Ser. C (April–June 2013)   94(2):187–195 193

Fig. 15  CNC machine installed with lathe   attachment

Fig. 16  Close view of the lathe   attachment

• Swing over the Cross-Slide: 15  mm

• Range of Centre Distance: 0–120  mm

• Cross-Slide travel: 10 mm

• Tailstock Spindle Travel: 70  mm

• Tailstock Taper: Morse  taper

• Spindle Nose Mounting: 3 jaw adjustable chuck (Drill chuck)

• Spindle Bore Diameter: 13  mm

• Spindle Taper: Morse taper