In vertical turret lathe work you must often use offset or bent shank cutters

In vertical turret lathe work you must often use

This preview shows page 239 - 242 out of 435 pages.

In vertical turret lathe work, you must often use offset or bent-shank cutters, special sweep tools, and forming tools, particularly when you machine odd-shaped pieces. Many such cutting tools are designed to take advantage of the great flexibility of operation provided in the main head. On a repair ship, you normally will use the vertical turret lathe for jobs other than straight
Image of page 239
28.194 Figure 8-3.—Refacing a valve seat in a vertical turret lathe. production work. For example, you can mount a large valve on the horizontal face of its worktable or chuck easier than on almost any other type of machine. For other examples, figure 8-3 shows a typical valve seat refacing job on a vertical turret lathe; figure 8-4 shows the double tooling principle applied to a machining operation, and figure 8-5 shows a straight boring bar used to bore a large saltwater strainer body. 28.195 Figure 8-4.—Double tooling. 28.461 Figure 8-5.—Straight boring bar being used to bore a large saltwater strainer. TAPER TURNING The following information is based on a Bullard vertical turret lathe. (See fig. 8-1.) There are several ways to cut a taper on a vertical turret lathe. You can cut a 45° taper with either a main turret-held cutter or a side head-held cutter if you engage the vertical and horizontal feeds simultaneously. To cut a taper of less than 30° with a main turret-held tool, set the turret slide for the correct degree of taper and use only the vertical feed for the slide. If you did this operation on an engine lathe, you would use the compound rest and advance the cutter by manual feed. On a vertical lathe, you would USC the vertical power feed. 8-4
Image of page 240
Figure 8-6.—Head setting for 30° to 45° angles. If you swivel the main turret head on a vertical turret lathe, you can cut 30° to 60° angles without special attachments. To machine angles greater than 30° and less than 60° from the vertical, engage both the horizontal feed and the vertical feed simultaneously and swivel the head. Determine the angle to which you swivel the head in the following manner. For angles between 30° and 45°, swivel the head in the direction opposite to the taper angle you are turning, as shown in figure 8-6. The formula to determine the proper angle is A = 90° – 2 B°. A sample problem from figure 8-6 follows: Formula: A = 90° 2 B ° Example: B = 35° Therefore, A = 90° (2 × 35°) A = 90° – 70° Angle: A = 20° For angles between 45° to 60°. swivel the head in the same direction as the taper angle you are turning as shown in figure 8-7. The formula to determine the proper angle is A = 2 – 90°. A sample problem from figure 8-7 follows: Formula: A = 2 B° – 90° Example: B = 56° Therefore, A = (2 × 56°) – 90° A = 112° – 90° Angle: A = 22° When you use the swivel method to turn a taper, use great care to set the slide in a true vertical position after you complete the taper work and before you use the main head for straight cuts. A very small departure from the true vertical will produce a relatively large taper on straight work. You may cut a
Image of page 241
Image of page 242

You've reached the end of your free preview.

Want to read all 435 pages?

  • Spring '16
  • The American, Babbitt, United States Navy, Vernier scale, Caliper, Metalworking measuring instruments, Dimensional instruments

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

Stuck? We have tutors online 24/7 who can help you get unstuck.
A+ icon
Ask Expert Tutors You can ask You can ask You can ask (will expire )
Answers in as fast as 15 minutes