Tool Posts
What
are the common
tool post designs
used to hold lathe tools on the compound slide
and what are their merits?
There
are four common tool designs:
•
Rocker Tool Post,
Figure 7–21, holds a single cutting tool. Tool
height is adjusted by rocking its curved base wedge in a concave hemispherical base
and locking the tool in place with its top screw. The disadvantage of this post
design is the need to readjust tool height each time the tool is changed. When
doing work requiring multiple tool changes, a lot of time is lost making height
checks and adjustments. This type post is usually furnished when the lathe is
delivered. Some operators invert the concave base and shim the tool to obtain
additional rigidity for carbide tools when making heavy cuts.
•
Open-sided Heavy-duty Tool Post,
Figure 7–22, also holds a single tool. Tool
height is changed by adjusting the rocker or inserting shims underneath the
tool. This design is rigid and excellent for the heaviest cuts, particularly
with carbide tool bits. This type of tool post requires checking and shimming
the tool height with each tool change.
•
Four-sided Tool Post,
Figure 7–23, also called a
turret post
,
holds one tool in each of four sides. Tools are locked in place with set screws
on the top of the tool holder. Any one of its four tools may be used without resetting
tool height. Like the open-sided heavy-duty post, shims may be needed to set
proper tool height when a tool is changed. This design is convenient for
production work since it reduces tool change time.
•
Quick-change Tool Post System
, Figure 7–24, offers the advantage of needing to
set tool height just once for each tool in its holder because the tool height
setting is preserved by its height-adjusting screw. These great time savers are
easy to use and are common in industry.
Copyright © 2004
Metal Arts Press