Advertisement
Mills without power downfeed
– which has no backlash issues – is less laborious, but
remember that the quill is spring-loaded. This calls for
care when releasing the quill locking lever prior to repo-
sitioning the quill downward. If the fine control knob has
been allowed to disengage (backed off counter clock-
wise), the quill will jump up by 0.0" or more. To avoid
this, make sure the fine control is firmly clockwise, lightly
loading the quill rack, before releasing the locking lever.
Figure 3-9 DRO, depth stop & quill locking lever
Mills without power downfeed
PM-940M 0-206 v.indd
(continued)
5
QUILL DOWNFEED
Mills with power downfeed
This is a factory-installed option. Mills shipped without
this option cannot be retrofitted.
Power downfeed, Figure 3-0, can be used to reduce
workload in many routine operations including drill-
ing, reaming, honing, and hole boring with single point
tools.
Three feed rates are available:
0.1 mm
(~ 0.004") per spindle revolution
0.18 mm
(~ 0.007")
0.26 mm
(~ 0.00")
The quill is controlled by hand in two different ways,
coarse and fine. The power downfeed system is de-
scribed later in this section.
In the drilling more, coarse feed, the mill functions like a
standard drill press – pull the rearmost downfeed lever
up and over toward you to rotate the downfeed lever hub
clockwise, lowering the quill. For milling operations the
downfeed levers are right-shifted to engage the down-
feed lever hub with the fine control handwheel, which
may then be rotated clockwise to lower the quill under
precise control.
Coarse feed
For drilling operations swing the downfeed levers to
the left to disengage the lever hub from the fine control
handwheel. Tighten the downfeed lever stop screw to
lock the levers in position, thus preventing unintended
engagement of the power downfeed.
The graduated depth collar can be used to set a depth
stop for drilling as follows:
.
Tighten the Z-axis locks, Figure 3-4.
2.
Lower the quill to bring the point of the drill down to
the desired end point, then tighten the quill locking
lever, Figure 3-0.
3.
Loosen the depth collar clamp lever to free the depth
collar from the lever hub.
4.
Rotate the depth collar clockwise as far as it will go
(it should indicate approximately 5 inches, see Figure
3-). When the depth collar clamp lever is re-tight-
ened, this will define the quill's end stop.
5.
Re-tighten the depth collar clamp lever.
6.
Unlock the quill. While observing the DRO reading,
raise and lower the quill a few times to be sure the
quill stops at the desired end point.
Advertisement
