Jet J-720R, Operating Instructions And Parts Manual

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It is recommended that when power feed is not
used, the dial be set to neutral. This minimizes any
wear on power feed mechanism.
Any of the three feed rates are available for
selection using any of the spindle speeds
available. There will be a recommended feed rate
for any drilling or boring operation, and this rate
must be determined by consulting appropriate
machining handbooks or tooling and work piece
suppliers.
8.10 Setting depth of cut using
power feed
There is a mechanism for engaging power feed
and also a “trip” mechanism which can be set to
disengage power feed when a pre-set depth has
been reached.
The feed levers (A, Figure 8-2) are pulled outward
or pushed inward on pivots in the feed lever hub.
When the levers are pushed toward the drill head,
the power feed mechanism is disengaged. When
the feed levers are pulled outward, the power feed
system is engaged. In the power feed position
(outward) the quill and spindle will be driven until
one of the following happens:

Spindle reaches limit of travel and the limit
switches disable power; or

Trip mechanism automatically disen-
gages power feed; or

Drill press operator pushes feed levers
into disengaged position.
To set depth of cut:
Refer to Figure 8-2.
Figure 8-2
1. Rotate feed levers (A) counterclockwise to
lower drill until it just touches work piece.
(Note: C and E will rotate together.) Drill-to-
work piece contact represents zero depth
position. Continue holding feed levers in this
position.
2. Push handle (B) to unlock depth control.
3. Rotate dial (C) until required feed depth on
scale (E) is at zero reference mark (D).
4. Push handle (B) to lock this depth setting.
5. Release feed lever (A) to return spindle to
upper position.
6. Rotate feed levers (A) slightly counter-
clockwise (about 5mm quill descent) to start
spindle.
7. Turn spindle switch to SPDL.FOR.
8. Pull feed levers (A) outward to engage power
feed clutch. The power feed mechanism will
feed drill into work piece at the rate selected
on feed rate dial until selected depth of cut is
complete.
Note: The depth limit for power feed drilling is
4.0 inches (100mm). If deeper holes are
needed, the machining must be done in steps.
IMPORTANT: Power feed is used only for
drilling/boring, not for tapping. A feed rate must be
set (out of neutral position) before power feed can
be engaged.
8.11 Spindle direction and power feed
Spindle rotation direction is managed by the
arm/spindle control lever on right side of drill head.
See Figure 7-1.
Clockwise or "forward" rotation is the direction of
rotation for right-hand tooling – the vast majority of
tooling used in machine operations. Reverse
spindle rotation for left-hand tooling.
Power feed direction is determined by spindle
direction. When spindle is set to its most common
direction (clockwise/forward) the quill and spindle
are driven downward. When spindle direction is set
counterclockwise (reverse), quill and spindle are
driven upward.
8.12 Manual feed: roughing
operations
When the feed levers are pushed toward drill head
the power feed mechanism is disengaged. In this
position, the feed levers can be used to move the
quill and spindle and perform manual drilling or
other machining operations.
8.13 Fine manual feed using power
feed clutch
The fine feed handwheel is located on right side of
drill head (see Figure 7-1) and is used as follows:
1. Set feed rate control knob to N (neutral).
2. Pull feed levers out to engage feed clutch.
3. Turn on drill press, and set arm/spindle control
lever to desired direction.