Machine Operation - Jet GH-20 ZH Series Operating Instructions Manual

5.5 Starting operation
Before starting the machine check the proper
chucking (see chapter 6.2).
Before starting the machine be sure that the Forward
/OFF / Reverse clutch lever (13, Fig 2) is in neutral
position.
All lever positions must be changed only after the
machine has been stopped.
Turn ON the main power switch (located on the electric
box at the rear of the machine).
You can now start the motor with the main motor
Start/Stop button (16, Fig 2)
Check that the motor is running in the correct direction.
You can now start the spindle rotation with the Forward/
OFF / Reverse clutch lever (13, Fig 2)
Push the Clutch lever
- right and down for forward rotation
-right and up for backward rotation.
Return the lever to its 0-position to stop the spindle
rotation.
The foot break will stop the motor and break down the
spindle rotation.
Attention:
Lathe still has electric power.
The emergency stop button (3, Fig 1) stops all machine
functions.
Turn emergency stop button clockwise to reset.
Note:
The pulley cover (N, Fig 3) and the chuck guard (O) are
limit switch protected. They must be closed to operate
the machine.
5.6 Break in procedure:
To allow time for the gears and bearings to break-in and
run smoothly, do not run the lathe above 560 rpm for the
first 6 hours.
Headstock Clutch:
The headstock clutch is due to wear. To ensure normal
working of the spindle, the clutch must be suitably
adjusted.
- If the clutch is too loose, it outputs low power and is
easy to slip and get hot under load.
- If it is too tight, it becomes difficult to operate and
clutch mechanism will not engage properly.
Also it will loose the overload protect function.
See chapter 8 for clutch adjustment.
Warning:
Do not operate the machine when you notice power
failure due to clutch slipping.

6 Machine Operation

Warning:
Setup work may only be carried out after the
machine is protected against accidental starting.
With pressed emergency stop button.
Levers may be changed only when the machine
has been stopped.
Before starting the machine be sure that the
clutch lever (13, Fig 2) is in neutral position.
When the spindle runs, never turn any handle or
lever. Spindle speeds can be changed only when the
main motor stops. Feed rate can be changed only
when the spindle runs at a low speed or stops.
Before starting the spindle, check if each handle or
lever is at a correct position to ensure normal
engagement of driving gears.
When operating forward/Off/ reverse clutch lever (13,
Fig2), be sure to turn it to the right position. Never
use "pre-position" for cutting at a reduced speed.
Lead screw is used only for threading instead of
longitudinal feeding so that its accuracy can be
maintained and service life prolonged.
In threading, the lead screw drives the apron directly
and the safety clutch of the apron has lost its
protection function. To avoid the machine parts being
damaged, be sure to select suitable cutting depth.
When loading or unloading the workpiece or getting
away from the machine, the operator must stop the
main motor.
6.1 Chucking
Chuck removal:
Before removing the chuck from the spindle, place
board across the bed ways under the chuck.
Support the chuck while turning three cam locks ¼
turn counter-clockwise.
Line up the two marks (A, Fig 6) for removal.
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