Installing Gap Bridge; Belt Replacement/Adjustment; Aligning Tailstock To Headstock; Cross Slide Nut Adjustment - Jet GH-1440ZX Operation And Maintenance Instructions

14.5 Installing gap bridge

1. Clean the bottom and the ends of the gap
bridge thoroughly.
2. Set gap bridge in place and align the ends.
3. Loosen the nuts on the locating pins and push
down through the gap into the lathe bed.
4. Replace four hex socket cap screws and
tighten alternately until all are snug.

14.6 Belt replacement/adjustment

1. Disconnect machine from power source.
2. Open end gear cover, remove lower rear cover
and lower side cover. This will expose the
motor and v-belts.
3. Loosen upper hex nut (A, Figure 28). Place
scrap piece of wood under motor to act as
lever. Lift motor up and block temporarily.
4. Remove belts. Install new belts onto pulleys.
5. Lift up on motor and remove temporary
blocking.
6. Tension belts by loosening lower nut (B,
Figure 28) and tightening upper nut (A, Figure
28) until light finger
approximately 3/4" deflection on each belt.
7. Install covers and connect lathe to the power
source.
Figure 28 – Belt adjustment

14.7 Aligning tailstock to headstock

1. Fit a 12" ground steel bar between centers of
the headstock and tailstock (Figure 29).
2. Fit a dial indicator to the top slide and traverse
the center line of the bar.
If adjustment is needed, align the tailstock using
the off-set screws (D, Figure 27) until the tailstock
is aligned.
pressure causes
22
Figure 29 – Tailstock/Headstock alignment

14.8 Cross slide nut adjustment

The cross slide moves via a lead screw which
drives a nut. This can be adjusted if backlash
develops. Backlash is identified by turning the
cross slide handwheel left and right – if there is a
delay before any cross slide movement, the nut
needs adjusting.
Tighten or loosen the two screws shown in Figure
30 until backlash is adjusted out.
Figure 30 – Cross slide nut adjustment

14.9 Shear pin replacement

The lead screw and feed shaft are equipped with
shear pins, which are designed to break in order to
protect the drive system against overload. A
broken shear pin must be replaced.
Knock out the broken pin; line up the holes and
insert new pin.

14.10 Steady rest adjustment

Always lubricate the fingers with grease before
using the steady rest. The point at which the
fingers contact the workpiece require continuous
lubrication to prevent premature wear.
To set the steady rest (see Figure 31):
1. Loosen hex nut (A) to slide steady rest along
the ways.
2. Loosen knurled handle (B) until it can be
pivoted out of the slot.
3. Loosen three lock knobs (C), and back off the
fingers (D) using knurled handles (E).