ROHM ZG/ZS, ZGU/ZSU, EG/ES - Geared scroll chucks - Manual (Page 16)

3.1 Mounting the chuck lathe on lathe spindles with short taper
(table 1)
3.1.1 Carefully clean the taper seat and contact surface of the
chuck and the machine spindle. Check the spindle nose
for radial run-out and axial slip (0.005 mm permitted by
DIN 6386 and ISO 3089)
3.1.2 Mount the chuck on the machine spindle and lightly tigh-
ten the fastening elements.
3.1.3 Check the gap by means of a feeler gauge.
Tightening
a) Chucks moun-
Front-mounted Front-mounted
ted with studs to chucks held on the chucks held on the
DIN 55027 and outer bolt circle to inner bolt circle to
55022 or camlock DIN 55026, 55021 DIN 55026, ASA
studs to DIN 55029 ASA B 5.9 A1/A2 B 5.9 A1/B1
and ASA B 5.9 D1
(not shown)
3.1.4 Firmly tighten the fastening elements to an even torque
in diagonally opposite pairs.
Both the short taper and the face of the chuck must
be in full contact with the spindle nose after moun-
ting.
3.1.5 When mounting the chuck on the lathe spindles with
camlock stud as per DIN 55029 and ASA B 5.9 D1, lock
into place by turning the eccentric bolt to the right.
3.2 Mounting the lathe chuck on lathe spindles with long taper
nose (see table 1)
Before mounting the chuck, carefully clean the taper
hole, screw thread and spindle nose. The taper must
have a snug fit without wobble. Note the key. Tighten the
union nut.
3. Mounting the chuck on the machine spindle head
(valid for all chuck types and face plates)
The specified values apply to a perfectly functioning machine
spindle and correctly fitted lathe chuck. For measurement, use
hardened, precisely centrically ground test mandrels and thick-
walled testing rings (deformation).
If the lathe chuck fails to correspond to the specified permissible
radial run-out deviations, the taper measurements at the ma-
chine spindle must be checked. Check the diameter and pitch
of the short/long taper. At the same time, check the concentricty
of the taper and face play, while checking the face contact for
faults in the case of a short taper.
When testing, the chuck must be closed only at 0-pinion with ar-
row.
4. Checking radial run-out and axial slip in accordance with DIN 6386 part 1 (see table 3)
(only applicable for lathe chucks ZG-ZS, ZGU-ZSU and ZGD)
Adjusting the EG-ES chuck for concentric gripping
The concentric grooves around the face of the chuck
body permit the jaws to be centred approximately by ad-
justing them visually to these grooves.
Chuck a round workpiece or test mandrel with light pres-
sure and use a dial indicator to determine the radial run-
out. Using the small chuck wrench, turn the adjusting
spindle supported in the base jaw to advance or back out
the jaws until the dial indicator ceases to show any devia-
tion. Note that no jaw may be advanced into contact with
the workpiece before the opposite jaws have been bak-
ked out far enough to provide the necessary clearance
to move the workpiece. While the jaws of a centred three-jaw chuck always con-
tact the workpiece, all four jaws with a four-jaw chuck
must be set against the workpiece separately. When
centring a four-jaw chuck, adjust the jaws in opposite
pairs until the workpiece runs true.
On completion of the adjustment, the EG-ES chuck
may only be clamped and unclamped by operating
the pinions recessed into the circumference of the
chuck by means of the large chuck wrench. The adju-
sting spindle may not be used for clamping and unclam-
ping the chuck.
(No mounting screws need to be loosened for this adjustment)
1. Chuck a workpiece or test mandrel and determine the
maximum indicator reading.
2. Depending on the position of the eccentricity, loosen one
or two of the adjusting screw spindles located opposite
the point of the maximum indicator reading.
3. The retighten the remaining one or two screw spindles
until the gripping centre has been corrected by an
amount corresponding to half the indicator reading.
4. Check radial run-out again and repeat the adjusting pro-
cedure if necessary.
5. Lightly retighten the previously loosened adjusting
screw spindles and check again.
Adjusting the chuck for concentric gripping (valid only for chuck ZG Hi-Tru)
Adjusting the EG-ES chuck for gripping unround or irregular workpieces
Using the large chuck wrench, concentrically back out or
advance all jaws to provide sufficient clearance for the
shape of the workpiece to be clamped. Then turn the ad-
justing spindle with the shall chuck wrench to move the
reversible jaws into contact with the workpiece. On completion of this adjustment, the EG-ES chuck
may only be clamped and unclamped by operating
the pinions recessed into the circumference of the
chuck by means of the large wrench.
Reversing the jaws
Attention: For technical reasons the jaw guidings
have to be sharp edged. To avoid injuries safety glo-
ves must be worn when working at freely accessible
jaw guiding edges (i. e. for jaw changing).
Using the large chuck wrench, back out jaws concentri-
cally until the base jaws are approximately flush with the chuck body. Using the small chuck wrench, continue
backing out the jaw until it can be reversed and reinser-
ted. Be sure to observe the proper sequence, procee-
ding from jaw 1 to 4. Finally, remove the reversed jaws
concentrically to the desired position, using the large
chuck wrench.
Chuck
Spindle nose
Spindle nose
Chuck
Chuck
Spindle nose
16