Hardinge 20C Operation manual

INSTRUCTIONS & PARTS LIST B -0009500-0067
20C DEAD-LENGTH®STEP CHUCK
Stop Rod
Spring Retainer
Nut Nut Outer Collet
Stop Body
Belleville Springs (2)
Coil Spring 1-1/8"
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1-1/8"
Stop
Rod
Nut
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D.L. Step Chuck
Stop
Rod
Drive Pin
QUICK START
Quick Start instructions quickly guide
you through the procedure. Read the
main instructions first to thoroughly un-
derstand how to use the product.
•Clean parts & headstock
spindle
•Set face of Stop Rod 1-1/8"
from Stop Body face & secure
•Thread & Secure Stop Rod-
Body Assembly into D.L. Step
Chuck
•Coat Bearing surfaces with
Molybdenum Disulfide grease
•Assemble and secure Spring
Retainer into Outer Collet
•Insert D.L. Step Chuck-Stop
Assembly into Outer Collet
Aligning Pin with slot in Outer
Collet Face
•Slide Belleville Washer
Springs on Stop Rod
•Slide on the Coil Spring &
lock finger tight with the Nut,
fully compressing coil spring,
then back off one full turn
MAIN INSTRUCTIONS
•Clean the Lathe Spindle , Draw
Tube, and the parts of the 20C
Dead-Length Step Chuck
•Set the face of the Stop Rod 1-1/8"
from the face of the Stop Body. Secure with
the 1-1/4" Hex Nut. (This Dimension may
already be set from the factory.)
© Hardinge Inc. 1996
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Outer Collet
• Thread the Spring Retainer into the
Outer Collet and firmly tighten.
will insure maximum life of the mating parts.
angle of the Outer Collet with Molybdenum Disulfide grease (Moly-Lub). This
Step Chuck, the internal bearing diameter and collet head
•Coat the external bearing diameter of the Dead-Length
• Thread the Stop Rod/Body Sub-
Assembly into the Dead-Length
Step Chuck and tighten securely.
• Hold 1-1/4" Hex Nut of theStop Rod Sub- Assem-
bly in a vise and tighten D.L. Step Chuck using a
20C Inner Collet Spanner Wrench and turning clock-wise.
CAUTION: Do Not grip any part of the Step Chuck body in the
vise. The Step Chuck may be permanently distorted or break.
(Hold the Collet with the 20C Collet Wrench [ Part No.
CL-0011759-A] and use a 1-1/4" open end wrench to tighten the
Spring Retainer.)
TOOLS NEEDED
2 ea. 1-1/4 Open End Wrenches
1 ea. 20C Collet Wrench
1 ea. Machinist Vise
1 ea. Moly-Lub Grease
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Nut
Boring Out the Dead-Length
Step Chuck on the Lathe
QUICK START
Boring Out -D.L. Step Chuck
• Insert Dead Length Step Chuck & Stop Sub-Assembly
into the Outer Collet & Spring Retainer Sub-Assembly.
Align the Drive Pin (shown on front page, 1st Figure) in the Step
chuck with the Slot in the face of the Outer Collet.
•Slide the 2 Belleville Spring Washers on the Threaded
Stop Rod with the small end of the first washer towards
the Spring Retainer and the Large end of the second
washer flush with the large end of the first washer, as
Illustrated.
•Slide the compression Coil Spring on to the Stop Rod up
against the Belleville Spring Washer.
•Thread the Hex Nut on the Stop Rod by hand to completely
compress the Coil Spring, then back the Nut off one full turn.
•Place the three 1/8" diameter x 3/4" long
pins in the holes on the face of the Dead-
Length Step Chuck. (A small amount of
grease on each pin will hold them in
place.)
•Activate Closer to Open Position
•Slide the Dead-Length assembly into the
spindle of the machine aligning the
spindle key with the keyway on the Outer
Collet.
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Nut
Coil
Spring
Beleville Springs (2)
Outer Collet & Spring
Retainer Sub-Assembly
Dead Length Step Chuck
& Stop Sub-Assembly
Slot
•Place 3 Pins in face of step
chuck
•With closer in "Open" position,
slide D.L. Step Chuck into
spindle aligning Key
•Adjust Closer until back face of
D.L. Step Chuck just Contacts
spindle face
•Turn Closer 1/2 Turn more &
Continue to next screw hole.
•Tighten Screws in Closer
•Adjust pressure: Low to Moder-
ate force - Approx. 3,000 Lbs.
•Drill, rough bore ,and finish bore
for the workpiece
•Remove & thoroughly clean
•Remount & Adjust Pressure on
the workpiece: Max. 5,000 Lbs.
MAIN INSTRUCTIONS (Continued)
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Pins

Maximum Accuracy and Repeatability:
Bore out to a dimension .001" Greater Than the
O.D. of the workpiece.
Maximum Holding Power:
Bore out to a dimension .001" to
.002" Less Than the O.D. of the
workpiece.
When a stepped type bore is required, finish bore to the
proper size and then face the bottom of the bore to provide a square
shoulder. It is recommended that the corner where the bore and
shoulder meet be undercut to insure that the workpiece fully seats
against the face of the step.
•Using the Illustration as a guide for Maximum Diameters and Depths, Drill, Rough Bore and then Finish Bore the Step
Chuck out to the proper size for the workpiece.
1-1/8"
Stop
Rod
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1/2"-20
TPI
• The Stop Rod is set at a 1-1/8" dimension from the face of the Stop
Body. The Stop Rod can be machined to decrease its length.
Custom Stop Rod Extensions can be made that are threaded into
the 1/2"-20 TPI internal thread in the Stop Rod.
•Remove the Dead-Length Step Chuck Assembly from the spindle and thoroughly clean out chips from the slots
and the bore. Debur the edges of the machined surfaces.
BORING OUT (Continued)
•Draw the assembly into the spindle by adjusting the collet closer draw tube until the back face of the Step
Chuck just contacts the face of the spindle. A very noticeable increase in resistance will be felt at this point.
•Further tighten the draw tube 1/2 turn and then continue turning until the next screw hole lines up.
•Tighten the Screws on the collet closer.
•Make certain that the three 1/8" Diameter pins are fully bottomed in the Dead-Length Step Chuck.
CAUTION: Do not actuate the lathe's collet closer without either the three pins in the face of the Dead-
Length Step Chuck or a workpiece in place. If the unit is closed without the pins or workpiece
in place, both the Dead-Length Step Chuck and the Outer Collet will be permanently distorted
and have to be replaced.
•Close the Step chuck using a low to moderate chucking force, approximately 3000 Lbs.
3-1/2"
1-3/4"
.250
.5
3-1/2"
1-1/8"

All specifications are subject to change without notice.
All marks indicated by ® and ™ are trademarks of Hardinge Brothers, Inc.
Mounting a Machined Dead-Length®Step Chuck in the Lathe
Litho in U.S.A.
April 1996
Form No. B-67A
Part No. BA -0009500-0067
QUICK START
Mounting-D.L. Step Chuck
•Clean Spindle & D.L. Step
Chuck
•Open the Collet Closer
•Slide DL Step Chuck into
spindle aligning Key with Key-
way
•Put the workpiece in the Dead-
Length Step Chuck
•Adjust Closer until back face
of DL Step Chuck just Con-
tacts spindle face
•Turn Closer 1/2 Turn more &
Continue to next screw hole.
•Tighten Screws in Closer
•Do not exceed a chucking
force of 5,000 pounds
•Clean the machine spindle & the Dead-Length Step Chuck.
•Activate Closer to its
"Open" Position.
•Slide the complete assembly into the spindle of the machine aligning the spindle
key with the keyway on the Outer Collet.
•Place a workpiece in the bore of the Dead-Length Step Chuck.
•Draw the assembly into the spindle by adjusting the collet closer draw tube
until the back face of the Step Chuck just contacts the face of the spindle. A
very noticeable increase in resistance will be felt at this point.
•Further tighten the draw tube 1/2 turn and then continue turning until the next
screw hole lines up.
•Tighten the Screws on the collet closer.
•Close the collet closer.
•Adjust the collet closer to the proper closing force. Maximum Recommended
Force: 5,000 pounds.
PARTS LIST
Stop Rod
Spring Retainer
Nut Nut Outer Collet
D.L. Step Chuck
Stop Body
Belleville Springs (2)
Coil Spring 1-1/8"
Pin
Stop
Rod
Drive Pin
Description Hardinge Part Number Quantity
20C Dead-Length Step Chuck Assembly 2041-00-00-000000 1
– Emergency Dead Length Step Chuck 2037-00-00-000000 1
- Pin (Used when machining out the step chuck) 7 731-00-00-000000 3
- Drive Pin 7734-00-00-000000 1
– Nut 1185-00-00-000000 2
– Outer Collet Body 2039-00-00-000000 1
– Spring - Coil 1187-00-00-000000 1
– Spring - Belleville AM-9011700 2
– Spring Retainer 1815-00-00-000000 1
– Stop Body 1813-00-00-000000 1
– Stop Rod 1271-00-00-000000 1
20C Collet Wrench (For holding Outer Collet during assembly) CL-0011759-A 1
20C Inner Collet Spanner Wrench 7897-00-00-0000001 1
Molybdenum Disulfide Grease (Moly-Lub,3 Oz.) VS-10440 1
HARDINGE INC.
One Hardinge Drive, PO Box 1507
Elmira, New York 14902-1507 USA
To Order call: 800-843-8801 • Canada : 800-468-5946 • Phone: [phone] • FAX: [phone]