Jet BD-920N User manual

JET
EQUIPMENT & TOOLS
OPERATOR S MANUAL
BD-920N Belt Drive Bench Lathe
(shown with optional stand)
JET EQUIPMENT & TOOLS, INC.
A WMH Company
www.jettools.com
P.O. BOX 1349
Auburn, WA 98071-1349
e-mail [email protected]
253-351-6000
Fax [phone]
M-321373 2/02

Important Information
1-YEAR
JET offers a one-year limited
LIMITED WARRANTY
warranty on this product
REPLACEMENT PARTS
Replacement parts for this tool are available directly form JET Equipment & Tools.
To place an order, call 1-800-274-6848. Please have the following information ready:
1. Visa, MasterCard, or Discover Card number
2. Expiration date
3. Part number listed within this manual
4. Shipping address other than a Post Office box.
REPLACEMENT PART WARRANTY
JET Equipment & Tools makes every effort to assure that parts meet high quality and durability
standards and warrants to the original retail consumer/purchaser of our parts that each such
part(s) to be free from defects in materials and workmanship for a period of thirty (30) days from
the date of purchase.
PROOF OF PURCHASE
Please retain your dated sales receipt as proof of purchase to validate the warranty period.
LIMITED TOOL AND EQUIPMENT WARRANTY
JET makes every effort to assure that its products meet high quality and durability standards and warrants
to the original retail consumer/purchaser of our products that each product be free from defects in materials
and workmanship as follows: 1 YEAR LIMITED WARRANTY ON THIS JET PRODUCT. Warranty does not
apply to defects due directly or indirectly to misuse, abuse, negligence or accidents, repairs or alterations
outside our facilities or to a lack of maintenance. JET LIMITS ALL IMPLIED WARRANTIES TO THE
PERIOD SPECIFIED ABOVE FROM THE DATE THE PRODUCT WAS PURCHASED AT RETAIL.
EXCEPT AS STATED HEREIN, ANY IMPLIED WARRANTIES OR MECHANTABILITY AND FITNESS ARE
EXCLUDED. SOME STATES DO NOT ALLOW LIMITATIONS ON HOW LONG THE IMPLIED
WARRANTY LASTS, SO THE ABOVE LIMITATION MAY NOT APPLY TO YOU. JET SHALL IN NO
EVENT BE LIABLE FOR DEATH. INJURIES TO PERSONS OR PROPERY OR FOR INCIDENTAL,
CONTINGENT, SPECIAL OR CONSEQUENTIAL DAMAGES ARISING FROM THE USE OF OUR
PRODUCTS. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF INCIDENTAL OR
CONSEQUENTIAL DAMAGES, SO THE ABOVE LIMITATION OR EXCLUSION MAY NOT APPLY TO
YOU. To take advantage of this warranty, the product or part must be returned for examination, postage
prepaid, to an authorized service station designated by our Auburn office. Proof of purchase date and an
explanation of the complaint must accompany the merchandise. If our inspection discloses a defect, JET
will either repair or replace the product or refund the purchase price, if we cannot readily and quickly
provide a repair or replacement, if you are willing to accept such refund, JET will return repaired product or
replacement at JET’S expense, but if it is determined there is no defect, or that the defect resulted from
causes not within the scope of JET's warranty, then the user must bear the cost of storing and returning the
product. This warranty gives you specific legal rights, and you have other rights, which vary, from state to
state.
JET Equipment & Tools • P.O. Box 1349, Auburn, WA 98071-1349 • [phone]

A WARNING
1 Read and understand the entire instruction
manual before operating machine
2. Always wear approved safety glasses/face
shields while using this machine
3. Make certain the machine is properly
grounded
4 Before operating the machine, remove tie,
rings, watches, other jewelry, and roll up
sleeves above the elbows Remove all
loose clothing and confine long hair Do
NOT wear gloves,
5 Keep the floor around the machine clean
and free of scrap material, oil and grease
6 Keep machine guards in place at all times
when the machine is in use If removed for
maintenance purposes, use extreme
caution and replace the guards
immediately
7, Do NOT over reach Maintain a balanced
stance at all times so that you do not fall or
lean against blades or other moving parts
8 Make all machine adjustments or
maintenance with the machine unplugged
from the power source
9 Use the right tool Don't force a tool or
attachment to do a job which it was not
designed for,
10, Replace warning labels if they become
obscured or removed
11, Make certain the motor switch is in the OFF
position before connecting the machine to
the power supply
12, Give your work undivided attention. Looking
around, carrying on a conversation, and
"horse-play’ 1 are careless acts that can
result m serious injury.
13 Keep visitors a safe distance from the work
area
14 Use recommended accessories; improper
accessories may be hazardous
15 Make a habit of checking to see that keys
and adjusting wrenches are removed
before turning on the machine.
16 Never attempt any operation or adjustment if
the procedure is not understood.
17. Keep fingers away from revolving parts and
cutting tools while in operation.
18 Keep belt guard in place and in working
order
19 Never force the cutting action
20 Do not attempt to adjust or remove tools
during operation.
21. Always keep cutters sharp
22. Always use identical replacement parts
when servicing.
23 Failure to comply with all of these warnings
may cause serious injury
22. WARNING: Some dust created by power
sanding, sawing, grinding, drilling and other
construction activities contains chemicals
known to cause cancer, birth defects of other
reproductive harm
Some examples of these chemicals are
• Lead from lead based paint
• crystalline silica from bricks and cement
and other masonry products, and
• arsenic and chromium from chemically-
treated lumber.
23. Your risk from those exposures varies,
depending on how often you do this type of
work. To reduce your exposure to these
chemicals: work in a well ventilated area,
and work with approved safety equipment,
such as those dust masks that are specifically
designed to filter out microscopic particles
1

Table of Contents
Warnings.1
Table of Contents.2
Specifications.3
Contents of the Shipping Container.3
Set-Up and Preparation for Operation.3
General Description.4-6
Controls.7
Operation.8-13
Adjustments.14-16
Electrical Connections.16
Lubrication Schedule.17
Parts Lists and Breakdowns.18-41
Wiring Diagram.42
CAUTION
The three jaw chuck and the face plate have a set screw on their flanges that secures them to the
threaded spindle. Before removing the three jaw chuck or the faceplate, remove the set screw
completely from the flange. Failure to remove the set screw may cause damage to the threads on
the spindle. When installing either the three jaw chuck or the faceplate, tighten the set screw
firmly to prevent the chuck or the faceplate from coming off the spindle during operation.
The specifications in this manual are given as general information and are not binding. JET
Equipment and Tools reserves the right to effect, at any time and without prior notice, changes or
alterations to parts, fittings, and accessory equipment deemed necessary for any reason whatsoever.
2

Specifications:
Stock No.
Capacities:
Swing Over Bed.
Swing Over Cross Slide.
Distance Between Centers.
Headstock:
Hole Through Spindle.
Spindle Nose.
Taper in Spindle Nose.
Spindle Bearing Type.
Number of Spindle Speeds
Range of Spindle Speeds.
Gear Box:
Number of Longitudinal Feeds
Range of Longitudinal Feeds..
Number of Inch Threads.
Range of Inch Threads.
Number of Metric Threads.
Range of Metric Threads.
Leadscrew.
BD-920N Compound and Carriage:
.321373 Toolpost Type.Single and 4-Way
Maximum Tool Size.1/2" x 1/2"
.9" Maximum Compound Slide Travel.1-7/8"
.5-5/16" Maximum Cross Slide Travel.5"
.20" Maximum Carriage Travel.16"
Tailstock:
.25/32" Tailstock Spindle Travel.1-9/16"
1-1/2" x 8 T.P I. Diameter of Tailstock Spindle.1-1/16"
.MT-3 Taper in Tailstock Spindle.MT-2
Tapered Roller Miscellaneous:
.6 Steady Rest Capacity.1/4"'-1-1/8"
.130-2000 RPM Follow Rest Capacity.1/4"-1-7/8"
Length of Bed.32"
.27 Width of Bed.4-1/2"
.005"- 011" Height of Bed.6-5/8"
.27 Overall Dimensions.. 37-1/2"Lx19-3/4"Wx15-3/4"H
.8-56 T P.l Main Motor.3/4 HP, 1 Ph., 115V
.11 Net Weight (approx.).235 lbs.
.05-3 0 mm Shipping Weight (approx.).250 lbs
9/16"x16 T.P.I
Contents of the Shipping Container Toolbox Contents
1 Lathe
1 7" Four-Jaw Independent Chuck
1 4" Three-Jaw Universal Chuck
1 Faceplate
1 Four Way Tool Post
1 Operator's Manual
1 Warranty Card
1 Steady Rest
1 Follow Rest
1 Single Tool Holder
3 Chuck Jaws
2 Chuck Keys
1 #1 Cross Point Screwdriver
1 #1 Flat Blade Screwdriver
1 5 pcs Hex Wrench Set
1 8/10mm Open End Wrench
1 MT-2 Center
1 MT-3 Center
1 28T Gear
1 30T Gear
1 36T Gear
1 42T Gear
1 45T Gear
1 80T Gear
Set Up and Preparation for Operation
To avoid twisting the bed, make sure the location to which the lathe is bolted is absolutely flat and
level. Place a machinist’s level on the bedways and check for level side to side and front to rear
If stand mounted, the stand must be fastened to the floor.
Remove rust protected from all surfaces with kerosene, diesel oil, or a mild solvent. Do not use
gasoline, paint thinner, or lacquer thinner These will damage painted surfaces. After cleaning,
wipe with a clean, dry cloth and cover all machined surfaces with a light film or machine oil.
3

General Description
Lathe Bed
The lathe bed is made of high grade iron. By combining
high cheeks with strong cross ribs, a bed of low vibration
and rigidity is produced (Fig. 1) The two precision-
ground V-slideways, re-enforced by heat hardening and
grinding, are and accurate guide for the carriage and
tailstock. The main motor is mounted to the rear of the
bed. (Fig. 2)
Headstock
The headstock is cast from high grade, low vibration cast
iron It is bolted to the bed with four screws and uses
four adjusting screws for alignment. In the head, the
large main spindle is mounted on two precision taper
roller bearings. The hollow spindle is a Morse taper No
3 with a 25/32" bore. (Fig 3)
A quick change of the belt can be accomplished by
easing the tension on the idler (Fig 4)
To protect the machine against accidental damage, a
clutch is fitted to the reduction pulley at the 130 R.P.M
speed.

Carriage
The carriage is made from high quality cast iron. The
sliding parts are smooth ground. (Fig. 5) They fit the V
on the bed without play. The lower sliding parts can be
easily and simply adjusted. The cross slide is mounted
on the carriage and moves on a dove tailed slide. Play in
the cross slide may be adjusted with the gibs.
Move the cross slide with it's conveniently positioned
handwheel. There is a graduated collar on the
handwheel. One graduated mark equals 0.0254
millimeters or 0.001 inches. (Fig. 6)
The top slide, mounted on the cross slide, can be rotated
360°. The top slide and the cross slide travel in dove
tailed slides and have gibs, adjustable nuts, and
graduated collars.
A four way tool post is fitted on the top slide. The four
way tool post can be converted to a single tool holder
with parts enclosed in the tool box. (Fig. 6)
For accurate facing operations, the carriage can be
locked by tightening the hex socket cap screw.
(A, Fig. 7) '
Apron
The apron is mounted on the bed. A half nut is fitted to
the apron. The half nut gibs can be adjusted from the
outside.
The half nut is engaged by the half nut lever. A rack,
mounted on the bed, and a pinion operated by
handwheel on the carriage allow for quick travel of the
apron. (Fig. 8)
5
Fig. 8

Tailstock
The tailstock slides on a V way and can be clamped at
any location. (Fig 9) The tailstock has a heavy duty
spindle with a Morse taper No. 2 socket and a graduated
scale. The spindle can be clamped at any location with a
clamping lever. The spindle is moved with a handwheel
at the end of the tailstock.
Leadscrew
The leadscrew is mounted on the front of the machine
bed. It is connected to the gear box at the left for
automatic feed and is supported by bearing on both
ends. The nut and set screw on the right end are
designed to take up play on the leadscrew. (Fig. 10)
Gear Box
The gear box is made from high quality cast iron and is
mounted on the left side of the machine bed
(Fig. 11) The motor drives through nine changeable
speeds. Always raise idler to the disengaged position
when changing speeds. (A, Fig. 12)
Drive and Electrical Equipment
The main drive is provided by a single phase, A.C. motor
mounted on the rear of the lathe bed. (B, Fig. 12) The
forward-reverse switch (C, Fig. 12) is mounted on the top
of the electric box. The motor condenser is also
contained in this box.
6
Fig. 9
Fig. 10
Fig. 12

Controls
1. Forward/Reverse Switch
2. V-Belt Tension Lever
3. Longitudinal Travel Handwheel
4. Half-Nut Lever
5. Cross Slide Handwheel
6. Top Slide Handwheel
7. Longitudinal Lock Screw
8. Tool Post
9 Tailstock Spindle Handwheel
10. Tailstock Spindle Clamping Lever
11. Tailstock Locking Screw
12. Tailstock Off-Set Adjustment
13. End Gear Cover Lock Screw
14. Automatic Feed Lever
15. Gear Box Quick Change Lever
7

Operation
Tool Set-Up
The cutting angle is correct when the cutting edge is in
line with the center axis of the work piece. The correct
height of the tool can be achieved by comparing the tool
point with the point of the center mounted in the tailstock.
The correct tool height can be obtained by using shims
under the tool. (Fig. 13)
When turning, the tool has a tendency to bend under
pressure. For best results, tool overhang should be kept
to a minimum of 3/8" or less.
Manual Turning
Apron travel, cross travel, and top slide handwheels can
be operated for longitudinal or cross feeding. (Fig. 14)
Fig. 14
Longitudinal Turning with Auto-Feed
Three automatic feeds are available. (Fast = 0.011 "/rev.,
medium = 0.007"/rev., slow = 0.005"/rev.) These can be
set by altering the gear wheel combinations (See table -
Fig. 15)
By moving lever (A, Fig. 16) upward, the automatic feed
is engaged.
% ■
-fK 4 0
a-J ^ 8 0
120-J 40
b-. r 1 27
Lever
9
1 9 1
a
28 28
45 45
b
60 60
60
60
Feed
.005 .007
.007
.011
Fig.15
8