Accu-Turn 8944 User manual

ACCU TURN
MULTI-SPEED BRAKE LATHE SYSTEM
MODEL 8944
OPERATIONS AND MAINTENANCE MANUAL
PAGE
2 List of Standard Equipment
2 Brake Lathe Specifications
3 Acceptance from Carrier
3 -7 Safety Information
8 Assembly of Lathe
9 -14 Operation Procedures
Multi-Speed Settings
Inspection
Drums or Rotors
Flywheels
15 -18 Diagrams
19 -24 Parts List
25 -30 Additional Diagrams
31 Warranty
When ordering parts contact your local For Records and Information:
Distributor, give Serial # of your machine Date Recv __________
and the date purchased; this will help in Serial # ____________
expediting your order. Rep Name__________
04\97 500
#436311

CONGRATULATIONS ... You have just purchased the finest brake lathe
in the world today. Your ACCU-Turn Lathe is a high quality,
precision engineered product designed to give you years of trouble
free service.
To familiarize yourself with all its features, please take the time
to Read This Owner's Manual Carefully. Store this manual in a safe
place for future reference.
It is important that you Fill Out The Enclosed Warranty Card and
Mail It Back to our Headquarters. This is of primary importance for
authorization of warranty service, for proper parts shipments to
match the model of your machine, and for receiving future product
updates and information.
It is also important that you Record the Model Number, Serial Number
and Other Vital Information Here. These numbers are located on the
back of your lathe.
Dealer _________________________ Purchase Date __________________
Model __________________________ Serial Number __________________

2
STANDARD ACCESSORIES INCLUDED WITH THE 8944 MULTI-SPEED BRAKE LATHE
1 Draw Bar with Hex Nut and Washer
1 T-Bolt with Nut and Washer
1 Spacer Block for Twin Cutter Attachment
2 Large Bell Clamps
2 Small Bell Clamps
3 Centering Cones
3 Silencers
5 Double Taper Radius Adapters
1 Twin Cutter with Tool Holders
1 Boring Bar with Tool Holder
1 Standard 1" Arbor
1 Arbor Nut
1 Arbor Spring
1 1" Spacer
1 Set of Alignment Washers
3 Wrenches 1 1/2", 7/8", 3/8"
8944 MULTI-SPEED BRAKE LATHE SPECIFICATIONS
115 Volt 50-60 --- Hertz 1 Phase 10.0 Amps
Rotor Capacity -------------------------------- 4" to 24"
Maximum width of surface ------------ 4 1/2"
Maximum thickness ------------------- 2 1/4"
Drum Capacity --------------------------------- 6" to 28"
Friction Surface Capacity ----------- 6"
Flywheel Capacity ----------------------------- 6" to 24"
Friction Surface Capacity ----------- 6"
Maximum Weight:
On 1" Arbor ------------------------- 150 lbs.
On 1 7/8" Arbor --------------------- 300 lbs.
Spindle Speed RPM ----------------------------- 100-150-200 RPM

3
Feeds Per Spindle Revolution: (Infinitely Variable)
Disc -------------------------------- .001"-.010"
Drum -------------------------------- .0015"-.015"
Motor ----------------------------------------- 1 Horsepower
Weight:
Net --------------------------------- 474 lbs.
Ship Wt. ---------------------------- 535 lbs.
ACCEPTANCE FROM TRANSPORTATION CARRIER
Carefully inspect all items received in this shipment. If
there is damage or evidence of mishandling in transit, determine
the extent of damage and notify the transit company as well as ACCU
Industries, Inc. immediately. Although we are not responsible for
damage incurred in transit, we will assist in the preparation and
filing of claims.
SAFETY INFORMATION
This manual has been prepared for the operator and those
responsible for the maintenance of the brake lathe. Its purpose,
aside from proper maintenance and operations, is to promote safety
through the use of accepted practice.
READ AND UNDERSTAND THE SAFETY AND OPERATING INSTRUCTIONS
COMPLETELY BEFORE OPERATING THE MACHINE
In order to obtain maximum life expectancy and efficiency from your
brake lathe, follow the operating instructions and maintenance
manual carefully.
The specifications put forth in this manual were in effect at
the time of publication. However, owing to ACCU Industries' policy
of continuous improvement, changes to the specifications may be made
at any time without obligation on the part of ACCU Industries, Inc.
Safety Instructions
1. Read, understand and follow the safety and operating
instructions found in this manual. Know the limitations and
hazards associated with operating the machine. A safety rules

4
decal is installed on the machine to serve as a reminder of
basic safety practice. It should be read before attempting
to use the brake lathe.
2. Special Precautions: This ACCU-Turn brake lathe was designed
to machine the portions of the brake drum, disc brake rotor
and flywheel surfaces that come in contact with the friction
material. When used according to the instructions herein,
this lathe will perform satisfactorily within the workpiece
size range designated for this model.
During the machining operation, the workpiece rotates. Be
especially cautious of rotating wheel lugs, spokes and
mounted accessories. During machining, material removal may
cause a sharp edge to be generated, where a chamfer or radius
previously existed. Use care in handling machined parts.
3. Securing the Machine: The model 8944 weighs approximately 470
pounds and must be bolted to an ACCU-TURN Heavy duty Floor
Stand or a bench capable of supporting the machine, its
accessories and workpiece.
4. Grounding the Machine: In the event of a malfunction or
breakdown, grounding provides a path of least resistance for
electric current to reduce the risk of electric shock. The
lathe is equipped with an electric cord having an equipment-
grounding conductor and a grounding plug. The plug must be
plugged into a matching outlet that is properly installed and
grounded in accordance with all local codes and ordinances.
Do not modify the plug provided. If the plug will not fit the
outlet, have the proper outlet installed by a qualified
electrician.
Improper connection of the equipment-grounding conductor can
result in a risk of electric shock. The conductor with
insulation having an outer surface that is green with or
without yellow stripes is the equipment-grounding conductor.
If repair or replacement of the electric cord or plug is
necessary, do not connect the equipment-grounding conductor to
a live terminal.
Check with a qualified electrician or service personal if the
grounding instructions are not completely understood, or if in
doubt as to whether the lathe is properly grounded.

5
Use only 3-wire extension cords that have 3-prong grounding
plugs and 3-pole receptacles that accept the lathe's plug.
Repair or replace damaged or worn cord immediately.
This lathe is intended for use on a circuit that has an outlet
that looks like the one illustrated in Sketch A in Figure 4.1.
The tool has a grounding plug that looks like the plug
illustrated in Sketch A in Figure 4.1. A temporary adapter,
which looks like the adapter illustrated in Sketches B and C,
may be used to connect this plug to a 2-pole receptacle as
shown in Sketch B if a properly grounded outlet is not
available. The temporary adapter should be used only until a
properly grounded outlet can be installed by a qualified
electrician. The green-colored rigid ear, lug, or other
grounding means. extending from the adapter must be connected
to a permanent ground such as a properly grounded outlet box.
5. Use Proper Extension Cord: Make sure your extension cord is in
good condition. When using an extension cord, be sure to use
one heavy enough to carry the current the lathe will draw. An
undersized cord will cause a drop in line voltage resulting in
a loss of power and overheating. Table 5.1 shows the correct
size to use depending on the cord length. If in doubt, use the
next heavier gage. The smaller the gage number, the heavier
the cord.
6. Eye Safety: Wear an approved safety face shield, goggles,
or safety glasses. (Ordinary eyeglasses are not safety glasses
and do not provide the degree of protection necessary.) If the
operation or area is dusty a face or dust mask should be
used.
7. Personal Protection: Before operating the machine, remove
tie, rings, watches, and other jewelry, and roll up sleeves
above the elbow. Remove all outer loose clothing and confine
long hair. Protective type footwear must be worn. Hearing
protectors must be used where noise exceeds the level of
exposure allowed in Section 1910.95 of the OSHA Regulations.
DO NOT WEAR GLOVES
8. DO NOT OPERATE MACHINE WITHOUT ITS GUARD(S) IN PLACE AND IN
WORKING ORDER.
9. Do Not Use Lathe in Dangerous Environment: Don't use the lathe
in damp or wet locations, or expose the lathe to rain. Keep

6
the work area will lighted.
10. Work Area: Keep the floor around the machine clean and
free of foreign materials. ACC
U Industries recommends the
use of anti-
skid floor strips where the operator normally
stands, and that each m
achine has its own work area marked
off. Make certain that the work area is well-
lighted and
ventilated. Pr
ovide for adequate work space around the
machine. The work area should not be readily accessible to
anyone except the operator.
11. Do Not Overreach: Maintain a balanced stance and keep your
body under control at all times.
12. Hand Safety: Keep hands away from moving parts when the
machine is under power. Never clear chips or debris when
the machine is under power and never use your hands to clear
the chips. Never use compressed air to clean machine; use
only a soft bristle brush or vacuum cleaner.
13. Spindle Rotation: Rotate spindle by hand before applying
power. Be sure that the rotation of the spindle
is correct.
14. Machining Preparation: Tighten all locks before operating the
lathe. Be sure workpiece is secured. Remove adjusting keys
and wrenches. Be sure to check to see that all adjusting
wrenches are removed from the lathe before turning the machine
on.
15. Check Damaged Parts: Before further use of the lathe, a guard
or other part that is damaged should be carefully checked to
determine if it will operate properly and perform its intended
function. Check for alignment of moving parts, binding of
moving parts, breakage of parts, mounting, and any other
conditions that may affect the lathe's operation. A guard or
other part that is damaged should be properly repaired or
replaced.
16. Maintain Tools with Care: Keep tools sharp and clean for best
and safest performance. follow instructions for lubricating
and changing accessories.
17. Avoid Accidental Starting: Make certain that the motor
switch is in the "Off" position before connecting power
to the machine.
18. Never Stand on Lathe: Serious injury could occur if the lathe

7
is tipped or if the cutting tool is unintentionally contacted.
19. Machine Capacity: Do not attempt to use the machine for
other than passenger car and light truck drums, discs and
flywheels, or for operations for which the machine was not
intended.
Grounding
Pin
Grounding
Pin
Grounding
Means
Cover of
Grounded
Outlet Box
Metal Screw
(A)
(B)
(C) (D)
Adapter
Fig. 4.1
Volts Total lenght of cord in feet
Amper Rating 120 V 25 ft. 50 ft. 100 ft. 150 ft.
More Not More
Than Than AWG
12 16 14 12 Not ecommended
Table 5.1

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20. Careless Acts: GIVE THE WORK YOU ARE DOING YOUR UNDIVIDED ATTENTION.
21. Disconnect Electrical Power before performing any service,
maintenance, or changing of accessories, adapters, or workpieces
on machine.
22. Job Completion: If the operator leaves the machine area
for any reason, the machine should be turned off, and the
spindle brought to a complete stop before the operator
departs. In addition, if the operation is complete, the
operator should clean the machine and work area. NEVER CLEAN
THE MACHINE WITH THE POWER ON.
23. Replacement Parts: Use only ACCU-TURN replacement parts
and accessories, risk of injury may result if accessories other
than those recommended are used. USE OF PARTS OTHER THAN ACCU-
TURN PARTS WILL VOID THE WARRANTY.
24. Misuse: Do not use the machine for other than its intended
use. If used for other purposes, ACCU Industries Inc.,
disclaims any expressed or implied warranty, and holds itself
harmless for any injury or loss that may result.

9
ACCU-TURN MULTI-SPEED BRAKE LATHE
OPERATION PROCEDURES
OPERATION
The 8944 Multi-Speed Lathe has multiple spindle speeds and
infinitely variable cross feeds (.001 to .010 per revolution) to
accommodate a wide range of machining tasks. It is important to
remember that the desired surface finish depends on the correct
relationship of the spindle speed with the cross feed speed. As a
general rule, slower spindle speeds require slower cross feed
speeds. Also deeper cuts normally dictate that a slower cross feed
rate and/or spindle speed may be necessary.
Multi-Speed Settings
The 8944 Multi-Speed Brake Lathe has three different pulley
selections.
(1) The small pulley at the motor in conjunction with the large
pulley at the gear box drives the spindle at 100 RPM's. This
speed is recommended on large diameter drums, rotors, and most
flywheels; the cross feed rate should be set at a slow
setting. Position feed rate indicator between "0" and "3".
(2) The middle pulleys rotate the spindle at 150 RPM's and are
normally used to machine intermediate size rotors and drums
that have a larger diameter than most used on passenger cars.
At this spindle RPM, cross feed can be set at a slow to medium
feed rate. Position feed rate indicator between "2" and "5".
(3) The large pulley at the motor and the small pulley at the gear
box allows the spindle to rotate at 200 RPM's. This spindle
speed should be satisfactory for most passenger car drums and
rotors. The cross feed speed may be set at a variety of rates
from slow to fast to produce the desired finish. Position the
feed rate indicator between "3" and "8".
Note: High pitch squeals may occur if cross feed rates are set too
slow. It may be necessary to advance the cross feed rate slowly to
eliminate the noise. If chatter occurs, the cross feed rate should
be adjusted to a slower feed rate.

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ASSEMBLY OF BRAKE LATHE
Setting Up Brake Lathe For Operation
All machined surfaces are covered with a protective coating
before packaging. They must be thoroughly cleaned with solvent.
The spindle, arbor taper and mounting surface on top of ways must be
cleaned and wiped dry.
Install the draw bar in the arbor. Insert the draw bar through
the spindle, and align the match marks on the arbor and spindle.
Install the washer and nut on the rear of the draw bar, and tighten
to 55 foot pounds. Mount the drum boring bar or rotor twin cutter
on the machine; make sure all inserts, bolts, and set screws are
tight.
Machine must be securely fastened to work bench surface before
operating. Four mounting holes on the base are provided for this
purpose.
Lubrication
Lubricate ways by oiling felt wipers on the end of cross slide
every week with SAE 10W oil or equivalent, and check gear box by
removing vented plug on top rear of housing. Oil level should be
about 2 inches from the top. If needed, use MOBIL Synthetic Gear
Oil - SHC 634 (ACCU-Turn #430866). Capacity is one quart. DO NOT
OVER-FILL.
Electrical Information
Standard motors on this machine are wired to 115 volt, 60

11
cycle, single phase. Check electrical input plate on rear of
machine. The Off-On switch is located to the right end of the main
housing. Never operate machine unless power supply agrees with
electrical plate rating and machine is properly grounded.
ACCU-TURN 8944 MULTI-SPEED BRAKE LATHE
MOUNTING AND MACHINING PROCEDURES
Inspection of Brake Drums, Disc Rotors & Flywheels Before
Machining
IMPORTANT: The maximum amount of metal removed from the
finished workpiece should never exceed the manufacturer's
specifications. It is dangerous to operate a vehicle with a drum,
rotor or flywheel which has had more material removed than is
allowed. Proper operation cannot be established if these
specifications have been exceeded. ACCU Industries recommends that
each workpiece be checked for size before mounting on the lathe and
after machining.
Mounting Hubless Drums or Rotors
1.
Clean and check all surfaces for flatness that will come in
contact with centering cones and/or bell clamps
to ensure
solid mounting.
2.
Cleaning and properly mounting the drum or rotor prior to
machining will ensure a minimum of stock removal, better
surface finish and optimum braking efficiency.
3. Excessive run out or wobble of the dr
um or rotor after it has
been properly cleaned and mounted on the arbor may indicate
severe damage to the drum or rotor. These drums or rotors
should not be used for further service.

12
4. a. Select proper size bell clamps and slide one on the arbor.
b. Slide spring on the arbor.
c. Find the centering cone adapter that fits the
center hole of the drum or rotor and slide it on the
arbor.
d. Slide the drum
or rotor on the arbor and then the other
bell clamp.
e. Add necessary spacers (double tapered radius adapters may
be used as spacers), alignment washers (make sure they
are installed concave to convex), hex nut and tighten
securely. Do not jerk or over tighten. (See example on
page 15)
5. WRAP RUBBER SILENCER BAND AROUND DRUM, STARTING WITH THE
PLAIN END AND MAINTAIN TENSION UNTIL THE CLIP IS SECURED. DO
NOT ATTEMPT TO MACHINE DRUMS WITHOUT USING THE SILENCER BAND.
Silencer should be nearest open side of drum. Silencers
should also be used for rotor machining.
6. If arbor appears distorted, check for rust, burrs or chips on
cones, drum or rotor, bell clamps, spacers, arbor or other
mating surfaces.
7. Composite hubless rotors may require optional composite
rotor adapters.
Mounting Hubbed Drums or Rotors
1.
Select the double tapered radius adapter that properly fits
the inside of the large bearing ra
ce. It should sit in the
race similar to a bearing and move side to side in all
directions easily. If it
binds in any direction, this is an
indication of an incorrect adapter selection or a damaged
bearing race. Correct problem before proceeding.
2. Slide the double tapered radius adapter all the way onto
the arbor. If the drum or roto
r contacts the lathe, a spacer
may be required between the double tapered adapter and lathe.
3. Using the same procedur
e as in Step 1, select the double
tapered radius adapter for the outside race.
4. Install the drum or rotor and pos
ition it on the back double
tapered radius adapter and then slide the front double tapered
radius adapter on the arbor and into the front race.

13
5. Use adapters or spacers as necessary to space out to the end
of the arbor. (See example on page 15) Double tapered r
adius
adapters may be used as spacers. Add alignment washers (make
sure they are concave to convex) and hex nut t
hen tighten. Do
not shock load, jerk or over tighten.
6. WRAP RUBBER SILENCER BAND AROUND DRUM, STARTING WITH THE
PLAIN END AND MAINTAIN TENSION UNTIL THE CLIP IS SECURED. DO
NOT ATTEMPT TO MACHINE DRUMS WITHOUT USING THE SILENCER BAND.
Sile
ncer should be nearest open side of drum. Silencers
should also be used for rotor machining.
7. If arbor appears d
istorted, check for dirty or damaged
mounting surfaces and/or adapters. Loosen and re-tighten
arbor nut as described above in Step 5.
Machining Hubless and Hubbed Drums
1. Position the boring bar so that the 45 degree angle tool bit
slot is toward the drum, with the capscrew to the top. BORING
BAR EXTENSION SHOULD BE KEPT TO A MINIMUM. Boring bar must
not be rotated upward or downward.
2. For extra small diameter drums, set the boring bar at an angle
towards the arbor while extending the boring bar outward
from the boring bar holder.
3.
Turn on the machine. Slowly advance the boring bar in the
drum and contact the point of the greatest wear.
4.
Note the reading on the calibrated handwheel; back out one
full turn and move to the rear of the drum.
5. Set handwheel to .005 deeper than the noted reading; this will
ensure a finished drum in one cut.
6. Engage the cross-feed handle for the drum slide with the
ON-OFF switch to drum position.
Machining Hubless and Hubbed Rotors
1. The twin cutter must be positioned in proper alignment with
the rotor. Center the disc rotor between the two tool bar
holders. The tool bars are fed by calibrated knobs at
either sides of the bars.
2. With machine runn
ing, set the tool bars for depth of cut by

14
loosening the locking screw on top of the tool bars so that
the bars will move freely when the calibrated knobs are
turned.
3. Adjust cutter bars to remove the minimum amount required
to finish the rotor in one cut. DO NOT MACHINE A ROTOR TO
LESS THAN MANUFACTURER'S SPECIFICATIONS.
4.
If surface is scored, locate the deepest score and turn the
ro
tor micrometer knob until the tool bit bottoms out at the
deepest point of the score; zero the scale and back out the
tool bit. Repeat on other side. If no score exists, touch
rotor with tool bit near outer edge and advance calibr
ated
hand knob until full circle is scratched on rotor and "O"
knob. Back out the tool bit.
Numbers 5-6 instructions on next page.

19
5. Advance the twin cutter by handwheel until the tool bits
have cleared the inner edge of the rotor face. Adjust the
micrometer knobs for approximately .005 more than the first
reading. This will ensure finishing the rotor in one cut.
Some rotors may require optional "Zero" angle tool holders.
6. Tighten locking screws. IT IS NOT NECES
SARY TO TIGHTEN THESE
SCREWS EXCESSIVELY.
The replacement carbide inserts have three cutting surfaces.
When sufficient wear causes an inferior finish, rotate the
carbide insert to a new tip. There is a precision relief
below the cutting edge. DO NOT TURN THESE INSERTS OVER.
Mounting Flywheels
1.
Clean the machined surfaces, so they are free of rust, dirt
and burrs.
2. Select the centering cone that fits the center hole. Then
select the bell clamps that fit the cones and the
center
machined area of the flywheel (you may use one large and one
small bell clamp).
3. Mount the flywheel in the same manner as a hubless rotor or
drum, with the side to be machined facing the lathe. See
example on page 17.
NOTE: DOWEL PINS OR STUDS MUST BE REMOVED BEFORE MACHINING.
4. Use silencer when possible. Magnet packs or bars may be used
as silencers.
Machining Flywheels
1. Loosen the two square head set screws on the boring bar
holder; remove and insert the reverse end (small flat
surface up). DO NOT TURN THE BAR OVER; ONLY TURN 180
DEGREES, END FOR END IN HOLDER.
2. The left hand edge of the tool bit insert should be at a
90 degree angle to the surface to be machined. Adjust boring
bar to obtain minimum extension.

20
3.
Turn the right calibrated handwheel (drum slide) until carbide
insert makes contact with the lowest point of the flyw
heel;
note the reading.
4. Move to the inside surface and turn the handwheel .003" -
.005" greater that the
noted reading. On flywheels with hard
spots, the minimum depth of cut should be .012".
5. Engage the rotor cross-feed handle on the front cross slide.
6. It is recommended to use the 2" boring bar if available for
flywheels.
CAUTION: When machining cup-type flywheels you must stay with the
lathe, because you must stop the unit and re-position the
tool bar for the outside lip surface. You must also
remove the same amount from the outside mounting surface
as was removed from the lower surface; failure to do
this may cause incorrect clutch operation.
FOR INFORMATION ON SPECIAL APPLICATIONS, CONTACT YOUR
ACCU-TURN DISTRIBUTOR OR CALL ACCU INDUSTRIES AT
[phone]
Sharp Tools Are Vital To Satisfactory Operation
When ordering supplies or replacement parts for this machine,
always give the model # and serial # of the machine. Use only ACCU-
TURN parts.
8944 MULTI-SPEED BRAKE LATHE
PARTS LIST
ITEM # PARTS # QTY. REQ'D. DESCRIPTION
1------------436106-------------1---------HOUSING
2------------434014-------------1---------COVER, HOUSING
3------------434420-------------1---------GASKET .015
4------------420772-------------4---------SCREW

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PROPER MOUNTING OF HUBLESS ROTOR OR DRUM

16
PROPER MOUNTING OF HUBBED ROTOR OR DRUM

17
PROPER MOUNTING OF FLYWHEEL