Bulova Series 218 User manual

ACCUTRO
Service Manual N
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by BULOVA

1
PATENT NOTICE
The ACCUTRON timepiece is manufactured by Bulova
Walch Company, under issued patents as well as pending
paieni applications, including the Following patent*:
O.S,
Canada
France
GemuuT)
Great Britein
SwiUarlaod
Hale
The %Vfir.-) amis
Japan
Z.MO,5*2i 3,971.3211 l.l82.uoe; j,it4.«P.:Re.
».2S7.7&t; 3.221.190; 3.262.259; 1.411.1 ia -i:i H
:
fi76,*17: &09.081; 7M.17B: 756,0ia; 085,410
1.102,373; 74.002: 70,710: 1,401.131:
1.473.153: 1.122,1*3
S71.0SU: 1.096,747; 1,124.413
TBI.009; 797.051: 84D.DH,- BS4.13G;
953.U9; 1,064.230; 1,074,104
112,299; 333.403; 142.171: 301,311
SI7.879; 5M.3.3; 552.IH52; W1JIB: liw.i::
23.037
SO.tSS; 50.196
249,102, 3U1.4&5; 4fl=.52G: 3*0.MS: 2*«,!«'. ;*ft_31
All information contained herein is based on the latest product information a»aitebie at
the lime of printing. The right is reserved lo make changes at any time without notice.
Capjnprt £lft&6. 1969, Baloa Watch Cosipany, Inc. ail "(his reserved.

Table of Contents
Page
To the Watchmaker 2
Part I-SERVICING PROCEDURES 3
Opening the Case 3
Replacing the Power Cell 4
Regulation 5
ACCUTRON" Regulators 5
How to Regulate 6
Removing Movement from Case 7
Replacing Movement in Case 8
Part II -REPAIR OF THE BASIC MOVEMENT 9
Special Tools and Equipment 9
ACCUTRON Service Kit 9
Cleaning Equipment 11
Rate Recorder II
Diagnostic Chart 12-13
Special Points for the ACCUTRON Repairman 14
Indexing Mechanism—Inspection and Adjustment 15
Testing Power Cell 19
Testing Electronic Circuit 19
Identifying Defective Coil Assembly 20
Checking the Train for Freedom 20
Hack Mechanism—Inspection and Adjustment 20
Disassembly _21
Cleaning 30
Lubrication 31
Reassembly 32
Basic Parts List Series 218 40-41
Part III-REPATR OF DATE MECHANISM IN MODEL 218D 42
Removing Hands, Dial, and Hour Wheel 43
Date Mechanism Disassembly 45
Date Mechanism Lubricatinn and Reassembly _. 45
Replacing Hour Wheel. Dial, and Hands 46
Parts List Model 218D 47
Index 48
'"ACCUTRON," -BUIQVA." "VfATCKKASTBr aid "Li" are registered trademarks of Billow Watch Company, Inc.

To The Watchmaker,
This Manual provides complete service and repair information for Scries 218
ACCUTRON movements. Perhaps ynu already have experience in servicing ihe 214
ACCUTRON. Tor which there is aseparate service manual. If so. you will fad thai
while Ihe repair and servicing procedures for 214 and 21 AACCUTRON movements
are basically Ihe same. there are physical differences between (he two. primarily in
the arrangement of parts.
Unlike the 214 ACCUTRON movemenl, Ihe 218 muvemenlN can be repaired and
adjusted wilhnut Oie use of amicroscope. However, those experienced in servicing
ihr /i-i nOVCjeeat (and therefore having aKiutable microscope nvadable). will find
the iniineicope very useful in checking and adjusting 'he 2111 tmli-xinx mechanism.
Even If you have never tmrvlced ACCUTRON. we would like lo poinl out thai the
experienced watchmaker nhoulil ho able lo learn lo service the 210 ACCUTRON
movemenl iu amatter of hour* wilh Ihe aid of this manual. Diagnostic procedures
Tor locating and correcting faults are presented on pages 12 and 13. The firs! step in
using these procedure is lo estuhlish the symptoms of Ihe trouble. In many in
RtanQM Ihin inforiiiatiun cm he obtained only from the customer. Therefore, WHEN
EVER POSSIBLE KIND OUT EXACTLY WHAT THE CUSTOMER'S PROBLEM IS
BEFORE YOU ATTEMPT CORRECTION,
For example, let us assume that an ACCUTRON timepiece has been bronchi In you
because it is gamin*; or Inning lime. You must find out whether the gain or loos in
nfew seconds aday or aminute or more aweek lo determine whether It requires
only simple regulation or whether the movemenl mufil be repaired. Suppose yon
are told only llml "it loses" and your rate recorder indicates aloss of. say. 5seconds
.i day. If you regulate it accordingly nnd return it, you will have avery dissatisfied
customer if ihe timepiece was losing several minutes per day (requiring repair) On
the odicr hand, the timepiece may have been losing several seconds per day, as
shown by your rale recorder, In this case, if you elect to "repair" ihe movemenl. you
are attempting lo locate adefect or fault Ihat does not exist. Such situations can only
he avoided by finding out from the customer the symptoms Ihat led him to bring
the timepiece lo you for correction.

Opening The Case
Use special Inckmy

r
i
Replacing the 218 Power Cell
a. Remove case back, using a
suitable case wrench to unscrew
the locking-ring.
b. Loosen coil lorm screw slightly.
cLoosen cell strap hold-down
screw, swing cell strap out and
remove Power Cell as shown
(see Fig. 3).
d. Remove coil form screw (with
insulator) and cell strap, Inspect
(with loupe) under-surface of cell
strap for foreign matter which
may affect electrical contact with
Power Cell. If necessary, clean
with an eraser and dip-rinse.
e. With the cell strap off. check thai
the insulating posl of the cull coil
assembly hus not been damajtr. 1
through improper installation Of
aPower Cell; attach cell strap
by loosely installing coil form
screw (with its mutilator] through
cell strap, making certain cell
strap is correctly positioned
.imund the insulating post of the
cell coil assembly.
f. Install the Power Cell with
imprinted side down (see Fig. 3);
reposition cell strap under tbt
hold-down screw and sccurr
screws.
g. Check that case gasket is properly
positioned; replace case back
and tighten locking-ring.
Note: If sweep-second hand does
not turn, be sure stem is
in the normal or "in"
position. If so, tap the case
lightly at "3" or "9" to
start tuning fork vibrating.
COIL FORM SCREW WITH INSULATOR POWER CELL
CELL
SIMP
CELL COIL ASSEMBLY
Fig. a

MAY is4 iboy
Regulation
THE BASIC ACCURACY OF THE ACCUTRON TUNING FORK IS SUCH THAT
REGULATION FOR MORE THAN AFEW SECONDS PER DAY IS NOT REQUIRED.
CAINS OR LOSSES OF AMINUTE OR MORE AWEEK INDICATE THE NEED
FOR REPAIR. NOT REGULATION.
ACCUTRON regulators
The ACCUTRON regulators (see Fig. 4Jare serrated to make them easier la rotate
and to serve asacalibration.
G3SERVE THE SEVEN "DMSKWS
Fig. »
The serrations of each regulator form 7divisions (4 projections and 3indentions).
Each of these divisions is equal to 2seconds per day of correction; in other words,
rotating one of the regulators adistance equal to one division, changes the rate of the
ACCUTRON timepiece by 2seconds per day. Regulation for as little as x /x second per
day can be made byrotating one of the regulators V* division. The amount thai aregu-
lator is rotated can be easily gaged by reference to the dot on the top of each cup.
Either one or both of the regulators can be rotated in making acorrection; for exam-
ple, acorrection of 4seconds per day can be made either by rotating one regulator 2
divisions, or by rotating each of the regulators 1division.
Since there are 7divisions on each of the regulators, and since each division is equal
to 2 seconds per day. it would be impossible to make acorrection of more than 28 sec-
onds per day. even if both regulators were originally set all the way in one direction.

How To Regulate
IS
Rotate one or Imlli of the regulators (see Fir. 5)asufficient number of divisions and
in the direction necessary to make ihe required correction. Rotating aregulator away
from the center of the movement will cause the ACCUTRON timepiece to run slower:
rotating aregulator toward the center of the movement will cause it (o run faster.
mHICULAU ?SECONDS PER DAY SLOWER,
MOVE fUMIK REGULATOR ONE DIVISION
OUTWARD AS SHOWN.
TO REGULATE 2SECONDS PfR DAY TASTER,
MOVE EITHER REGULATOR ONE DIVISION
INWARD AS SHOWN
!
Fig. 5

WAY 24 ;3S3
1
Removing Movement
From Case
a. Pull stem oat [setting position].
b. Loosen setting lever screw
2turns. (See Fig. 6.)
cWithdraw stem.
Fig. 6
a. Remove movement from case
and place in movement holder.
b. Insert stem and tighten
setting lever screw.
CAUTION: Do not push
stem beyond point of
engagement with pin on
selling lever. (See
Special Points, item 2,
page 14.]
Fig. 7
IMPORTANT: S« sore To Indicate model number engraved on movoment whan ordering replacement pans

Replacing Movement In Case
r~

MAY Bt '2Q$
Part II
Repair of the
Be. Movement
Special Tools and Kquipmtrnl
kit
The revised ACCHTKON Serv.ie Kit httu the specinl tools necessary lo perform
<li.r "i i. .-.. |.mm! lo Mrvioe ihr 2lfl ACCUTRON timepiece,
Imi i!m .'III. |he following Imil-. IN mm IihIi-iI
l.TripU^parpOM •],-, (ill |V>.| S.-I (Model GOO)
2. Movement Holder
:i. t.Mikiup-rin); wrvm h
4. Collet Adjusting Tool
In mldilirm. the revised ACCUTRON Service Kit hnn the oilier (rpei Mtools neces-
sary lo service the 214 movement
Note; ir you already own in ACCUTRON Sendee Kit for the ACCUTRON Modal
:'.l lynir i.,m hove it modified tohandli- Ilie ACCUTRON Series 210 »tn well
The Model COO Test Set. illustrated in Fin ID. is ->» BtWrflllftl nnil in servirirn: th-
ACCITKON inovetiii-nl The T-'.l Sel is n-qmred lo perform Lhree very important
I'unrlians-
i. It provide* ahigh reshlinci voltmeter lochecl the ACCOTRON Power Cell, (Con-
ventional lov.-re-.i-.UiKT voltmeters us not suitable Tor thin purpose.)
2. Il is designed to check the currcnl in the rlei.tronu eircuil. In indfealQ III operating
condition. {Conventions! hlgh-rr-sisluno- mirro<niimeiei>. an- mil lettable for this
purpose.)
3. It provides an accurate source for the reduced voltages required for the adjust-
ment of the 214 and the 218 [ndaxiBa, t&QehaaiSffle, (The two voltages are not the
semeO
Note: The Model 600 Test Set is designed for use with both the 218 and the 214
ACCUTRON movements.

-
rtpn
DOOT«l Sol
7WTWI MyroridHt
1. A"nest" to hold «Power Oil during testing. The nest bclearly marked for proper
insertion of either the 214 Power Cell or the 213 Power Cell.
2. Ameter, rending cither volls or ulCrMUBpWVtt todfc*UU| 'he correct values by
areas marked "OK."
3. A-1 position Rotary Swildi lor the selection of the VlrfOUl iMl "'"fliiiutis:
Position i-"t:i n-( ft pi )W1-:k (EH"
Position 2-"OFF"
Position :t "KKAUMICKOAMPKKKS
Position 4- "LOW AMPLITUDE". In this position the Test Set supplier, the
appropriate induced voltage for important Indexing Mechanism Adjustment,
for both the 214 and 2111 movements.
4. A2-wire lend, wilh alab end and aplug end for attachment to the 218 ACCUTRON
movement and movement holder.
5. A2-wire lead, wilh aspring clip for attachment to the 214 ACCUTRON movement.
6. Ablack screw, directly below the center of the movement dial, for zeroing the
meter hand.
movement bolder
The Movement Holder (Fig. 11)is specially designed for the 218 ACCUTRON move-
ment and is used to hold the movement whenever it is removed from the case. The
electrical jock on the Movement Holder is used in accommodate the plug tip end of
the 2-wire lead from the Test Set
Fig. II
10

MAY 24 1969
locking-ring wrench
Awrench, designed for opening (he case, is illustrated in Fig. 12.
Fig. 12
collet adjusting tool
This tool, illustrated mFig. 13. is mod lo adjust the engagement of the index and p.nvl
fingers II is inserted in ihe index finger collet or the pawl finger collet and gentlv
turned to portion 'he index or pawl Jewel with respfr.l 10 tAO Index wfaaol
Fig. i.i
Ultrannnic rquipment is strongly recommended for cleaning the mechanical BtCttOO
of the ACCUTRON mnvrment The IrdtafteStrna] stefl of the 320 teelh on ihr beryl-
liiiiiir.upprr index wheel requires the maximum penetration power available in
Olnuonie cavitation generated by nickel transducers The WATCMMASTER ultra-
sonic Walch Cleaner is recommended.
nit* recorder
The rale of the ACCUTRON tuning fork can be recorded only on equipment spe-
cifically designed for that purpose. Aspecial transistorized amplifier, with suitable
frequency dividers, has been developed by Bulovo engineers lo show this rate.
Tlur. ACCITRON Rale Recorder will also record popular odd heal, spring driven
and electric watches.
Note: For further information on the ACCUTRON Service Kit. Ihe ACCUTRON
Power Cell Tester", the WATCHMASTER Ultrasonic Cleaner or the ACCU-
TRON Rate Recorder, write to
:
Technical Sales ft Services Division
Bulova Walch Company. Inc.
Bnlova Park.
Ftosbing. N. Y. 11370
'Not shown la this pahBaUan
11

HA
GAINING OR

STOPPED
Sweep
second
hand does
not turn
but fork
hums.
"'
1. Crown in setting
rouD position.
2. Power Cell voltage
km.
3. Hack mechanism
out of adjustment
4. Indexing
mechanism out
of adjustment
5. Mechanical inter-
ference with free,
vibrations of fork.
6. Mechanical
blockage
of train.
7. Dirt in tooth of
index wheel.
MAY 24 1369
8. Damaged teeth on
index wheel.
STOPPED

-
Special Points for ihc ACCUTRON Repairmnn
1. Removing or Re-
placing Hands
2. Replacing Slem
The ACCUTRON movement, br-ing completely different from conventional watch
movements, requires different techniques in its repair. Otherwise, it may be damaged
by improper procedures on the part of the repairman. For example, turning the hands
or the gear train fin either direction) with the hack lever disengaged, will damage
the index wheel teeth or the index and pawl fingers The repairman's attention is
called to the following special points:
Always pull crown out [setting position) before touching the hands for any reason.
As with convrnlionul watches, the stem should preferably be pulled "out" [setting
position) before loosening the setting lever screw to remove the stem. In replacing
lhestem.il it in pushed in, beyond 1In- point of engagement with the pin on the setting
lever, the hunk levi-miny btdopEHttd In this bnrtftt tturning the crown will dam-
age the indexing mechanism. For thin reason, do nol push the item in beyond the
point where the stum groove may be engaged by the netting lever pin. before tight-
ening the Betting lever screw.
3. Index Wheel The teeth on the index wheel will not wear away in normal use. nor can they be
damaged as uresult of any accident, when the movemont is enclosed in its caw (with
the crystal inl.iU]. The index wheel can only be damaged by improper handling on
the pad of the repairman. If It is suspected that the teeth on the index wheel have
been damaged, the moat practical solution ts to replace it. since visual examination
will rarely dInduse the damage because of the size of these tiny teeth.
4. Electrical
Contact
5. Circuit
6. Magnetism
7. Magnets
Partially
Demagnetized
8. Adjustment
of Indexing
Mechanism
Make ahabit of cleaning the cell strop, which can be done efficiently with an
eraser, and wiping any while adherent material, if present, from the Power Cell.
Such material may (sometime?] "push" the cell strap away from the Power Cell and
thereby break elect rlcul contact In such instances removing the residue, particularly
on the underside of the cell utrnp will prevent alatent problem in this regard,
i I . ice ul elei i-i. .i| i.-.t equipment in proi rdurcs uthi'i than UMM :.-i mmm-mied.
should be avoided. In p.irin ular. circuit elements can be damaged by the use of an
nhinmeter for testing ihe circuit.
Never demiigiicli/.e an ACCUTRON movement or expose It to high-strength magnetic
fields (permanent magnets, lor example).
Diagnosis procedures in the preceding servicing instructions have not covered the
identification oT (rouble caused by demagnetized tuning fork magnets, for reasons
of simplified Iion. Experience has shown that such trouble is very rare. If the move-
ment current hwithin the "OK" area of (he scale on the Test Set. the magnets arc
satisfactorily mngnvli/.ed
If the tuning fork magnets have lost most of their magnetism, the tuning fork will
fall to vibrate and the Test Set will Endicall Ivery high current-normally interpreted
as due to afaulty electronic circuit. If (he magnets have lost only aportion of their
magnetism, the tuning fork may vibrate but the Test Set will indicate that the cur-
rent is above the "OK" area of the scale In each of these instances, if an excessively
high current (and/or failure of the tuning fork to vibrate) cannot be corrected by
replacing the complete coll assembly—try substituting adifferent tuning fork.
If the tuning fork magnets have been demagnetized—the tuning fork assembly must
be returned to Dnlova for rcmagnetizing.
It is always good practice to check the adjustment of the indexing mechanism after
replacing the dial and hands. This is because the adjustment of the indexing mechan-
ism can change as »result of the slightest turning of the center second pinion when
the hand is applied.
14

MAY 24 :2S3
Indexing Mr*;hanisro— Inspection and Adjustment
The checking and adjustment of the ACCUTROX indexing mer.hanism is extremely
important to its operation. This is accomplished by closely controlling the alignment
and the depth of engagement of the index and pawl jewels and their interrelation.
Details of the step by step procedure necessary to properly accomplish these adjust-
ments are to be performed in sequence, as follows:
Note: Perform hnck mechanism inspection and ftdjutmenl Ipn&c 2U) before the
following steps.
I. Ghftdc thai stem ts in (running position). Remove cosing spring (2 screws) and
power cell (Fig. 14J.
CASINO SPRING
power aLI
UN S| Ml
CCU SlKAP
HMIHiHIWN
ii;Kl.W
Flg-U
15

2- The lower surfaces of the index and pawl jewels must be parallel to their respec-
tive fingers, as shown in Fig- IS. Correction of this alignment is rarely required.
It can usually be accomplished, if necessary, without breaking the cement attach-
ing the jewel to the finger by exercising watchmaking care- Grasp the finger with
tweezers, close Ira ihe jewel, and press lightly on the end of the jewel or finger in
the proper direction with Mgwood, to correct the alignment of jewel and finger.
Fi«. IB
F<H the proper operation, the two finger* muM he straight. Obviously, whi-n lbs
fingers arc UOftftttSfld Idisengaged from wheel), there will be nslight CUrVt
Both o( tin! p-wels itui'ti he perpendicular to liir wheel. Kitlu-r jewel can he made
papadlCUbu to the plane of the indr* whucl by grasping the jewel ftagtl iH
to its pinnini; point and twisting slightly. iSee Fig.l6.| Centering the index and/or
ptwl |«Wtl is accomplished by alignment ol the wptCtiMpost. Cently ItaM the
index Ot p-'wl pnwl by grasping or pushing the end of the post with tweezers or a
suitable screwdriver. (See Fig. 17.) Thin very slight bending of the post will raise
or lower the index or pawl jewel in rel.itinn tu the index wheel. Exercise normnl
watchmaking care in readjusting the various parts of the ACCUTRON indexing
mechanism.
NOTE.- Index nftMl
(petti nor shown
Fig. IB Fig. i-
16

:fiwy ^'«UD
3. Rotate index finger collet until index jewel completely disengages from index
wheel Observe gap between index gage and index finger. (See Fig. 18.) The gage
must not touch the finger, but should preferably be very close, say within one
index finger thickness- This, as you will see. will make it easier lt> perform step 4.
If gap does not meet requirements, bend index gage at its attached end until the
proper gap is obtained-
INDEX
WHEa

HAY 24 1969
7. Rolale pawl bridge cam until pawl bridge is in its maximum clockwise position
(maximum position in the direction lo disengage pawl jewel from index wheel|
The pawl jewel should not be touching the index wheel and nol more than one-
half its thickness away from the wheel. This distance may be adjusted usinc the
eoUe) adjusting tool.
BRIDGE
PIVOT ^-~> Index wfceel
SCREW f£j\^\ teeth nol
:\r:iIvisible al
*'this scale
PAWI
8RIUGE
LOCK
SCREW
LESS THAN V,
PAWL THICKNESS OF
BRIDGE JEWEL AWAY
CAM ER0M WHEEL
Fig at
8- li ii i'hij: tip of Test Scl lead into iSu i"«"I ikt movement holder. Insert lull
tip of other lead of Test Set undo •trap as shown in Fig. 21. Will tD 10
the nrr.1 <.l Teal Sei. turn nii.iry switch to "LOW AMPLITUDE" position If tuning
fork iIim". mil tkcgin to vibrate, ofl WVOM Bg will hr indicated on
ui.li-r id IVr.l Sri. Should Ihin OOOUT, Up HMVtntM holder lightly and fork will
alnrt. Current ruiuling will then drop to the lower end of "OK" jr«-j mr.lighlly
|h'1i»W
COPL fORM SCREW
JACK PLUG TIP CELL STRAP
in- ::i
9. Rotate ihe pawl bridge cam VERY SLOWLY in either direction (since it war. at its
maximum distance awny. rotating either clockwise or counterclockwise will move
the pawl jewel toward the wheel) until movement hegins to run. This can be seen
merely by watching the wheels thai arc visible. TURN THE CAM FARTHER IN
THE SAME DIRECTION UNTn. THE TRAIN STOPS. AND THEN* CONTINUE
STILL FARTHER UNTIL YOU REACH THE POINT WHERE IT STARTS AGAIN
AND CONTINUES TO RUN (Momentary hesitation permissible )
IB