Service Manual · Heritage 1854

The Model 81

9¾ Ligne Calendar · Model 80 Base

A calendar movement built on the Model 80. The entire calendar mechanism is housed between the date frame assembly and the dial, so it lifts off as a stack without disturbing the movement underneath.

Hand-wound Calendar V-Conic Model 80 Base

The Model 81 movement, dial side and movement side

Factory Service Manual · Model 81 · Dial Side & Movement Side

Ligne9¾

BearingsV-Conic

ConstructionTwo plate, full plates

Basic movementModel 80

CalendarBetween date frame and dial

Dial fixingFour tabs through the date frame

ManualService Manual · Model 81

Size (mm)18 × 21.95 mm

Height4.90 mm

Jewels0

EscapementPin lever

Beat rate18,000 bph

Power reserve41 h

Size in mm, height, jewels, escapement, beat rate and power reserve: ranfft.org

A Calendar on the Model 80

The TIMEX Model 81 is a 9¾ ligne calendar movement which utilizes the basic Model 80 movement with the “V-conic” bearing system and rugged two plate design. The entire calendar mechanism is housed between the date frame assembly and the dial.

Note: The movement underneath is the Model 80 and this manual does not repeat its servicing. See the Model 80 guide.

Exploded View

Model 81 · Exploded View

100Dial Plate Assembly

118Movement Plate Assembly

145/2Date Frame Assembly

180/1Barrel Assembly

201/12nd Wheel Assembly

2103rd Wheel Assembly

2274th Wheel Assembly

242Cannon Pinion Assembly

255Hour Wheel Assembly

260Minute Wheel Assembly

401/1Crown & Stem Assembly

416Ratchet Wheel

423/1Rocking Bar Bushing

437Rocking Bar Assembly

439Rocking Bar Spring

443Set Lever

450Intermediate Wind Pinion

450/1Winding Stem Pinion

452Wind & Set Pinion

495Ratchet Wheel Washer

495/2Winding Bridge

498/1Hour Wheel Washer

705Escape Wheel Assembly

710Pallet Lever Assembly

721Balance Wheel Assembly

740Hairspring Wedge Pin

751Dial

850Hour Hand

851Minute Hand

852/1Sweep Second Hand

2556Date Wheel Assembly

2557/1Date Ring

2576Detent Spring

5118Pillar Screw

5443Set Lever Screw

Disassembly for Cleaning

Getting the movement out of its case first? Case types and dust seals →

1 · Removing the Dial and Calendar

Remove the sweep second hand, the minute hand and the hour hand.

The dial assembly is clamped to the movement by means of four tabs which are inserted through slots in the date frame assembly into two holes in the dial plate, and then bent under the plate to secure the assembly. Bend the tabs slightly to free the dial from the movement.

Then lift off in order: dial, date ring, hour wheel washer, hour wheel assembly, date wheel assembly, date frame assembly, cannon pinion assembly.

Fig. 81.3 · Calendar stack

2 · The Dial Tabs

Cross section showing a dial tab passing through the date frame assembly slot and the dial plate tab hole, bent under the movement plate.

Fig. 81.3 · Dial tab

Reassembly

Lubricant change, June 1974: Timex Service Bulletin No. 111 replaced the factory oil for this model. Moebius Synt-A-Lube oil is used instead of Elgin M56B oil or Tenneco #415 oil. (It supersedes Bulletin No. 108.)

Assemble the detent spring, if loose, into the date frame assembly. Place the date frame assembly on the Model 80 movement, being sure the date frame bosses are located in the two holes in the dial plate. Then assemble in order: date wheel assembly, cannon pinion assembly, hour wheel assembly, hour wheel washer.

Lubricate the cannon pinion bearing area and the date wheel bearing area with fine watch oil, Elgin M56b in the factory. Position the date ring on the date frame assembly.

1 · Lubricating the Date Ring

Lubricate the face of the date ring and the detent spring with fine watch oil, Elgin M56b in the factory, as shown.

2 · To Position Hands for Proper Date Change

With the dial assembled to the movement, pull the crown and stem assembly into the set position and rotate the crown clockwise until the date starts to move. Continue to rotate slowly until the date jumps into place, then stop rotating. Replace all hands at the 12 o’clock position. Be certain the sweep second hand is set below the chamfer on the top of the staff.

Lubrication points on the date ring and detent spring

Fig. 81.4 · Date ring & detent spring

Hands & Date

1 · Positioning the Hands

With the dial assembled to the movement, pull the crown into the set position and rotate clockwise until the date starts to move. Continue slowly until the date jumps into place, then stop. Replace all hands at the 12 o’clock position, with the sweep second hand set below the chamfer on the top of the staff.

Cross section showing the sweep second hand set below the chamfer

Fig. 81.4 · Setting the hands

To set the date: pull the crown out to the set position and rotate the hands forward clockwise until the date in the window changes. The date may then be advanced rapidly by first rotating the hands backwards past 9 o’clock and then forward past 12 o’clock, repeating the cycle.

Setting the time correctly: The date may also be advanced by rotating the hands forward through 24 hours. After the correct date is set, remembering that the date change occurred at the equivalent of 12 o’clock midnight, set the time properly for AM or PM. Otherwise the next date change will occur during mid-day instead of at midnight.