Ultrasonic Cleaning and Watch Oil Lubrication Standards for Mechanical Camera Slow Shutter Mechanism Escapement Gear Train (Slow Speed Escapement)

1. The precision watch heart of the mechanical slow-door escapement (Escapement)

Mechanical cameras (such as Leica M3/M4, Nikon F/FM2, Olympus OM-1) rely on the shutter curtain to eject naturally at the high speed of 1/1000s; but in the slow speed range of 1 second, 1/2 second, 1/4 second, 1/8 second, and 1/15 second, they must rely on the slow escapement delay mechanism at the bottom of the fuselage:

1. Mechanical principles of gear train and hairspring flywheel:

• After the shutter front curtain is released, the connecting rod pushes the main gear fan of the slow door mechanism;
• The tooth sector drives a set of speed-increasing micro gear trains, and the end drives a reciprocating swinging balance wheel with an anchor pallet fork (Pallet Fork) and a star wheel (Escape Wheel);
• The pallet fork bites the swing damper back and forth on the star wheel with a very high frequency of "ta-ta-ta-ta", accurately consuming the energy of the mainspring. After a delay of a predetermined number of seconds, the connecting rod is released and the curtain closes.

2. **The mechanical origin of "traveling slows down or even stops":

• The shaft tip diameter of the slow door gear bearing is only 0.2 mm;
• Over time, the original watch oil dries up to form a microscopic viscous colloid, and the escapement fork balance wheel is blocked and unable to swing at high frequency;
• Setting the slow door to 1 second often takes as long as 3 to 5 seconds, or even the gear gets completely stuck in the middle and becomes paralyzed.

2. Modular disassembly and fully enclosed ultrasonic vibration degreasing

Many rough maintenance personnel spray rust remover into the gaps in the gears, which will only cause damage to the hairspring:

1. Module Removal:

• Remove the camera bottom cover or front panel, unscrew the two precision screws that fix the slow door delay mechanism, and remove the entire escapement gear module as a complete unit;
• It is strictly prohibited to blindly dismantle a single micro-gear (the internal hairspring is extremely difficult to rewind and reset!).

2. High purity no residual solvent cleaning:

• Prepare a small glass beaker and pour 30ml high purity industrial isoheptane or pure anhydrous ether;
• Suspend the slow door gear module and immerse it in the liquid;
• Place the beaker into the ultrasonic cleaning tank, add water and shake for 3 to 5 minutes;
• Under the impact of high-frequency cavitation microbubbles, the black aged oil sludge deep in the shaft hole is completely emulsified and peeled off, and the solution turns into turbid and light yellow.

3. Second rinse and hot air drying:

• Replace with new pure anhydrous isopropyl alcohol and rinse twice for 1 minute;
• Take it out and place it on dust-free paper, and blow dry it thoroughly with a hot and cold hair dryer to ensure that the surface of the gear appears dry and oil-free.
• Use tweezers to gently move the toothed fan: the star wheel and balance wheel immediately emit a cheerful, smooth, and extremely fast rotating buzz sound without any hindrance.

3. Swiss Moebius watch precision lubricant selection and lubrication specifications

Mechanical camera lubrication follows extremely strict physical boundaries - "It is better not to add more than to add more!"

1. The only choice of lubricant: Swiss top watch oil (Moebius):

• Moebius 9010 pure synthetic lightweight ultra-fine watch oil: used for high-speed rotating escape wheel and balance wheel jewel bearing holes;
• Moebius 8000 Natural Watch Lubricant: Mainspring gear journal for low speed and high torque;
• Do not use any sewing machine oil, machine oil or WD-40!

2. Ultra-fine oil pen micron oil dotting method (Oiler Pen):

• Use 0.15mm black ultra-fine metal oil pen tip;
• Touch the tip of the needle lightly in the oil droplet and pick up only a dust-sized droplet (about 0.001 ml) that is almost invisible to the naked eye!
• Place the edges of the brass shaft holes at the upper and lower ends of the gear with extreme precision (using capillary phenomena to allow a small amount of oil to penetrate into the shaft core);
• Absolute iron law: the tooth surfaces of the gears and the collision contact surfaces of the star wheel and the pallet fork must be kept absolutely 100% absolutely dry, and it is strictly forbidden to be contaminated with even a trace of liquid oil! Oil on the tooth surface will cause oil film adhesion during high-speed meshing, resulting in a sharp slowdown in travel time.

4. Accurate calibration of photoelectric shutter speed tester

1. Install the cleaned and lubricated slow door module back into the camera;
2. Speedometer sensor lighting test:

• 1 second (1.00s): the actual measurement must fall within the qualified range of 0.85s to 1.15s;
• 1/2 second (0.50s): the actual measurement must fall within the range of 0.42s to 0.58s;
• 1/4 second range (0.25s): The actual measurement must fall within the range of 0.21s to 0.29s.

3. Eccentric cam fine adjustment:

• If the overall speed is too slow or too fast, fine-tune the eccentric adjustment eccentric pin (Eccentric Cam) on the slow door base, fine-tune the initial engagement depth of the gear sector and the shutter connecting rod, until the travel time error in all gears is completely converged within the $\pm 10%$ international excellence standard.

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