Film Camera Body Slow Speed Escapement Gear Train (Slow Speed Escapement) Grease Cleaning and Rubber Bulb Blowing

The heart of the mechanical slow door: the precision miniature mechanical clock escapement

How can a camera tell the difference between 1/1000 of a second and a full 1.0 seconds?

• • • high-speed pure spring release * * : from 1/250 s to 1/1000 s high-speed, the front and rear curtains are fully dependent on the main spring for free ejection closure at maximum acceleration, without any deceleration mechanism intervention.
• • • The Escapement Mechanism in slow gear * * :
• when the shutter dial is set to 1/30s, 1/15s, or 1 second slow
• shutter linkage rocker mechanism into the bottom of the fuselage of a very small, very complex * * multistage cascade reducer gearbox and Escapement Wheel & Pallet * * ;
• the rear curtain spring is caught in the gears as the curtain opens just before the exposure
• the tiny escapement wheel and pendulum inside, like an old-fashioned mechanical clock, vibrate at a very high frequency from side to side (making a clear and melodious“Zi-zi-zi” sound similar to the tick-tock of a mechanical insect) ;
  Step by step gear rotation deceleration, the precise consumption of the set time (such as a full 1000 milliseconds) , release the claw, curtain can be closed!

Physical and chemical root cause of slow door sticking: resin curing of old mineral lubricating oil

The reason why old mechanical cameras freeze in the slow door is essentially the degradation of chemical grease:

• • • Resinification of organic grease * * :
• natural mineral oil or bone oil applied at the factory half a century ago;
• after long-term exposure to oxygen in the air and a small amount of ultraviolet radiation, the light lubricating hydrocarbon chain undergoes oxidative crosslinking polymerization;
• • • degradation from liquid grease to solid wax * * : the grease gradually evaporates and condenses, first into a syrupy glue for drawing, and finally hardens completely into a hard, dark, Dried Oil Sludge;
• • • complete asphyxiation of the tiny driving torque * * :
• the escapement wheel in the slow-winder gearbox is only a few millimetres in diameter and has very little spring torque (only a few millimetres) to turn and swing;
  When hardened sludge gets stuck between the teeth of fine needle-like gears and between the gaps in the ruby eye sockets, the feeble spring springs can not overcome the viscous resistance!
• the gears froze, the shutter shutter shutter shutter was locked, and the camera was paralyzed.

The Drop Flushing Technique

On many models (Nikon FE/FM, Canon, Barnacle) , the slow-door delay unit is installed directly under the underside of the underside, eliminating the need to remove the expensive pentaprism and the circuitry of the underside:

1. • • remove the metal cover to expose lesions * * :

• unscrew 2-3 tiny screws from the base plate and remove the base cover smoothly;
  Next to the battery compartment or through-piece connecting rod, you can clearly see the set of miniature copper gear box (slow door delayer) covered by small metal cover plate.

2. • • professional cleaning solvents * * :

• • • only recommended solvent: Real Zippo lighter oil (high purity light Naphtha Naphtha) * * ;
• • • physical properties * * : naphtha has a strong capillary permeability, can quickly penetrate the dissolution of dried-out old sludge in tens of seconds, and volatile extremely clean pure, * * 100% residue-free * * , it is perfectly safe to the metals around it and most engineering plastics.

3. • • intravenous cleaning technique * * :

• use a 1 ml medical syringe with a fine needle;
  With extreme restraint, take 1-2 drops of lighter fluid and drop it precisely on the escapement shaft of the slow gear box
• the solvent soaks into the gear and dissolves the sludge
• wind the camera immediately and release the 1-second slow valve. As the gears turn, the old black sludge is diluted and discharged;
• use a cotton swab to carefully remove the oozing black waste oil. Repeat 2-3 times until the solvent is absolutely clear.

High-purity Air Purge and dry/micro-lubrication final calibration

The end of the cleaning process will determine the life of the machine for the next decade:

• • • Air Purging * * :
• • • no residual liquid solvents after cleaning! **
• using a large-caliber, powerful, hand-operated rubber ear-wash ball (air-blowing) , blow vigorously into the gear gap for dozens of consecutive times;
• strong air flow will completely dry and blow through the remaining volatile solvents, while blowing away any microscopic paint residue dust that falls off.
• • • The ultimate lubricating commandment for a slow-motion mechanism: Dry Running is better than abusing grease! **:
• industrial clock mechanics subversive common sense: * * high-precision slow-door escapement pendulum in most cases should be kept absolutely oil-free (Bone Dry) operation! **
• many mechanical gears are completely dry and oil-free, with minimal air damping and maximum speed and accuracy;
• If lubrication is necessary, * * only a tiny amount of atomic-sized Moebius 9010 is allowed to touch the key main-gear shaft with the tip of a very fine needle * * never let a drop of oil get on the tip of the escapement fork!
• • • listen to the sound verification * * : press the shutter button at 1 second and listen to a series of happy, clear, non-dilatory hummingbird-like 't-t-t-t-t-t-t-t-t-t-t-t-t-t' sounds erupt from the depths of the floorboard, then, with a click, the curtain closes, and the mechanical shutter system is reborn!

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