This time a nice Moeris watch. Moeris is a respectable Swiss brand from around the turn of the 19th century. Tissot bought and absorbed them around 1970. The movement is an in-house Moeris 10 1/2 D. A hand winding movement with 17 jewels. This particular one has an Incabloc anti-shock system. I’d date this watch to be from the 50s.
The watch didn’t run at all. Most of the times that’s a bad omen. It shows that there likely is some serious damage somewhere in the gear train or the escapement. The most common causes are tangled hairsprings and broken balance staffs. Anyway… on with disassembling.
Remember to remove any power from the mainspring first. This is to prevent damage when you’re working on the wheel train.
I remove the balance and the pallets. Normally, this would cause the gear train to turn if there is any residual power in the mainspring. I gently wiggle all wheels with a peg wood to see if it’s stuck. While I do this to the 4th wheel, everything comes alive. It seems something was blocking the 4th wheel and now the gear train is free and operational again. Sometimes luck will be on your side.
I lift the crown wheel and the ratchet wheel. Then I remove the broken case screw and lift the barrel bridge as well.
After that, I lift the train wheel bridge, the gear train, and the main barrel. What’s left is a driving wheel and a little bridge to hold the post for the cannon pinion in place.
This intermediate wheel is necessary to bridge the distance between the main barrel and the 3rd wheel. Usually, the main barrel will drive the 3rd wheel.
I clean out the dial side of the movement (motion works and keyless works). Remember to remove that intermediate wheel and its bridge. I pre-clean everything with a peg wood and put it in the watch cleaning machine.
The first parts I reassemble are the intermediate driving wheel and the cannon pinion post.
I then install the main barrel and place the wheels of the gear train in their correct positions. I Fit back the barrel bridge and guide the wheel pinions into the bearing jewels if they didn’t fell into place immediately. You can do that by keeping light pressure on the bridge with a peg wood and wiggle the wheels with another peg wood or (clean) old oiler.
I reassemble the wheel train bridge and screw both bridges down. Constantly check that the wheels still spin freely.
After that, I reinstall the crown wheel and the ratchet wheel with the click spring.
Flip the movement around to install the keyless works and the motion works.
I flip it back around and replace the pallets and afterward, the balance. The movement runs with an amplitude of 260 degrees, a rate of +5 sec and a beat error of 0.4 m/s. Not bad at all for the “old” mainspring.
This Moeris watch is ready to be worn for at least another decade.
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