When you look at the tiny mechanics powering a mechanical watch you can’t help but wonder, how does this all work? Where does the power for a mechanical watch come from and how are these parts all working together to accurately keep my time?
For many of our customers, their Beaucroft is their first automatic watch, their first ‘serious’ watch as they often describe it, and we are asked so many questions about how mechanical watches work, the difference between an automatic and manual watches and how them compare to a quartz watch. With these customers in mind we've created this bitesize guide to automatic watches and mechanical watch movements.
What is a watch movement?
A watch movement, also called calibers, are effectively the mechanical engines which power the watch and make the hands move in time.
Watch movement manufacturers will create many different types of watch movements, often using their own in house mechanisms. There are two key categories for these watch movements - mechanical and quartz watch movements.
What’s the difference between a mechanical and quartz watch movement?
Put simply, mechanical watch movements are powered solely through the winding of an inner spring known as the mainspring and are made up of many tiny gears to convert the springs energy it’s the hands movements, whereas a quartz watch movement is powered by a battery and features an internal electrical circuit to control the rate of the watches tick.
There is a neat way to quickly determine whether a watch features a quartz or a mechanical movement by watching the second-hand; with a quartz watch the second-hand will have a tick-tick motion and move once per second, due to the vibrations of the quartz crystal, whereas the second-hand on a mechanical movement sweeps in a smooth motion due to the smooth release of the springs energy through it’s gear system.
Typically, a mechanical watch will be more expensive than a quartz watch as it requires high levels of skilled processes to make and assemble the precision mechanical components. Interestingly a battery-powered quartz watch will most likely be more accurate than a mechanical watch, but it is in the craftsmanship and precision engineering of a mechanical watch movement which attracts the admiration of watch collectors.
What’s the difference between a manual and automatic mechanical movement?
Automatic watch movements are also known as ‘self-winding’ movements. They are given this name as they have the ability to automatically wind and recharge the movement through the natural motions of the wearer’s wrist.
For a manual or hand-wound mechanical watch, the user needs to regularly wind the watch by hand to recharge the mainspring that powers the watch, this can be done by winding the crown of the watch.
While there is something nice in the ritual of winding a hand-wound watch each morning, for our watches at Beaucroft we favour automatic mechanical movements - we like how easy and hassle-free they are for the wearer; the wearer can take comfort in the fact that their watch will keeps it’s power reserve topped up during natural use and won’t stop suddenly in the middle of the day, an automatic watch can also be manually hand wound by turning the crown, so it's a win-win!
How do automatic watches work?
An automatic watch movement features a freely rotating metal weight called the rotor, the movement from the wearer’s wrist causes the rotor to spin, as the rotor spins it automatically coils the mainspring inside the movement which provide the power for the watch.
What are the key parts of an automatic watch movement?
The mainspring acts as the power source for the automatic watch movement, the tighter the mainspring is wound the more elastic potential energy it stores.
When pulled out and rotated the crown is used to set the hands of the watch to the correct time, and when it is pushed in and rotated, it is used to manually wind the movement and coil the mainspring.
The gear train drives the timekeeping hands. The gear train is driven by the realising of the energy from the mainsprings.
Balance Wheel & Escapement
The escapement acts like a brake for the watch. It is made up of a wheel called the escape wheel and a latch like mechanism called the pallet fork.
The balance wheel swings in a precise rhythm powered in part by it’s own spring, the hairspring. As the balance wheel swings it bumps the pallet fork back and forth, this allows the escape wheel to move, gradually releasing the mainspring’s power in precise increments, this is called escapement.
The ticking sound you hear is from the arms of the pallet catching the tooth of the escape wheel, these are also known as the beats of the watch.
Jewels are tiny synthetic rubies that act as bearing for each of the moving parts in the watch, the axle of each part rests a jewel, and by being almost frictionless and are amazingly effective at ensuring the parts of the watch run smoothly for many years.
The rotor is the freely spinning metal weight which rotates the mainspring, which effectively recharges the movement. It is the key component that distinguishes an automatic movement from a manually wound movement. The natural movement of the wearer's wrist causes the rotor to spin, automatically charging the watch as it is worn.
Can you overwind an automatic watch?
No - thankfully the design of most modern automatic watch movements have smart mechanics to prevent this; When the mainspring is fully wound, a clutch attached to the rotor is engaged. This clutch prevents the rotor from winding the mainspring any further as it spins, preventing any damage from overwinding the spring.
Where are the best watch movement’s made?
Watches from Swiss, Japanese, and German movement makers are renowned for using the highest-quality materials to achieve great accuracy, precision, and reliability.
In our current watch range at Beaucroft we have chosen Japanese automatic movements from Miyota, we believe these movements give the best price to quality ratio and enable us to deliver reliable and precision made mechanical watches at an attractive price.
Do automatic watches last forever?
Yes, with proper care and maintenance an automatic mechanical watch can last a lifetime and beyond.
This is one of the things we love most about automatic watches. With the right craftsmanship and care, a great automatic watch can be maintained or brought back to life for the next generation to enjoy.
Automatic Watch Movements: Our final thoughts
The more we learn about the history and craftsmanship of automatic watch movements the more we fall in love with their engineering ingenuity. They are the beating hearts within our most treasured watches.
While many watches are bought based on looks, those with an interest and appreciation for the craftsmanship will enjoy knowing about the amazing inner working of their timepiece. With great care your beautiful automatic watch can last forever.