The Craftsmen Behind Precision

Every restored wall clock in our workshop bears the mark of a specialist with decades of experience in manual calibration and fine assembly. The deep knowledge of vintage mechanisms, from the escape wheel to the balance wheel, is the legacy we put to work every day.

master watchmaker

Catrina Ionescu

Specialized in calibrating the balance wheel and escape wheel for 19th-century wall clocks. She has restored over 300 mechanisms with spiral springs, correcting deviations of a few seconds per day through fine filing and manual pivot adjustment.

 master assembler

Vasile Trifan

Expert in fine lubrication of axles and cleaning wooden cases without affecting the original finish. He uses exclusively natural oils and squirrel hair brushes to remove dust from inside the case, preventing spring oxidation.

 gear wheel restorer

Ionela Popescu

Passionate about tooth geometry and metal wear, Ionela manually rebuilds worn gear profiles, ensuring perfect meshing. Each tooth is polished with slate stone and checked with a watchmaker's loupe to eliminate any deviation.

Behind every precise tick-tock stands a team that knows every screw, every spring, and every tooth. Discover how we work.

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The Mastery of Hand Watchmaking

Every gear, every pivot, and every spring are links in a chain of precision. Our project exists to preserve and pass on the art of manual calibration of mechanical wall clocks – a discipline that demands iron patience, a keen eye, and respect for every detail of the vintage mechanism.

Checking the Escape Wheel Each tooth of the escape wheel must be perfectly symmetrical and hand-polished. A simple fine filing can correct deviations of a few seconds per day, transforming the spring's energy into regular impulses to the balance wheel.

Fine Lubrication of Axles Special oils, applied in microscopic quantities with a watchmaker's needle, protect the balance pivots and barrel bearings. Any excess attracts dust and accelerates wear – which is why every drop counts.

Cleaning the Wooden Case Dust and old grease are removed with a soft squirrel hair brush and a slightly alkaline solution of natural soap. Slow drying at room temperature prevents spring oxidation and preserves the original finish of the precious wood.

Effect on the Customer A mechanism calibrated according to these principles works perfectly for decades, without visible deviations. You benefit from a clock that not only measures time but honors it with every regular and durable tick-tock.

Frequently Asked Questions About Manual Calibration

Clear answers for watchmakers passionate about vintage wall mechanisms.

How often should the balance wheel of a mechanical wall clock be checked?

The balance wheel is the heart of the mechanism and should be visually inspected once a year, preferably before the cold season when temperature fluctuations can affect its elasticity. A complete check, including cleaning the pivot and the hairspring, is recommended every 3-5 years, depending on how much dust enters the case. If you notice the clock losing or gaining more than 2-3 minutes per week, it is a clear sign that the balance wheel needs a fine adjustment of the hairspring length.

What type of oil is suitable for the gear train axles?

For vintage mechanisms, natural oils of animal origin (e.g., modern synthesized whale oil) or specially formulated vegetable oils for watchmaking are the safest. Modern synthetic oils can be too fluid and may migrate into the bearings, attracting dust. Apply a microscopic amount – just enough to moisten the tip of a watchmaker's needle – to each pivot of the intermediate wheels and the escape wheel arbor. Strictly avoid lubricating the teeth themselves, as this would disrupt the gear train.

How can I clean dust from inside a wooden case without damaging the mechanism?

The first step is to carefully remove dust with a soft squirrel hair brush or an antistatic brush, working from top to bottom. Never use compressed air – the pressure can push dust into unprotected bearings. For older dirt, lightly moisten a microfiber cloth with a natural soap solution (neutral pH) and wipe only the interior wood surfaces, keeping the mechanism away. Allow the cases to dry completely for 24 hours before reassembling the clock.

What tools are essential for precise manual calibration?

A basic set includes: a watchmaker's loupe with 5x-10x magnification, fine curved-tip tweezers, an oiling needle, a balance wheel adjustment key, and a soft plastic hammer for adjusting wheel positions. For accuracy verification, a mechanical chronometer or a frequency measurement app (e.g., based on the microphone) can help you identify deviations of a few seconds per day. All tools must be demagnetized – a simple demagnetizer is useful.

How does the escape wheel influence the overall precision of the clock?

The escape wheel is the link that converts the continuous energy of the mainspring into regular impulses to the balance wheel. Each tooth must be perfectly symmetrical and hand-polished, otherwise the balance wheel receives uneven impulses, leading to time deviations. A simple fine filing of a worn tooth can correct errors of up to 10 seconds per day. Visually inspect each tooth under a loupe – any sign of asymmetric wear or chipping requires immediate intervention.

What is the most common mistake when lubricating axles?

The most common mistake is applying an excess of oil. A drop that is too large can run onto the bearings and attract dust, forming an abrasive paste that prematurely wears the axles. Also, many beginners lubricate the gear teeth, which is completely wrong – oil should only be applied to the pivots (ends of the axles) and the bearings. Use an oiling needle and apply such a small amount that only a slight sheen is visible in the light.

Contact a manual calibration specialist

The Mastery of Manual Calibration

Builtonprecision brings together enthusiasts of traditional watchmaking from Romania, who restore and regulate vintage wall mechanisms. Every gear, every pivot, and every spring is treated with unwavering patience, respecting techniques over a century old. We work exclusively with classic mechanical watches, where precision is not bought, but built tooth by tooth.

The manual calibration of a wall clock begins with a deep understanding of the balance wheel – the heart of the mechanism. This oscillating wheel vibrates at a fixed frequency, usually 18,000 beats per hour, and each oscillation is controlled by the balance spring. If the spring is slightly deformed or incorrectly lubricated, the entire rhythm of time is disrupted. We adjust the active length of the spring by micrometrically moving the regulator index, correcting deviations of a few seconds per day. The escape wheel is the next critical link. Its teeth must be perfectly symmetrical and hand-polished with Arkansas stone. Any asperity or asymmetric wear produces uneven impulses to the balance wheel, generating irregular ticks. We use 10× magnifying loupes and fine steel files to correct each tooth, then check the clearance with an optical comparator. A difference of 0.02 mm in the depth of a tooth can mean an error of 15 seconds per day. Precise assembly of the axles requires fine lubrication, applied with a watchmaker's needle. Natural animal-based oils – such as whale oil or refined olive oil – are preferred for vintage mechanisms, as they do not attack old brass and do not oxidize quickly. We apply a microscopic amount, approximately 0.1 µl, to each pivot of the balance wheel and to the escape wheel bearings. Excess oil attracts dust and creates an abrasive paste that prematurely wears the axles.

Essential Steps for Mechanism Inspection

  • Visually inspect the balance wheel and spring with a 10× loupe – look for deformations, oxidation spots, or traces of old oil.
  • Check the symmetry of the escape wheel teeth with an optical comparator; correct asymmetries with fine steel files.
  • Clean the dust inside the wooden case with a soft squirrel hair brush, without touching the springs.
  • Apply natural oil to the balance wheel pivots and escape wheel bearings using a watchmaker's needle.
  • Measure the amplitude of the balance wheel oscillations with a mechanical chronograph – it should be between 270° and 310°.
  • Adjust the spring length by micrometrically moving the regulator index, correcting deviations from 0 to +5 seconds per day.
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