Keeping Watch on Small Parts By Scott Rathburn
The average mechanical watch movement – say, from a Swiss Rolex automatic with date – contains around 135 individual parts. While some of those parts, such as the main plates, are relatively large (at least in watchmaking terms), the majority of them are quite small, often requiring magnifi cation to see clearly.
“The main plates are fairly big, but thin – from as thin as 1 mm to 5 mm,” explains Steve Cotton, owner of Micro Precision Parts Manufacturing Ltd. (MPPM), Qualicum Beach, B.C. “The small parts can be as small as 0.5 mm – too small to hold with your hands. You have to assemble them with fi ne tweezers and a 10-power loupe.”
Born in New Zealand in 1961, Cotton is a watchmaker by trade. He apprenticed for 4 years under his father, Peter Cotton, one of New Zealand’s top watchmakers, before passing fi nal exams at the New Zealand Horological Institute. After completing his apprenticeship, Cotton traveled to Neuchâtel, Switzerland, where he completed the Watchmakers of Switzerland Training and Education Program – “the most respected and highest-grade course in the world,” Cotton says. The young watchmaker rounded out his training with additional courses at ETA, SA (a primary supplier of high-end Swiss movements to the international watch industry) and Rolex, both in Switzerland.
The Island also proved home to a substantial population of clocks in need of restoration and repair – many requiring obsolete parts. It was the perfect opportunity for Cotton to return to his watchmaking roots. If he manufactured the obsolete parts himself, he reasoned, he could sell them for a profi t, and get the repair business. In 2004, he founded Micro Precision Parts Manufacturing to tap into the Island’s clock repair and restoration market.
Today, MPPM manufactures parts for and repairs high-quality vintage watches, high-end Swiss watches and vintage clocks. MPPM also has become a “go-to” company for micromachining parts for several other industries, including one of Canada’s leading robotics companies, and medical companies in the U.S. and Canada.
From Cutting Tool Engineering Magazine May 2008
It’s all about perspective. Steve Cotton, owner of Micro Precision Parts Manufacturing Ltd., got his start as a watchmaker, so his definition of “large” parts fits what many shops consider small. “If we are working outside of a 1" to 2" parameter, it’s a big part for us,” he said. Typically, parts are so small that 50 of them can be placed on a penny. Making small parts is not simply a case of dealing with smaller dimensions. All the elements of the machining system “have to work together,” Cotton said.
The Vancouver, B.C., shop handles production orders for as many as 30,000 pieces annually, but also machines single- digit runs of custom parts and replacements for obsolete items. Examples of the tiny, precise components the shop produces include miniature gears and gearboxes for the robotic industry and lens drive gears for cameras.
Cotton founded his shop in 2004, focusing on making parts for watches, especially gears. “We started servicing old clocks and vintage watches,” he said. “Half of them you can’t get parts for anymore. I investigated CNC machining to make some of the obsolete parts.”
He bought a benchtop CNC lathe and used it for a year. “Even though it was automatic to a certain point,” Cotton said, “it was still labor intensive.” To reduce tool change time and labor, he contacted Thomas Skinner & Son Ltd., a 104-year-old industrial distributor in Richmond, B.C., seeking advice on acquiring a CNC machine with an automatic toolchanger.