Patternmaking has been transformed from a craft skill into a high-tech computer-aided process, writes Karlin Lillingtonin Manitowoc, Wisconsin
LIKE A contemporary art installation, motors made entirely from deep red mahogany once hung incongruously on the wall of my uncle's business in the Wisconsin town where I spent many childhood summers.
But this wasn't art. It was business - or, more accurately, patternmaking (see panel), a blend of art, craft and engineering that has been replaced by the different art of information technology in the decade or so since my uncle retired and handed over the business to his son, Dan Place.
My uncle, Greg Place, was a patternmaker, a highly skilled, perfectionist trade requiring excellent maths, the ability to think in three dimensions, the eye of an artist and the hands of a surgeon.
From those able hands came motors and parts made from wood, which in turn became the patterns from which the final metal objects were cast at a foundry.
Among other projects large and small, Greg and his workers built the model for the engine of the Voyager, the aircraft that in 1986 made the first nonstop, nonrefuelled trip around the world and which now hangs in the Smithsonian institute in Washington DC.
Greg worked his way up from an apprenticeship in the 1950s (encouraged by his father, a carpenter, woodworker and machinist who worked at a foundry) to eventually take over Manitowoc Pattern and Manufacturing (MPM) from his boss in 1979.
Today at MPM, the patternmakers' wooden workbenches and walls of tools have been almost completely replaced by the clatter of networked, computer-driven machines, stacks of red epoxy resin for the patterns, and quiet computer rooms in which employees manipulate Cad (computer aided design) drawings.
The impact of IT on this niche sector is extraordinary. "The drawings come in as Cad, the model is in Cad, it's brought to the floor as Cad, and cut and modified from Cad," says Dan.
His father, on the other hand, spent four years as an apprentice, working for $1.20 an hour and learning maths, engineering, draftsmanship and woodworking skills. He was then thrown in at the deep end when he got a job with MPM - considered the best pattern shop in the area.
This area of the American midwest, with its German and Nordic immigrants with metalworking backgrounds, generated a great deal of large foundry work - building cranes, steam hoists and mining machines. "Some patterns were as big as a room," Greg recalls.
Dan's employees these days come in with technical degrees and computer science backgrounds. In a room behind the front office, two young men work at large PCs, examining three-dimensional drawings of the parts, or "tools", that will be made on the shop floor.
Drawings come in from a variety of Cad programs, and often need additional work because the clients did not understand that the walls they drew would be too weak for the part's purpose, or that many parts have areas that need to be padded out with "draft" - extra metal that will be machined off to make smooth surfaces. Understanding such issues is part of MPM's "value add", Dan says.
Greg notes that, in his time, such changes were made by the patternmaker and added to the wood design, along with bits of shaped leather and beeswax to correct the shape for casting.
In another room off the noisy shop floor, three more men at PCs determine how the dozen or so machines on the floor will cut and shape the epoxy or aluminium model, or machine the finished metal casing returned from the foundry.
"There's an encoder on each motor that feeds back to the computer, so the computer always knows the position of the object," he says.
The transition to IT had barely begun when Greg passed on the business to Dan. "I've already seen changes I never thought I'd see in my lifetime," says Greg.
Does he lament the waning of the patternmakers' skills? "You hate to see it go by the wayside and lose those talented men. It's a lost art - sad."
Dan says: "Probably the biggest difference is that we've gone from having the art and skill on the manual side to having the art and skill in a digital format. These guys all have talent and skill, just in a different form from my dad's time."
His vision of the future? "Eventually, you'll employ a lot of engineers and a lot of maintenance guys. You'll have robots doing the work, and people maintaining them."
What about the loss of the skills his father has? "If I have any regret, it's for the loss of respect for the trade and the artist," says Dan.
Patternmaking
PATTERNMAKERS CREATE the detailed models used to cast machine parts.
Motors - for cars, motorcycles, aircraft and boats - are a good example. The casing for the motor, and many of the inside wheels and other pieces, need to be designed first from some other material.
In the past, that material was usually mahogany or sugar pine because they are stable and do not warp. Creating the wood pattern was a highly skilled trade. "We worked to the thousandth of an inch," says retired patternmaker Greg Place. "It was strictly eyework, using ordinary rulers."
The patterns came from huge blueprints, up to 12ft across, provided by customers such as Chrysler and Harley-Davidson. The resulting piece was pressed into a mould filled with a sand and clay mixture and the mould pulled away to provide a well, ready for the casting metal at a foundry. Because different metals shrink by different amounts as they cool, patternmakers used "shrink rules" for each metal to ensure their wood pieces accommodated the final reductions.
Patternmakers also needed to add in gentle slopes and rounded edges to make the pattern slip precisely out of the mould - this is why motors do not have sharp boxy angles. Detailed parts all had to be cut with specialist tools and finished by hand.
Today, some patterns are still worked in wood, but the majority use epoxy resin or aluminium and are cut by computer-guided machinery.
KARLIN LILLINGTON
