Five draftsmen at Heatcraft had just six months to re-create detail drawings and update bills of materials for hundreds of existing air conditioner models.
When the Kirby Heat Transfer Division of Heatcraft Australia was asked to take over production of a sister company’s air conditioner line, it knew working from existing documentation was a bad idea.
“The other company was having consistency and warranty problems,” explains Joe Chabo, engineering manager of the division. “If we were going to improve quality, we needed to re-create the drawings and bills of materials to make sure they were correct.” With hundreds of different AC models, this was a tall order. It was even more challenging because Joe Chabo’s team had only six months to do the work.
Impossible with 2D
Joe Chabo realized his division would not make the deadline with its 2D CAD system because 1) every drawing would have to be started from scratch and 2) many hours would be needed to create and check BOMs. Worse, 2D could cause the same quality problems the sister company had because it is so difficult to detect interferences on drawings. The division decided to use solid modelling instead, choosing Solid Edge® software in part because it appeared to have the shortest learning
curve. (Its sheet metal capabilities were also important.) The draftsmen modelled each AC unit – internal assembly and sheet metal cover – in solids, then checked the models thoroughly for interferences. They took advantage of Solid Edge sheet metal tools to automatically unfold complicated parts. Only when they were sure the models were accurate did they spin off 2D views for manufacturing.
There wasn’t time for training; the draftsmen learned Solid Edge as they worked. Very quickly, they were creating complex assembly models, and easily visualizing problems they would have missed with 2D. Producing the manufacturing drawings was the simple matter of selecting the desired views of the solid models and letting Solid Edge generate the drawings automatically. BOMs were also produced from the solid models, eliminating the need to type lists and double-check for errors. Documentation for 100 air conditioner models was completed by the six-month deadline. Joe Chabo estimates that it would have taken at least twice as long with 2D CAD. More importantly, the documents were accurate. “The better quality of the drawings, with more useful views, improved the overall quality of the product,” he says.
Automating heat exchanger design
Having accomplished its mission of delivering documentation for 100 air conditioners in half the time, Heatcraft’s next use of Solid Edge involves automating heat exchanger design. The company will attempt to link common design elements (such as the coil block) to a spreadsheet, then change numbers in the spreadsheet to have Solid Edge quickly generate new designs.