For years, those familiar with Single Minute Exchange of Die (SMED) have been hearing how efficiency expert Shigeo Shingo helped automaker Toyota reduce setup time on its 1000-ton presses, going from four hours to just three minutes. An admirable achievement, but is it really necessary to change dies faster than you can pick up a happy meal at the local drive-thru?
Probably not, but it’s a sad fact that many shops waste time during set-up, and best measure their machine downtime in hours rather than minutes. This leads to oversized production runs and long lead times for finished goods, bloated inventory, product obsolescence and machine utilization figures that would have Shingo rolling in his grave.
Hopefully, your shop has already embraced some of the principles of SMED. Good shop organization, die standardization, efficient die transport and handling, making certain dies are properly maintained and ready to go—are all attributes of a well-tuned stamping house. If so, it might be time to make the move to quick die change.
Quick die change systems come in two types: hydraulic and magnetic. Like anything, each has its pros and cons, and there are proponents who will swear one is better than the other. The truth is that each has its place, and regardless of which best fits your shop, fast and accurate positioning is there for the taking. Prepare yourself for some sticker shock, though—you can plan on spending $10,000 at least to outfit a small press with quick-change, and maybe 10 times that for a large one.
George Munschauer, regional sales manager for AIDA-America Corp., Dayton, OH, explains that the level to which a shop carries its quick-change efforts (and the commensurate investment) depends on several factors, including part complexity and lot size, as well as the type of die, its weight and dimensions. For example, those shops doing simple parts and single-stroke processing are less likely to need the inherent accuracy that quick die change brings to the table. Says Munschauer, “but where automation is in place, or on progressive-type work using a coil-feeder, you’ll likely need positioning within a few thousandths if you’re going to assure good alignment. This is where quick die change systems really pay off.”