Feeder capacity: All-Important
Danbury, CT, 18 Oct 2007
By John Pompea, President, Contact Systems, Inc.
reprinted with permission from May 2006 issue of U.S.Tech
Until recently gantry style placement machines were typically sold in pairs. The combined 8 mm feeder capacity of two machines was typically 160-200. With this capacity virtually any job would fit on the pair of machines. The newer high speed gantry machines, which can handle an expanded component range, are being promoted as a one machine solution. However feeder capacity of these newer machines is still in the 100 range. While feeder capacity is specified in 8mm, larger size feeders are commonly used on every job. If you try to make a comparison matrix of the feeder capacity for each size feeder, you will quickly find that most companies do not publish anything but 8 mm capacity on their web sites.
There are so many things to consider when comparing machines it is easy to gloss over feeder capacity. You may think 100 is plenty because you don’t have a job with that many different components. But when you add a tray magazine and a mixture of 12, 16, 24, 32 and 44 mm feeders you may find out you have what is effectively a 50-feeder machine. Many companies are now submitting their highest component count job to the machine vendor and asking if it fits and if it does, how many slots are still available. The last thing an EMS company wants is to be short on feeder capacity.
Changeover time is a much-touted buzzword from machine vendors. Loading feeders and exchanging them represents 90% of the changeover time. Obviously the more feeder capacity you have in your SMT line the more common parts you can leave on the machine.
OEM’s can take advantage of this fact more so than EMS companies which normally have to kit separately for each customer. In their case high feeder capacity can also reduce set up time because one job can be dynamically loaded while another is running - providing the machine has a fail-safe mounting system.
The two-machine line is often being replaced by a single, higher speed machine that can place a full range of components. Limited feeder capacity on the newer machines can be an issue. Companies evaluating machines should determine the machine’s true capacity to see if it fits their needs.
