Archive for March, 2015

Lean Ammunition Manufacturing Part II

March 11, 2015 by MarkC

Today’s brass case factories operate on the principles of traditional mass production techniques, developed in the early 1900’s.  In an effort to maximize efficiencies, machines are grouped in common departments, turned up to run as fast as possible and large inventories are used to buffer inconsistencies.  Machines are difficult to set up and adjust.  Specialized technicians are required to make changeovers, sometimes taking several days.  High inventory levels drive slow process speed, with as much as 4 Months inventory from beginning to end.  It’s impossible to stop production if a defect is discovered; it’s easier to add 100% inspection at the end of the process.  Lastly, today’s ammunition plants are loud and earplugs are required everywhere on the shop floor. It’s impossible to have an understandable conversation.

Setpoint has designed a brass case U shaped cell (shown below) that positions the operator on the inside and available to service all machines.  All tooling and equipment needed to produce a brass case, from first draw to final anneal, are positioned around the U.

Setpoint Case Line

Starting with first draw, brass cases are sequentially processed through each machine until the case is completed.  It is designed to hold 15-30 minute buffers between each machine and takes approximately 4 hours to complete a case from beginning to end.  Including 4 anneal and 5 individual wash operations.

Quality is monitored using statistical process control (SPC) sampling plans at an inspection table in the middle of the cell.  Adjustments are a snap with servo linear actuators.  When a machine requires an adjustment – the operator simply enters an offset on the touch screen and the dimension is adjusted without stopping the machine.  Capabilities of 6 sigma or better are common with this servo actuated technology.

Each machine is designed with versatility in mind.   The cell offers optional calibers between .223 through .338 Lapua.   Quick-change concepts have been incorporated, similar to the early days of Toyota.  Each machine is capable of 30 minute or less changeover from one caliber to another.

An intriguing aspect for the cell is lack of loud noise, having employees engaged in the continuous improvement process is mandatory in any lean organization.  Conversations are possible inside the cell without yelling through earplugs.

Labor content is low.  The inside operator tends all machines and conducts SPC inspections.  An outside operator monitors hardness testing, chemistries and minor machine maintenance.  Status lights (Andon) are on each machine providing quick operator feedback when machines need attention.  It’s also important to note that overhead support for the cell is significantly less than traditional manufacturing layouts.  This is because a connecting process using a cell requires less production control, less process/quality engineering and less production supervision.

As with the auto industry in the 1980’s, it’s time for a lean revolution in the brass case ammunition world.  Improved quality, low inventories, agile/versatile capacity, lower operating costs, lower overhead costs, clean processes and a quiet production environment are a few of the benefits.  Join the revolution, call Setpoint Systems at (866) 532-6856, or check us out online at www.setpointusa.com.

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