by John Ripka
If your punch press is not punching parts 100% of the time, it’s not making money
A punch press owner’s goal is to have the machine punching parts 100 per cent of the time.
Start with tool maintenance. Dull tooling and incorrectly setup punch assemblies result in lost time at the press, poor quality parts, scrapped material and possible machine damage. Tool maintenance personnel are responsible for sharpening, lubricating, assembling and storing tools. They are also responsible for staging tools, including setting proper tool length and verifying the die clearance for the material to be punched. Tools need to be prepared ahead of time so the operator can unload and load tools keeping machine downtime to a minimum. Not all tooling is interchangeable, so if you use multiple tooling suppliers, be sure to check for compatibility.
A tool storage system cuts down on time spent by operators looking for tools needed for the next job. When a shop has several presses using the same style tooling, there is a chance the needed tool is in another machine. A good tool storage and maintenance system includes accurate tool tracking at all times so tools can be ordered ahead of need. This should include other components such as guides, springs and strippers.
Include accessories, such as a high quality tool sharpening system. Also helpful are go/no go gauges to determine when a punch and die needs replacement, visual magnification devices to inspect tool cutting edges and lubrication tools. Shims are needed to assure tooling is setup at correct heights and lengths following maintenance. A vise is needed for tool assembly and inspection.
Engineering and programming can also help lower non-value added punching and increase efficiency by standardizing and reducing the number of hole sizes required. This can reduce the tooling needed and tool changes in the program. Both of these save tool loading/unloading time plus the time required to inspect and maintain excess tools.
Joint efforts by engineering, programming and operators often result in a wise decision to buy special application tools when required. These tools can increase productivity and minimize setup time.
A visible board showing standard and current tool loads should be located at each machine. This helps confirm that correct tools are in a machine and their location. Reserve sections of the turret for standard tools. This reduces setup time by allowing loading and unloading non-standard tools from the same area of the turret. This allows changing tools without rotating the turret.
Operators are responsible for maintaining press condition. This includes inspecting keys and keyways, replacing and adjusting them as needed and lubricating bores. Debris in and around the press should be removed frequently to prevent buildup and tool damage.
The fabrication team should know the limitations of their machines. This helps determine how parts are fabricated within limits, as well as produced at the lowest possible cost.
Communication is important to setup efficiency. If an operator suspects tools need sharpening, this should be conveyed to tool maintenance personnel when returning tools. The use of hit counters can also help determine when tools need to be sharpened, especially when tools are used in multiple machines. Communicating with programmers is important when trying to reduce fabrication time and increase machine up-time.
Forming tools need extra attention. Keep records of tool settings, stroke settings and machine settings used for specific material types and thicknesses. It helps reduce and eliminate setup time each time that tool is used after the initial setup. A simple spreadsheet that includes these values is helpful to tool maintenance personnel each time specific tools are setup for a job. The operator simply plugs in the values, making minor adjustments where necessary.
Tool setup efficiency is a total team effort. The ultimate goal of each team member is to reduce costs and increase profits, which are directly related to machine uptime. SMT
John Ripka is an application technician with Mate Precision ToolingPrecision Tooling.