Time for a punch tooling reorg?

A cabinet with clearly marked sections includes specially designed trays to hold and protect dies. Photo courtesy of Wilson Tool International.

When it comes to productive punching, the fewer tool changes the better. Some steps to keep the machine running can be taken before the order hits the floor. For example, extra time and effort at the design stage may make it possible to produce a component with tooling already in a turret. Or a shop with multiple machines can schedule work orders based on the tools loaded in specific machines. One machine might be set up for thin materials with smaller die clearances, while another produces parts from the thicker materials.

But changeovers are inevitably a fact of life. Today’s focus on shorter runs and high-mix, low-volume production, added to the fact that all tooling eventually needs sharpening or simply wears out, means that at some time the machine will need to pause to swap out tooling assemblies. Good organization, however, can keep that time short and production time long.

A few basics to good punch tool organization that leads to smooth, quick changeovers are a strictly monitored plan so tools are easy to find; proper maintenance so they are always ready to produce; careful scheduling so tools can be gathered and staged for one job while the machine is producing another; and using automation to its best advantage.

Where Are They?

How tools are organized essentially comes down to how many machines and punching tools a company owns.

“I’m estimating that if a company has five or more punching machines, they are collecting enough tools and can justify a toolroom with a dedicated attendant,” said Ron Windingstad, product engineering manager at Mate Precision Tooling. “A well-trained toolroom attendant will keep the tools in good condition and know where every tool is in the shop so the operators can keep the machine running.

“The centralized area would have all the cabinets, grinders, spare parts, and assembly and disassembly hand tools. The biggest advantage is that the attendant will know how to sharpen and care for the tools, and he takes responsibility for their maintenance. Some have a hot wax station and dip the punch tips in the wax before storing them. That’s how we ship them, so why not store them the same way?

“Having a toolroom is a logical choice even for a small company that has different types of presses with different tool styles. It helps prevent tools from being intermingled on the shop floor.”

A centralized toolroom doesn’t have to be manned, but that puts the responsibility for retrieving and returning tools to their proper places and their maintenance on the operators.

Point-of-use storage can work particularly well with machines used for high-volume runs, where changeovers are minimal. Storage may simply be the replacements for that machine’s tired tooling or include assemblies that are dedicated to that machine.

John or “J.J.” Johnson, punching product manager at Wilson Tool International, said, “When companies store the tools by the machine that uses them, the operator is typically responsible for their maintenance.”

Tooling stored on an open shelf collects dust and grit from the shop atmosphere. Photo courtesy of Mate Precision Tooling.

Then there’s the hybrid. Tools used frequently in a specific machine are stored nearby and those that are used only occasionally are in central storage.

Cart or Cabinet?

The number of choices for storing tools is as many as the number of shops. Although specially designed carts and cabinets are available, many companies create their own storage units.

Mobile carts move assemblies from a central storage location to the machine and provide a place for staging. Generic carts work but may not protect tools during transit or assist with directing where a new tool assembly should be loaded.

Some customized changeover carts transport the tooling and assemblies in an upright position to protect their edges from banging into other surfaces as the cart rolls over uneven shop floors. It’s difficult to damage the coatings, but metal-on-metal contact of a punch or a die opening can chip the substrate.

“Some carts have mock turrets that mimic the machine,” said Windingstad. “Tools are put in the station on the cart that corresponds to the station in the machine. This type of cart is gentle on the tools, and the operator doesn’t have to think about what station the assembly goes into.”

In addition to being mobile, an advantage to a cart is that tooling is visible. It’s obvious if a tool is broken, chipped, or cracked and shouldn’t be used. A disadvantage is that tooling stored on the surface of the cart can collect dust and grime from a shop’s atmosphere.

Cabinets, whether generic or tooling-specific, are the reverse. Doors on the cabinets can protect from airborne dirt, but once they are closed, damaged tools can be out of sight and out of mind until they are needed for another run. That can cause a delay in changeover time while a tool is ground or a functional tool is tracked down.

Whatever type of storage system is used, tools are typically stored by size or type of punch. “Multiple dies for a punch might be stored with the assembly,” said Johnson. “Small tools lend themselves more to a cabinet drawer and large tools to a shelf. For example, the A and B station tooling might be in a cabinet, and the C, D, and E station tooling that can weigh up to 50 lbs. will be on a shelf.

“However they are stored, metal-to-metal contact with the cutting edges should be avoided. If the dies are stored vertically, there is less of a chance that anyone will set something on them and ding the edges. Also, always clean and lubricate before storing so the tooling won’t malfunction.”

Windingstad said, “Tools are usually top-heavy. They can tip easily, so wherever they are stored there should be receptors--holes or pockets-- to provide support. Assemblies or single tools also can be stored in their shipping cases,” said Windingstad. “We’ve seen companies that put tools in a cardboard or wooden box with nothing insulating them from banging together. These tools can represent thousands of dollars of investment. A little investment in a storage system and time for maintenance are definitely worthwhile.”

Receptors hold and protect tooling in a point-of-use shelf. Photo courtesy of Mate Precision Tooling.

What Are They?

Simple colour coding can work to identify what a tool is and where it belongs. A laser-marked matrix code applied by the tooling OEM can go further. It can be scanned to identify the individual tool on the shop floor and to provide information for reordering. Whatever method of tool identification is used, the system needs to be understood and used by everyone in the shop.

“Some companies will paint the tools colours to match machines, shifts, storage areas, etc. Walking through the shop, if you see a green tool next to a group of red ones, you know it’s incorrect,” said Windingstad.

“2-D bar codes printed on tooling or labels on tooling and a scanner can allow a company to create their own tooling storage, tracking, and inventory system. That kind of tracking allows the manufacturer to use customer portals and access points through the internet to track the tooling that has been ordered and use that information to reorder.”

Labeling the storage areas for assemblies or individual tools can help ensure that they will be returned to the proper place. A space holder of some type can reserve a tool’s location when it’s in use, working almost like a shadow board. An empty spot without a space holder can indicate that a tool needs to be tracked down.

Some tools have an area for marking. Johnson said, “Some tools have a white space where the manufacturer can indicate the tool’s size and shape or other critical information.“When it comes to integrating with machine automation, we see shops using the various forms of bar coding and tool tracking identification offered by OEMs. These systems have been available for a while but are becoming more adopted.”

How Can Machines Help?

Punching machines are becoming more intelligent with more advanced software. They are getting the job done faster with less operator interaction. Equipment with automatic tool changers paired with tool storage cabinets is making changeovers faster and easier.

“We’ve been seeing a real movement toward automation because of improved operator safety, faster production, and, now, control of tooling storage,” said Johnson. “OEMs are attaching a tool crib to the machine, and the robotics pull from that inventory of assemblies.”

Perhaps there is only one caution. Windingstad said, “If you have 100 or 200 tools in an autoloading system, the operators don’t get to see or touch the tooling to identify if there is a problem. A regular schedule should be established to remove, check, and maintain the tools.”

Punching tool organization, however structured, should include maintenance of all tools. Scheduled maintenance plus constant monitoring for tool wear and damage can help to prevent quality problems and unanticipated downtime caused by tool issues.

Take Advantage of Software Advances

Machine tool manufacturers have aggressively addressed the traditional issues involved with setting up a turret punch press, with many of the changes reducing time needed to track tooling and complete tool changeovers.

Small tools and accessories can be neatly stored in a drawer. Photo courtesy of Wilson Tool International.

Donald Angel, lead applications engineer for fabrication products at Murata Machinery USA Inc., said that keeping up-to-date on control software can make tooling organization easier.

“Control systems in turrets can assist the operator in dramatically reducing setup times and errors. That and automation will provide a tremendous boost in green-light time.”He listed some helpful features developed for the Motorum® series software. It can:

• Maintain an accurate turret layout on the control, eliminating manually maintained boards.
• Immediately identify if a tool change is needed when a program is selected.
• Use a scheduling function to allow a single tool setup for multiple programs.
• Automatically update programs and identify tools in the wrong stations.
• Automatically reorganize tools in the turret to allow a single setup.
• Maintain forming tool information that automatically loads based on material type and thickness.
• Maintain tooling hit counts to assist in setting up a regular tooling maintenance schedule.

Mate Precision Tooling, 800-328-4492, www.mate.com

Murata Machinery USA Inc., 704-875-9280, www.muratec-usa.com

Wilson Tool International, 800-445-4518, www.wilsontool.com

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