Manufacturing Strategy Saves Tier One Suppliers Time and Cost

Manufacturing Strategy Saves Tier One Suppliers Time and Cost

"A flexible machining system strategy from Heller Machine Tools allows manufacturers to ramp up and debug production cost-effectively, change to a transfer system as production increases, and just as economically ramp down production as the product life winds down," stated a Heller spokesperson. This strategy is designed to make efficient long-term use of capital, permit agile response to markets, and provide a flexible production system that meets long- and short-range manufacturing goals.

When employed at automotive manufacturing plants, this approach often utilizes workholding fixtures on machining centers for about the first 12 months of production, fixtures which can be used later on a transfer line. For example, at the introduction of a new part, 30 machining centers could take on operations 10, 20, 30, 40; this would be suitable for volumes up to 50,000 per year. If and when a higher volume is required, Heller will reconfigure the production capability and utilize the machining centers for operations 10, 20, 30 only and the 40 will move onto the transfer line. The fixtures and part clamping will be the same, saving time and cost for the end-user.

In a recent example on the Heller assembly floor in Troy, Michigan, two 14-station flexible palletized transfer systems combined with 30 horizontal MC16 machining centers for machining up to 65 transmissions an hour (gross). The FST is fully enclosed and includes mist collection. Operations performed include milling, drilling and tapping with multi-spindle heads, boring, as well as 3-axis units with automatic tool change.

These Heller MC16 machining centers - which are used to machine all the flexible features in the early design phase - include HSK 63 spindles. The FST contains the part features that are critical to the functionality and quality of the part allowing for cost effective part traceability and quality control. Using the same size spindles on the transfer line and machining centers allowed the customer to use the same tooling, saving cost. This approach also allowed the customer to make adjustments for part design changes without the expense of re-engineering a transfer line.

An additional option is the addition of a park (buffer) section to the return conveyor, which contains a full alternate set of fixtures. For example, transmission size A uses 14 pallets requiring tool set A and program A. With a B set, the customer can quickly change over to pallet, tool and program B. This approach is effective when producing a family of parts.

At the beginning of a product life cycle, customers may start with machining centers, and, as the product volume increases, they can move into transfer lines. At the end of the life cycle or as volumes drop, these companies can move back into the machining centers.

To help its customers implement this flexible production strategy, Heller has engineered production-machining centers (single and twin spindle), head changes, and transfer lines plus common interfaces to permit the exchange and application of system components.

The same fixtures and tooling for the ramp-up and for the ramp down can be utilized. This permits more efficient use of capital, which is especially important for first tier suppliers, who never know what will be the life cycle of a product. Standardized interfaces between machining units and heads allow users to exchange pallets and employ a new set of multi-spindle or conventional machining heads. With new tools and CNC programs, they can basically retool their entire machining system.

Interfaces on Heller FST (Flexible System Transfers) and HCS (headchangers) are designed identically so a user can utilize the entire range of Heller applications without necessarily buying a new machine tool. Heller had a situation where it took the heads off a transfer line and put them on a headchanger's machining centers to quickly accommodate a production change at the customer's plant. A Heller solution to meet a customer's production needs can vary in response to volume needed, plant location, and related labor costs.

According to a Heller spokesperson, nearly all the first tier suppliers are forced to move in this direction, as they typically do not have long-term contracts. So, if they want to be careful with their investment, they need to be able to process various products on their equipment.

"If you look at the launch curve of a tier one supplier, there is a big investment during the first year of production as the new product's design wrinkles are worked out," stated a spokesperson. "Production is on the machining centers in the first year, and the machining centers are flexible enough to accommodate the part changes that occur. Then as the design stabilizes after the first year, you go to the higher volume transfer line as volumes are ramped up and design changes are fewer."

"Product people like the Heller machining center approach because it permits part design changes as little as four months before machine delivery; changes are accomplished in fixtures and tooling," the spokesperson continued. "With transfer lines, the part design must be finalized at least eight months before the machine is to be delivered. With the Heller approach, the product people effectively gain four months to finish their job, and the manufacturer can be much more responsive to the market."

For more information contact:

Heller Machine Tools

1225 Equity Drive

Troy, MI 48084

248-288-5000

Fax: 248-288-9560