Peter Ulintz Peter Ulintz
Technical Director

Modern Four-Slide Technology

May 21, 2019

This month’s article concludes a three-part series on four-slide forming processes. Following articles on slide forming processes (April) and four-slide tooling (May), this month we look at modern four-slide controls and servo-drive technology.

Today hundreds, potentially thousands, of traditional mechanical four-slide machines dating back to the 1960s (or earlier) still operate, and traditional slide forming remains an effective process for manufacturing small, intricate parts. Even so, there are limitations.

Modern four-slide forming equipment includes servo-driven systems.

For example, complex mechanical motions and timing sequences require setup technicians and operators to have more training and higher skill levels than necessary for a conventional press. Moreover, the setup process can be very time-consuming as it calls for the following:

  • Combination of standard and special cams to attain the slide stroke and timing necessary for forming the part around the center tool;
  • Slide-tooling adjustments to attain part quality, requiring the setup person to advance or retard the timing on the cam;
  • Feed-length setting, recognizing that it may require further adjustment based on the amount of material stretching;
  • Press-station adjustment for achieving proper die-shut height, the distance between the bottom of the ram and the top of the press bed or bolster at the full-closed position (e.g. 270-deg. die-shut height for a 180-deg. feed);
  • Passing of the wire or strip through the feed mechanism and into the first station of the progressive die, if required;
  • Cycling of the machine by hand and engaging the feed when the press is at the full-open position;
  • Continued cycling of the machine by jogging or turning the machine by hand, through the die and to the cutoff station, where adjustments are made and lengths of cutoff blanks verified;
  • Continued jogging or turning of the machine by hand, going through several cycles of forming to make a few parts; and
  • Tooling adjustments (refitting or regrinding may be necessary) to bring parts within tolerance.

The lack of modern controls and servo technologies restrict setup time, part complexity and production efficiency when using mechanical slide forming machines.

Although A.H. Nilson Machine Co., U.S. Baird Corp. and Torin Corp., the Big 3 of traditional four-slides no longer exist (see April MetalForming, page 19), several domestic and international machine builders offer modern four-slide forming equipment, including servo-driven systems. When compared to traditional mechanical slide forming, the servo-driven systems provide greater versatility and flexibility to program slide motions, interchange components and store part-specific machine programs. Other benefits include reduced setup time, sometimes less than 1 hr. In addition, modern equipment eliminates the need for new cams requiring significant timing changes and related expenses. Full tool compatibility with select mechanical four-slides also makes it possible to run existing production tooling.

Advanced, servo-drive slide forming elevates production analysis and adjustments to a new level. Integrated sensors within the servo controller measure and analyze various process parameters in real time, including distance, torque and temperature. The controller automatically compensates for changes or shuts down the process. It even can alert operators or supervisors directly on their smartphones or other smart devices.

New functionality and programming ability also change the role of the tool designer and tool builder. Most CAD systems support tool and machine motion simulations, a technology routinely used to evaluate interference and optimize press/tool motion profiles for progressive and transfer die applications. Technology also exists to enable the timing chart developed from CAD simulations to load automatically as motion profiles into servo-controlled four-slide machines.

Advance tooling strategies also allow standard modules to quickly adapt to a plug-and-play programmable system, including the radial grip feeder and presses, as well as thread forming, screw insertion, contact welding and assembly capabilities.

In the future, additive metal manufacturing, or 3D metal printing, may dramatically reduce the time required to create slide tools. Tooling that traditionally takes a month or more to complete using traditional toolmaking methods could be 3D printed, machined and ready for use in a week. MF

Author’s note: Thanks to Bihler of America for contributing to this month’s column. 

Industry-Related Terms: Run, Slide Forming, Stroke, Torque, Transfer Die, Transfer, Bed, CAD, Center, Die, Forming, Functionality, Ram
View Glossary of Metalforming Terms

Technologies: Other Processes


Must be logged in to post a comment.
There are no comments posted.

Subscribe to the Newsletter

Start receiving newsletters.