Page 23 - Metalforming Magazine April 2022

“We see an opportunity for metal formers in what we refer to as D2 upgrade materials,” he says. “There’s a desire to solve the challenge of com- mon D2 die material—large carbide particles that prove unfriendly for pol- ishing. Consider upgrading the die material if you’re looking for extreme performance.”
Mind Feed-System Settings
to clear working stations in the die. “The downward travel of the coil stock during die closure pulls addi- tional material through the feed unit while the feed roll remains open,” he says. “Should the feed roll close before the stock lifters return to their full-up position, extra material becomes trapped between the die and feed. This extra material pushes the strip forward when the pilots exit the strip, causing
the next feed progression to appear long.”
Press operators must take care to assess this issue properly to avoid prob- lems.
“Incorrect identification of this problem,” Ulintz says, “may cause the press operator to begin making pro- gram adjustments to the feed to com- pensate for timing errors with the pilot release.” MF
Beyond die materials and coatings, metal formers greatly affect tool per- formance in the press. This includes feed-system setting during job setup. To ensure proper performance of tool- ing in the stamping press, avoid incon- sistencies in product quality, and min- imize the likelihood of tool breakage or premature tool wear, stampers should strive for proper setting of the feed system.
That’s the word from Pete Ulintz, technical director for the Precision Met- alforming Association and author of the monthly Tooling By Design column in MetalForming magazine.
“Setting the feed system properly, including the pilot-release function, often proves challenging for the die setter, yet is critical for successful pro- gressive die stamping,” Ulintz offers. “While suppliers can provide highly accurate feed systems that practically eliminate the need for pilots in the die, many older feeds will overwork pilots beyond their original design intent due to improper setting of feeds.”
The pilot release, also known as the feed release, allows the pilots in the die to accurately position and register the strip. For the pilots to position the strip correctly, according to Ulintz, the upper feed roll must open (lift) imme- diately after the tip of the pilot enters the strip. If the feed roll opens too early, the strip could pull out of position due to the weight of the material in the feed loop between the feeder and the coil.
In addition, if the feed roll closes too soon, the feed length will appear excessively long. This holds especially true, Ulintz explains, for progressive dies that require long stock-lifter travel

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