Page 32 - MetalForming February 2017

Best Practices to
Optimize Nesting
Efficiency
Effective nesting for CNC punching and cutting requires careful consideration of numerous factors, including fabrication requirements such as collision avoidance and clamp management, and order sequencing and kitting. Follow these best practices to develop an effective sheetmetal- nesting strategy.
BY BRAD F. KUVIN, EDITORIAL DIRECTOR
Nesting is complex—make no mistake about it. Merely solving the puzzle of placing parts onto sheets to optimize material use is chal- lenging enough; add in production requirements—producing the right parts at the right time to manage material flow through the shop—and the job becomes significantly more difficult. There’s so much to consider, and the list of requirements continues to grow as job shops battle to hold off the chaos that’s created as they take on new cus- tomers, new orders, smaller order quan- tities, shorter delivery cycles, greater mix of material types and thickness, etc.
To help manage the chaos, job-shop sheetmetal fabricators increasingly are turning to state-of-the-art nesting pro- grams, to get the quantities right, optimize machine use and ensure efficient material flow through the plant, and much more.
“Ensuring minimal and efficient tool
changes, avoiding collisions during processing, managing clamping—it’s a challenging job,” says Michael Lundy, president of nesting-software provider Optimation, Blue Springs, MO, ”but one that becomes increasingly impor- tant to fabricators. Most fabricators find that manual nesting no longer suf- fices. One option is to invest in software for static nesting, so they can reuse existing nests to support production of previously run parts. But what hap- pens when orders for ‘hot’ parts come in and you need to interrupt the sta- tus-quo on the floor? Managing pro- duction in this scenario requires a dynamic approach to nesting.
“Another consideration,” Lundy continues, “is the ability with dynamic nesting to create nests that include parts belonging to different orders— this can allow a fabricator to gain mate- rial essentially for free in terms of mate-
JIT nesting differs from traditional dynamic batch nest- ing in that it allows a fabricator to make adjustments to nests from one cycle to the next, by not ever building a batch nest. Instead, the nesting software allows the fabricator to automatically gen- erate and deliver the next nest to the machine (a laser or turret press, for example) just before it finishes its current nest.
rial efficiency. Also, static nesting requires fabricators to use multiple sheet sizes in efforts to optimize mate- rial use, or to shear sheets to size, which increases raw-material costs. With dynamic nesting, combining parts from multiple runs allows shops to stan- dardize on one or two blank sizes.“
Handling ‘Hot’ Parts
Lundy, commenting on a blog resid- ing on the Optimation website titled, “8 Nesting Best Practices to Gain Pro- ductivity,” stresses the importance of dynamic batch nesting, so that fabri- cators can seamlessly and efficiently adjust their nests on the fly, during a shift. One best practice noted in the blog: Automatic batch nesting allows a fabricator to develop, just in time, optimal nests that consider the real- world manufacturing environment with all of its competing priorities,
30 MetalForming/February 2017
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