Pros & Cons of Single Part CNC Programming

Single Part Programming | Time vs Material

Single Part Programming | Time vs Material

We often hear from manufacturers that they are doing single part programming.  Some do it by design.  Some do it by default.  Either way it is a process that dramatically impacts how your fabrication operation works.  Therefore, it merits a discussion to better understand what it is and how it strongly influences throughput and material efficiency outcomes. What is single part programming?

Single part programming for our purposes is the laying out of one – often large – part geometry on a single sheet of metal, then creating a tool path program to be sent to the 2D cutting equipment, i.e. laser, punch.  Quite frequently this process is preceded by a shearing operation where a  sheet is cut to the exterior part dimensions of the part.  The material is “sheared to size.”  Then the blank part is punched or cut to fit the specifications based on the single part program created previously.

To Nest or Single Part Program

The question of whether to single part program or nest really comes down to priorities – your, the department’s, or the company’s – priorities.  It is the age old question of throughput versus material.  Which is more important? Does the time expense spent programming each part individually outweigh the cost of throughput (speed of production) or material usage that may be improved through nesting?   Is time better spent in programming and/or shearing?  Does getting more products out the door mean enough increased revenue to justify the programming time? Or is the time better spent in achieving improved material efficiency?  Greater material savings outweighs the cost of the programming time. Let’s look at the pros and cons of single part programming in a little more detail. The Upside of Single Part Programming  Convenience

  • The part is so large as to be either the size of a sheet or greater than the sheet size.  There’s no need for a nest because no parts can fit on the sheet with it.

Throughput

  • Cutting the exterior dimensions of a large part would be more machine-time consuming on a CNC punch or laser than a shear.  If this is true, and there are no parts to nest with a large part, then shearing to size would maintain throughput.

The Downside of Single Part Programming Material Waste

  1. When there are enough small parts – identical parts or different – to be nested with a large part better material utilization can be achieved.
  2. When there is a large void (window, cut out) in a large part that can serve as a place for smaller parts to be nesting material waste can be minimized.
  3. When there is a sizeable remnant along the trim strip or clamp edge that can be used for nested, smaller parts more efficient nesting can be employed.

Throughput Loss

  1. When the shearing operation impedes throughput and the process can be better streamlined by cutting/punching the part in its entirety time can be saved.
  2. When the programming time necessary to create individual part programs leads to machine downtime or other production disruptions downstream processes can be more efficient.

What if material & throughput are both important?

Here’s the real challenge.  Sometimes, both material and throughput are important.  Usually most manufacturers don’t face a clear either/or decision.  Often there are conflicting priorities in the same shop. The programmers want less time-consuming work, and management has a keen eye on the scrap rate.  Or some parts lend themselves to single part programming and others do not.

The Automatic, Dynamic Solution

The solution when you want to achieve both material efficiency and throughput is to have a CAM system that is flexible enough to meet both goals – at the same time.  You need a CAM software that can minimize or eliminate the need for single part programming, and be able to do it where there is no other option.  A nesting software package should be able to cut programming time to a minimum through automation and eliminate any throughput issues. This nesting software should also be able to identify opportunities to maximize material yield. It’s a tall order.  We recommend looking to Optimation nesting software if you are one of those manufacturers that need to watch waste and control programming time and keep throughput up…or any combination thereof.

What about you? Are you doing single part programming?  How’s it working for you?  What works? What doesn’t?  Join the conversation.

Notice: This work is licensed under a BY-NC-SA. Permalink: Pros & Cons of Single Part CNC Programming

2 comments on “Pros & Cons of Single Part CNC Programming

  1. Pingback: Evaluating the Sheet Metal Nesting Process | Part 4 of 4 | Optimation Nesting Software Blog

  2. Pingback: New Nesting Process Cut Delivery from 8 Days to 8 Hours | Optimation Nesting Software Blog

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