Lights-out machining is one of our specialties at Polyhistor International. For the right high-volume project, it lets us keep producing parts unattended after our team has gone home. Those extended production hours mean customers receive their orders sooner, and that can be especially beneficial at high volumes.
However, not every part is a great fit to be run lights-out; some parts need more attention during machining. Before we decide on unattended production, we assess how reliably a part can be made without an operator making adjustments. Here are a few factors that help us determine whether your project is a good fit.
Lathe-Compatible Parts
At Polyhistor, we primarily use lights-out machining for lathe parts. Our lathes are specifically set up for unattended operation, with equipment such as bar feeders supplying material as production continues.
Of course, we machine mill parts during normal working hours, along with many other parts that don’t fit lights-out criteria. The factors mentioned in this article only help us determine which projects can run lights-out and which will need an operator present.
Features That Stay Stable During Machining
The best candidates are parts with predictable machining processes. Relatively straightforward geometries can help, but we also consider whether the part’s dimensions are likely to stay consistent throughout production.
Some features like thin walls can experience dimensional changes during machining, and that makes lights-out operation less feasible. These parts may require more frequent checks or adjustments to stay within tolerance, so production with operators during normal working hours is usually the better approach.
Materials That Produce Manageable Chips
Chip control is another consideration. As a lathe cuts metal, the removed material needs to break into manageable chips that can clear from the machining area.
Some materials produce long, stringy chips that can wrap around the part or tooling. Clearing those tangles requires an operator, so during an unattended overnight run, they could stop production or damage parts.
Broad material categories like aluminum or stainless steel don’t tell us whether a part is suited to lights-out machining; the specific alloy matters. For example, 303 stainless steel generally creates better chips than 304 or 316 stainless. And tooling and cutting conditions also affect chip formation, so we evaluate the material as part of our overall process.
A Final Assessment Requires Looking at the Whole Part
Even with these factors in mind, there isn’t a simple checklist that determines whether a part qualifies for lights-out machining. Its size and geometry need to be considered alongside its tolerance requirements; for instance, a feature that presents a problem on a small part may be manageable on a larger one. The material can also factor into how successfully we can machine a particular geometry.
Our team reviews the complete project to decide whether unattended machining is a reliable choice. We never want to risk scrap or interruptions that could affect your delivery schedule.
We’ll Help You Optimize for Lights-Out
If lights-out machining could help your timeline but your parts aren’t currently good candidates, we’re ready to help identify potential design changes. With our engineering background and design for manufacturing expertise, we know how to suggest helpful changes without affecting a part’s function.
For instance, one recent customer sought out our high-volume CNC machining services for a part made with 1018 steel. They were interested in lights-out machining, but 1018 can often produce stringy chips, and that makes it a poor fit for our process. We suggested switching to 12L14 steel, an option that offers better chip breaking.
That change made it possible to run the part unattended and extend production beyond normal working hours. 12L14 did have a higher upfront cost, but the production savings offset that in the end.
Let’s Review Your Next High-Volume Project
Lights-out machining can help shorten lead times for your high-volume project. Involving our team early gives us time to assess your parts and plan production around your timeline. Contact us to discuss your next project!