Increasing Employee Output Through Automation
Here is What We Found
in Seven Recent Shop Visits
A challenge frequently faced by successful machining facilities is opportunity that is expanding faster than the shop's workforce can expand. Even a shop that is adding people still has to do more with each employee, because employees skilled or suited for high-value machining work are challenging to find, but the chance or the need to take on more work is pressing. Removing impediments from what employees can do and expanding the amount of machining production each employee can oversee are the only ways to respond.
At Modern Machine Shop, we report on what is happening in CNC machining by visiting the manufacturers doing best at in. Our editors routinely make "shop visits" to learn how machining facilities are making use of machining technology, and today doing more with each employee is a common theme we find. Automation is a major part of this, but automation takes many forms and presents many challenges. Seven shops we have visited recently all illustrate different aspects of this. Their stories are summarized here.
The "Unattended" Effects of CNC Machine Shop Automation
Automated machining and data collection have helped this shop not only grow its business through more lights-out production, but also establish a continuous-improvement mindset that has enabled it to become more efficient in numerous areas.
- Two bar-fed Y-axis turning centers with subspindles, live tooling and parts collectors can be set up to run overnight to get as much production time as possible out of the 15.5 hours per day the shop is not staffed. Lights-out machining accounts for more than 30% of total production hours.
- Automated data collection helps identify jobs that make sense for overnight production as the shop looks to increase the percentage of annual lights-out machining hours to 50% of its total production. That amount of unattended machining time will equate to a second staffed shift at a much lower cost.
- Getting to reliable unattended machining has involved learning lessons related to coolant, chip conveying, parts collection, bar feeding, tool management, load monitoring and measurement.
Running Unattended At Night Lets Machine Shop Serve New Customers During Day
Precision Tool Technologies
Running unattended — running so it can machine through all 168 hours in the week — has enabled this shop to use hours when staff is present to deliver work that lands outside its established specialty. To achieve unattended machining, some of the biggest challenges have related to basic details such as chips and coolant.
- Successful unattended machining is the result of a system every bit as much as the result of a hardware choice. Completing that system meant solving problem after problem that might arise during production, and more: anticipating and preventing problem after problem that no person would be present to address.
- An optical liquid-level sensor enables the automated coolant-replenishment system to work. Each high-end CNC machine at Precision Tool now has a level sensor staring perpetually at the surface of the coolant in its tank. When the surface level drops too low, the sensor triggers a refill from the central coolant system.
- Now that unattended production has been shifted to nighttime, the daytime hours have to be used productively as well. Short-run jobs have to be completed and transitioned quickly, and employees have to be able to quickly obtain the resources they need to do their work during this limited window of time.
Maximizing Machines, Empowering the Machinist: The Art of Shop Floor Efficiency
Brooklyn, New York
When the Great Recession hit, the leadership for this 66-year-old machine shop decided against cutting staff. Instead, they made a series of strategic investments and decisions around five-axis machining that has allowed them to scale up the business without increasing headcount.
- Linda Tool's approach to realizing more output out of a largely fixed level of staffing — and therefore finding ways to expand the business without hiring additional skilled machine operators — ultimately meant that each machining cycle had to do more. While the company today has numerous three-and four-axis machining centers, it is realizing the highest margins on its five-axis machining centers that can attack numerous angles in the same cycle and machining program.
- Another way of letting the machining cycle do more: circle-segment tools. As an alternative to face milling, swarf milling or ballnose milling, the company uses circle-segment tools as an efficient way to machine smooth, critical surfaces.
- A high-end coordinate measuring machine situated in the middle of the shop can be used by any operator calling up the appropriate program for their part. The operator simply grabs a fixture for that part number off a nearby rack and knows exactly where to position that fixture on the table. This simplifies quality assurance — hand gaging isn't needed and the operator doesn't even have to write anything down.
CNC Apps Simplify Machine Shop Routines
Whether purchased online or made to order, custom control functions help a contract machining startup save time and avoid mistakes.
- When the shop owner has an idea for something he wishes his CNC could do, he works with the machine tool supplier to develop an app.
- To prevent data entry errors related to tool offsets, an app presents operators with an interface consisting of slider bars corresponding to offsets. Clicking “plus” and “minus” adjusts the offset by a prespecified amount.
- A distinct ringtone on the shop owner's cell phone corresponds to a CNC reporting a problem — part of a machine monitoring app that delivers CNC status information.
Small Shop Sees Big Gains from Right-Sized Automation
A three-person machine shop applies quick-change workholding and flexible robotic automation to succeed in a high-mix/low-volume production environment.
- Automating is key to a job shop remaining competitive, but a shop can start small and adjust its level of automation to future needs.
- There were concerns about running machines unattended overnight. However, a machine-monitoring system sends alerts when problems arise, and on-machine probes are used to measure cutting tools during the process, increasing accuracy and reducing scrap and rework. The shop's team can monitor a machine's status via their smartphones anytime.
- The system consisting of quick-change workholding plus a robotic loader and pallet pool allow the machining centers to realize up to 20 hours of spindle in-cycle time per day.
If At First Your CNC Machine Shop Doesn’t Succeed with Robots, Automate Again
Alexandria Industries struggled with its first robotic machining cell. However, the aluminum extrusion components manufacturer — now with more than 20 robots — discovered that by simplifying and standardizing its automation strategy, it could reap the benefits of unattended machining even for relatively low batch sizes.
- The shop uses cells consisting of infeed and outfeed parts conveyors, robots and vertical machining centers with fourth-axis rotary indexers. Within six months of installing two of these cells, they were running 24/7 at full capacity, machining as many as 30 different jobs. The company added two more identical cells, and those were soon running at full capacity, too. Today, it has six of the cells, and one operator can tend three cells at a time.
- Alexandria has since turned to collaborative robot technology to enable VMCs to machine parts that don't fit well in the existing cells. The cobots can be positioned in front of the machines to load parts through the machines’ doors (instead of a smaller side window) while operators perform other duties in the same vicinity.
- Production employees were initially leery of robots, thinking they might eventually take away jobs. However, automating the repetitive, monotonous task of loading and unloading machines has enabled the employees to grow their technical skills and focus more on problem solving. Robotic automation also makes the company more enticing to potential new hires who see they won’t be performing basic manual labor all day long. The company has had to add employees since it started adding robots.
What is the Role of Collaborative Automation in Production?
This shock absorber manufacturer has eight cobots and counting in its production facility, plus two autonomous vehicles. Here are scenes from its shop where the picture of automation is changing.
- The ability of cobots to assist with sequential processes without the need for protective fencing not only speeds production, but also saves space.
- Cobots carry out mundane tasks humans used to perform, with no reconfiguring of the machines. The resulting efficiency has allowed the company to hire more employees who perform a greater variety of higher-value work. However, in case of a cobot malfunction, a human can take over the cobot’s task rather than shutting down this operation. Cobots are not hardwired; instead, in some cases they simply push the same start button a human would otherwise push.
- Two autonomous intelligent vehicles also serve the shop. Employees deploy these vehicles on “missions” via Bluetooth or WiFi on smartphones, tablets or computers, typically for tasks such as transporting parts between stations and pulling carts of trash toward the dumpster bay.
What Shop Will We Visit Next?
Maybe yours. Contact us if your shop has a story to tell about how automation, any other metalworking technology, or even a new idea or new technique in your machining facility is succeeding and making your shop more effective.
We look forward to hearing from you!
Produced by Linneah Deighton, Editorial Intern
Compiled by Peter Zelinski, Editor-in-Chief