by Kip Hanson
Justifying robotic automation for your shop
Luke Skywalker never questioned the need for a droid. George Jetson would have been stuck doing his own laundry without Rosie the Robot. And while it’s true that Austin Powers nearly succumbed to the evil Fembots, Captain Picard would surely have lost the Enterprise without help from Data, the ship’s android.
Making parts might not be a matter of life or death, but an increasing number of shops have learned that robots make the difference between success and failure. Robots don’t take breaks or call in sick, they don’t gripe about working late and they never ask for overtime pay. Given the right circumstances, robots are a real game changer.
But what are those circumstances? Turning a few million brake rotors each year certainly qualifies, as does welding endless miles of butt joints. No one would argue that robots are an excellent solution for high production volumes and repetitive manufacturing tasks, but most of us would never consider using one for the small lot size, high mix work typical of many shops.
Mark Eddy, president of robot integrator, Gosiger Automation LLC, says robots solve two basic manufacturing problems: low machine tool utilization and a general shortage of skilled labour. “Simply put, shops need to get more out of their capital assets as well as their employees. Robots allow an employee’s expertise to be amortized across a group of machine tools rather than one, thus utilizing their knowledge in a more efficient manner.”
Say the word robot and most shop people think job cuts. In Eddy’s experience, this is not the case. “I’ve never seen a situation where a customer actually let people go after installing automation. Most shops feel very responsible to their employees, and about the only time you see downsizing due to robotics is through natural attrition, meaning it’s not always necessary to replace people when they leave the company.”
Eddy finds that the companies who apply robots are forward thinking. They’re more productive, more profitable, and they use their people to perform data analysis, job planning and other challenging tasks that robots cannot do. This makes for happier employees, more parts out the door and fewer production surprises.
Aside from increasing a shop’s productivity, robots tend to improve its quality level as well. Parts are loaded and unloaded in a consistent manner, and if the cell is so equipped, human variables are removed from secondary processes such as part washing and even deburring. And in those cases where robots perform inline inspection, there’s no chance of fat-fingering an offset or entering a plus value instead of a minus.
Automation may call for a hefty investment. While a basic robot can cost as little as $35,000 or so, integration and tooling can easily bring the final price tag to three to four times that amount. Faced with a six-figure cash outlay, many shop owners might opt for a new CNC machine instead, assuming that another spindle will produce more parts than automating an existing one. This could be a very expensive assumption.
Jeff Estes, director of Partners in THINC Technology Centers for machine tool builder Okuma America Corp., Charlotte, NC, cites a sad statistic: machine utilization in North America averages between 35-40 per cent. “The good news is that automation can double that,” he says. “At a shop rate of $85/hour, that means an additional $60K each year, without adding an operator. Not only do you make more parts per shift, but now there’s the possibility for unattended machining after hours.”
Granted, running an entire shift lights-out is a daunting task. You’ll need probing systems to check parts, tool life management and redundant tooling, broken tool detection, systems for material and chip handling, and a degree of sophistication that most shops haven’t yet achieved. But letting the machines run for an hour or two after everyone’s gone home for the night is fairly low-hanging fruit, and grabbing it can have a dramatic impact on the bottom line.
Robots eliminate human interruption, Estes explains, but the path shops must take to implement automation profoundly changes them. “Everything must be considered. The way you group products together, the way you plan jobs and do changeovers. It drives you to reduce setup time and eliminate any wasteful processes. You begin to think differently.”
A big part of this new thinking centres around workholding. Humans can compensate for a sloppy fixture, but robots can’t. High quality hydraulic or air-actuated workholding is a must with automation. Robust cutting tools are another important aspect of automating. It’s no good spending $100K on a robot if the operator has to run over every 10 minutes to change an insert or clear chips from the work area. Predictable process control is a necessary and desirable outcome on the road to successful automation.
If you’re still thinking robots are only for high volume work, think again. Gosiger Automation worked with a job shop in southern Ohio, one running production volumes of 32 pieces or less. “We helped implement touch probing, quick change tooling, automatic touch probe part measurement, and a vision equipped robot. Changeover between any two jobs, even with very dissimilar parts, is 15 minutes or less. Better yet, it largely runs unattended.”
This last part—vision systems—is what makes today’s robots so flexible. Where in the past manufacturers had to equip robots with dedicated carousels and staging areas that oriented parts in exact positions, robots are now able to see part blanks and pick them up in a manner similar to a human being.
“The customer can just lay the parts on a conveyor similar to a grocery belt. The robot uses vision to go over and pick the parts in its field of view,” Eddy says. “When it’s done processing everything, the robot advances the belt to the next batch of parts. It takes all the individual part handling and fixturing out of the equation.”
Eddy points to another customer, this one making a variety of fittings out of steel forgings. By equipping a pair of CNC lathes with vision-capable robots, they are able to run the entire family of parts with a ‘one size fits all’ part handling system. “They still have to change the lathe’s chuck jaws and a few cutting tools between jobs, but setting up the robot is a matter of calling up a new program. It’s a huge savings.”
Best of all, they didn’t spend a ton to get there. Adding a vision option to a robot might cost less than $10,000, although Eddy admits this figure is very application specific. Vision capable or not, robots can have a profound effect on a shop’s productivity.
Both Gosiger and Okuma agree that shops need to look at, and in many cases, streamline every part of the manufacturing process before considering automation. Those who do so realize improved part quality, meaningful productivity increases and a short return on investment, often two years or less. Maybe it’s time you make room for robots. SMT
Kip Hanson is a contributing editor. [email protected]