PCAMing is a technique that allows for different length parts to be created on a web press by adjusting the speed of the tooling. It’s a perfect example of how merging mechanical and digital capabilities can yield exciting new possibilities.
Randomizing tooling creates a 30x increase in throughput
A longstanding dilemma for web operators is how to produce different length parts cost effectively. For example, the precision manufacturer Web Industries was contracted to produce a wire and cable product requiring randomized features.
Web Industries didn’t want to invest in a flat-bed die to achieve the randomizing effect. Instead, they wanted to use their rotary line. Delta ModTech, using PCAMing, was able to randomize the cut lengths in almost any repeat range centered around 100 inches.
When applied, the result was a 30x increase in throughput for Web Industries, and a very happy client. (You can review the complete case study here.)
So how was it possible? And how does PCAMing work?
What is PCAMing?
PCAM is a programmable cam function that allows you to change the speed of a tool in relation to the web using advanced servo control.
When the tooling is in contact with the web, the PCAM function will allow it to match the web speed. When the tooling is not in contact with the web, it will increase or decrease the speed in order to make up for the difference in the remaining rotation.
“You can match the speed of the web to when the die makes a cut, and specify a particular blade,” said John Schultz, a trainer at Delta ModTech.
Without PCAMing, any time you want to change the part length, you have to order a new engraved tool.
Here is an example of PCAMing in action:
An example of two lengths required for the PCAM.
How is PCAMing possible?
The flexibility of this system can be attributed to the servo motors used by Delta ModTech in its machines. “With the programmable camming software, the servo will automatically speed up or slow down, unlike other line-shaft machines,” John said.
As we explained in this article on servo motor technology, the servo differs from a conventional mechanical approach, where a machine is driven by backshafts, gears, pulleys and belts.
The interrelated nature of all those components is the opposite of a servo motor, which is powered by an electric motor and an encoder or position-sensor. Once the servo motor is in position, it will hold the position, even if external forces work against it.
The motion control software then speeds up or slows down the position of the die. “We’re changing the servo motors electronically with software, rather than mechanically,” John said.
Despite the independent nature of the servo motors, when using a sheeting die the spacing of the blades should be large enough so you’re not over-taxing the machine with abrupt speed changes.
Benefits of PCAMing
Improved flexibility as you simply program software instead of changing dies: In the past, if you wanted to change spacing of a cut or accumulate different parts on the web, you needed to change parts. With PCAMing, you have one die with multiple size blades, and you simply adjust the settings for the die station.
One die, huge cost savings: One die can feature many blades. This lowers your tooling costs, and your inventory. “With a line-shaft machine, you’re going to have racks and racks of tooling for the different repeats,” John said.
Don’t just reduce changeover — eliminate it: If you’re not replacing dies, you’re eliminating any need for mechanical changeover. In the eternal quest for quick changeover, nothing beats soft changeover. It’s the leanest of the lean.
PCAMing is an example of adapting to the Fourth Industrial Revolution
There are many line-shaft machines still in use throughout the industry, which requires tooling changes to achieve the PCAM effects. And naturally, there are other machines using servo motors besides Delta ModTech.
But the difference is how well companies have adapted to the Fourth Industrial Revolution, which is the integration of physical, digital and biological advancements. In this case, it’s how well the physical machine takes advantage of digital capabilities.
“Lots of people are using servos now, but success is dependent on how advanced their programming is,” Dave Grenwis, Marketing Manager at Delta ModTech noted. “The issue is not knowing how to program. It’s having the experience to know what the program should do.”
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