“It’s drag-and-drop programming for the sorting of parts,” Aronson said. “You
tell it where you want the parts stacked, and it will stack the parts there.”
The machine also has a conveyor underneath the processing table that helps
to move certain parts to a central collection spot (see Figure 4). Instead of us-
ing just one collection box, P&A Metal Fab purchased the SU- 9 rail-based sorting
bin system, comprising three large bins, roughly 3 by 4 ft., that each can be di-
vided into three individual collection points. A motorized, chain-driven assem-
bly moves the appropriate box into place to retrieve the part as the processing
is taking place. If all of the bin options are being utilized, a fabricator can have
nine different collection points for parts coming off the combination machine.
“The big difference when comparing this to the old combination machine is
that the older machine didn’t sort any parts. Everything was microtabbed onto
the skeleton,” Aronson said. “So when we came in the next day, we had two
people sorting parts and shaking them out of the skeletons. Then we had to
detab the parts.”
Instead of two part sorters, P&A Metal Fab now has only one removing parts
from the pallets stored in the tower and tagging them for various downstream
jobs. It’s still sorting, but not nearly as labor-intensive as it once was.
When a sheet is complete on the laser/punch combination machine, an unloading device moves the skeleton to a scrap table. Meanwhile, the LSR has already moved another sheet of material into the staging area and is ready to move
another sheet onto the processing table to start the process over again.
The automated storage and retrieval system and parts handling and sorting
have enabled P&A Metal Fab to run jobs unattended overnight or over a weekend, Aronson said. Sometimes parts tip up or something triggers a sensor in
the cell, which shuts down the entire system, but the control system sends out
notices about the situation to key shop floor personnel. They are then able to
take steps to figure out what tripped the sensor, correct it, and set the machine
again for unattended operation.
It should be noted that P&A Metal Fab also purchased a nitrogen generator
at the same time it brought in the new laser/punch combination machine. (For
more on the nitrogen generator, see the “Fabricating a new approach to
nitrogen generation” sidebar.) The metal fabricator had customers that demanded laser-cut parts have no oxide edges on them, so that they are in better
shape for powder coatings to adhere to those edges. This means that nitrogen
has to be used as an assist gas during laser cutting, and fiber lasers are known
to consume a lot of nitrogen as they zip around a nest. (Nitrogen is much more
expensive than oxygen. Oxygen is frequently used for laser cutting, but it also
leaves the oxide edge that many OEM customers don’t want.)
“About 95 percent of the time, we are using nitrogen from this generator,” Aronson said.
Just in Time
With the machine in place for about a year now, Aronson said that his team has
gotten “really good at using it.” That’s good timing because the shop is having
one of its best years in recent memory. In this equation, it was good that the
fabricating capability was in place before the demand overwhelmed the shop.
“We’re fortunate to have the foresight that we did. We are very busy right now.
If we didn’t have this combination machine, we would be having a tough time,”
Editor-in-Chief Dan Davis can be reached at firstname.lastname@example.org.
P&A Metal Fab Inc., 503-655-2389, www.pametal.com
Prima Power North America Inc., 847-952-6500, www.primapower.com
Parts sorting is simplified for P&A Metal Fab because certain fabricated parts are deposited into bins underneath the combination machine.