3D-Rotary Laser Shortens
Lead Times at Rough Bros.
Opened in 1932, Rough
Brothers, Inc. of Cincinnati, Ohio manufactures greenhouses, garden centers and
conservatories. The company performs in-house fabrication of steel tubing and aluminum
beams that make up the framework of these structures and until recently, performed
most of the processing steps manually. In June of 2003, the company installed a
4000w laser cutting system that automatically loads, feeds, laser cuts and unloads
mill-length tube and structural (Mazak's Fabrigear-150). Richard Reilly, President,
discusses two parts that are
now being laser cut and how the laser has helped them
achieve significant time savings and flexibility in design.
What is the part
in the left photo?
It's a purlin, the
post that runs from the ground to the A-frame truss that supports the roof. The
part can be 10- 16' tall. We make it by cutting a series of holes, slots and notches
into an aluminum I-beam. In addition to I-beam, we also fabricate aluminum T-stock
to make the A-frame truss.
Before the rotary
laser, how were you manufacturing these beams?
Most of it was done
manually. Depending on the piece, it could take seven to nine steps. First, we'd
square off the end. Then we'd lay off—basically with a tape measure and a pencil—all
the different holes, notches and slots that we would fabricate into the material.
If a notch or slot was at the end of a piece, we'd use a punch press, which would
save us some time. Next, we'd manually drill or route out the holes or slots in
the middle of the piece and then we'd have to notch or cut the middle. Finally,
we'd end-cut the other end. It was a process that could take 45-60 minutes, so it
was very time consuming. This was one of our main motivations for installing the
laser.
How have you been
processing the parts with the laser?
We download the program
to the rotary laser, the laser processes the material and in less than 10 minutes,
we have the finished piece.
We've gone from nine steps to one, and we do processing
like this every day, all day long.
What is this
second part?
It's an aluminum
angle connector. It used to take three steps. First, we'd cut the tube to length
with a bandsaw. Next, we'd lay off the holes. Then we'd hand drill one hole at a
time, using a separate jig for each hole. There are nine holes.
How are you making
the part with the laser?
Now we do it in one
setup. No jigs. It's been a lot faster. We used to make 150 in three hours. Now
we make 295. The laser has doubled production.
Does laser quality
make a significant difference in your operations?
The tolerances we
get from laser cutting have been much tighter than what we were getting from manual
processing. And, because the dimensional accuracy is better, it's been easier to
put the parts together when we weld or assemble them in the factory. It also saves
time when we are erecting the structures in the field.
As to edge quality,
aluminum is a challenge to lasers because of its reflectivity. Additionally, each
aluminum batch is different, which means with each new batch we have to readjust
our cut conditions. Despite these challenges, we've been able to consistently meet
the specs of our jobs, and that's without buying any coated or special stock.
Are these two parts
standard in all of your greenhouses?
We do have some standard
fabrication details, such as end details, but most of our work is made to order.
The placement and size of the holes, notches and slots vary depending on the design
of the structure. That's why before we installed the rotary laser, we needed to
measure everything out each time. If the part was only going to be used once, it
didn't make sense to create a template. The laser allows
us the flexibility to process
any part one time without slowing down production. We don't need to worry about finding and changing the bits to go from drilling a 1/2" hole to a 5/8" hole. We
just do it.
In addition to flexibility
of production, it also gives us flexibility in our design, which is invaluable.
Even though we were doing it by hand before, the tools limited the design. If
we had
to make a certain type of slot, we needed a certain type of bit. If we didn't
have that bit, we'd have to delay the fabrication until the bit was delivered. Or
worse, maybe the bit didn't exist, and fabrication of the slot wasn't possible.
Now, we can put any
size or type of hole, notch or slot anywhere we want on the entire length of any
piece we want. Plus, the laser's 6-axis capabilities allow us to make beveled or
counter-sunk holes–another reason we installed this laser.
It's a real advantage
to be able to design a slot without having to worry if we have the tool or if the
tool exists. As long as we can draw it on the computer, we can cut it on the laser.
We have a whole different level of flexibility in terms of what we do and how quickly
we can make it happen.
What other advantages
does the laser offer?
Because we can respond quicker,
we've been able to shorten lead times. Our peak month is October, because customers
need their greenhouses up before winter.
With the laser, we've cut down lead times,
so we can meet the quick turnarounds our customers want even during our busiest
season. |