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Take Sheetmetal
Forming to a New Height
Smartly tooled
brand-new sheetmetal-fabricating
machines give an appliance maker a leg up in
productivity and in product aesthetics, thanks to
improved forming, extruding and embossing capabilities.
Pacific Energy Fireplace Products Ltd., of
Vancouver Island in Duncan, British Columbia, has been
manufacturing high-efficiency wood- and gas-fired appliances for
more than 25 years.
 Its use of unique sheetmetal forming tools
on two FINN-POWER Shear Genius (SG) cells-shear-and-punch
machines-demonstrate the ability to use full-tonnage upforming
stations with a tool larger than 3.5-in. dia. The firm purchased
its first SG in August 2003 to take the fabrication workload
from three of its aging stand-alone turret presses that it
coupled with manual shearing. That move yielded a 40-50-percent
jump in parts production. And when orders for its appliances
took off after an industry trade show late in 2004-the typical
end-of-season slowdown never materialized and the firm found
itself running 24-7 even after the holiday season. It ran to
FINN-POWER for a second SG to keep up with demand. Pacific
Energy had introduced a new line of luxury gas fireplaces that
spurred orders and pressure production capacity.
Says Trevor Gregson, Pacific Energy
production manager: “In the last two to three years we have
easily doubled in size. We have had some growing pains,
including bottlenecks in sheetmetal fabrication where we’ve had
to run day and night.”
A Shear Genius machine combines a 33-ton
20-station hydraulic turret punch press with a right-angle
shear. The turret press features programmable penetration depth,
ram speed and stroke length, and offers a work area of 60 by 100
in. The shear houses a 31.6-in. X-axis blade and a 59.64-in.
Y-axis blade, and can slice mild steel to 9 gauge and Type 304
stainless steel to 12 gauge.
Pacific Energy typically processes steel
sheet from 26 gauge to 3⁄16 in. thick. It also runs some
stainless steel to 12 gauge, as well as a bit of aluminized and
other coated steels.
Avoiding Sheet Marking
To produce a 4.125-in.-dia. knockout in
16-gauge hot-rolled steel, with high sheet traverse speeds for
all punching and sheet movements along with minimal sheet
marking, requires a fabricator to avoid using high form tools in
the turret. At Pacific Energy, this is achieved by using the
SG’s upforming system, which has a separately controlled
secondary 25-ton lower hydraulic ram that includes coining dwell
built into the upform process. The machine can be programmed to
form in either direction depending on the type of form required.
It also offers three additional forming modes: deep draw, with
built-in coining delay that finds use for embossing; mechanical
bottoming, for precision forming; and electronic stroke control.
To upform the knockouts, Pacific Energy
employs a special two-piece tool from Mate Precision Tooling,
Anoka, MN. The tool includes a custom 3.5-in. holder that allows
for assembly in the turret, and offers the flexibility to allow
use of regular 3.5-in. tooling in that station.
FINN-POWER’s upforming system allows full
tonnage throughout the punch stroke in an upward movement in the
turret. This feature provides Pacific Energy the maximum
flexibility in achieving various forming options. Unlike
conventional downforming operations, upforming means that the
die never rests higher than table level. So, when the sheet
moves it can’t crash into the tools, leading to machine
downtime, and avoids any scratches on the lower sheet surface.
This is particularly important with coated materials or
materials where cosmetic appearance is critical.
Extrusion Tools
A large 4.125-in. obround extrusion tool
used at Pacific Energy in its SG machines functions similarly to
the knockout tool.
 
The ability to produce both of these large
forms in a standard turret setup saves time by avoiding a
secondary operation. It also minimizes scratching and speeds
processing times.
To form extrusions, Pacific Energy tools
its SG machines with Mate’s Nova oblong extrusion tools.
Finished size is 1⁄2 by 4 in., to a height of 16 mm, on 17-gauge
enameling steel-very-low-carbon steel used for porcelain enamel.
It also forms extrusions on 16-gauge hot-rolled steel. The
extrusions are fabricated on heat-reflector parts to dissipate
heat through the vents.
“Initial part designs called for making
louvers,” says Gregson, “but in the enameling process, a louver
has a sharp edge that doesn’t lend itself to enameling. It will
chip on any sharp corner. So we went to the pierce and extrude
system using Mate tools, and it works very well.
“Forming up in the SG, rather than down,”
he continues, “provides a nice, even collar without the use of
shimming. It is easy to set up, and we don’t have to worry about
dragging the extrusions over the other tools, which can dull the
tools.”
An increase in material utilization also
has accompanied the SGs.
“The ability to use the edge allows us to
squeeze more parts onto the nest,” adds Gregson. “In some cases,
we’ve achieved 98.5-percent material utilization.”
A Fresh Look at Embossing
  Pacific Energy also is examining use of an
offset roller-ball tool on its SG machines for embossing.
The
Mate RollerBall includes a stiffening tool and ribbing tool in
one, avoiding the need to make a new embossing die set for every
new prototype job. The versatile turret-press tool, which can
run as quickly as 1000 in./min. on the soft enameling steel, can
be used to stiffen large sheet surfaces, create channels for
fluid flow or create aesthetic changes in the sheet surface, to
name a few other uses. It will give the company more freedom to
experiment with different embossing designs rather than having
to purchase hard tools.
Making the roller-ball tool even more
attractive is a “wheel-soft” command within the SG control that
allows the sheet to begin indexing as the tool approaches,
resulting in progressive engagement. This minimizes or
eliminates sheet marking. And, if any marks do occur, the
control sequence directs the tool to overrun the start point of
the embossment by 1 to 2 in. to smooth out the marks.
Pacific Energy creates 4.125-in-dia.
knockouts in 0.062-in. hot-rolled steel using upform stations
(tools are seen in the photo below) on its shear-and -punch
machines.
For a copy of this article, contact Tiina Alanko at (847) 781 3287 or tiina@finnpower.com
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710
Remington Road 
Volume
15 Issue 1 -
July 2005