Custom Hydroforming with FDM Tooling
Hydroforming and rubber pad pressing use pressure to force sheet metal to take the form
of a mold or die. These methods can produce complex curves and shapes as well as small
undercuts. They are primarily used for low–volume manufacturing. They can also be utilized
effectively for prototype and development work, repair parts, and one–off custom parts. For
example, hydroforming and rubber pad pressing are used in the aerospace industry to form
sheet metal into airframe or engine components. In the automotive industry, they are used
to produce engine cradles, suspension components, radiator and instrument panel support
beams and engine components. Military depots produce one–off replacements for the repair
of damaged vehicles and aircraft.
Hydroforming and rubber pad pressing dies or form tools are traditionally produced using a
variety of materials and methods. Challenges with these methods include shortages of skilled
labor, long lead times due to a backlog at the Computer Numerical Control (CNC) machine,
high cost of raw materials, and high cost and lead times due to outsourcing. Stratasys 3D
Production systems can help to alleviate these problems by producing Fused Deposition
Modeling® (FDM) tools. FDM technology is an additive manufacturing process that builds
plastic parts layer by layer, using data from CAD files.
FDM tools can help companies move from tool
design to production in as little as a week. Many
FDM tools can be completed in less than 24
hours with lights–out fabrication. Switching to
FDM requires little change to current practices
and procedures yet offers significant reductions
in the time required to produce good parts.
FDM reduces the cost for die production by 50%
to 70% and reduces lead time by 60% to 80%.
There is virtually no limit to the geometries that
can be produced with FDM so it is often possible
to implement design improvements in the end
product. In fact, 3D Production Systems offer
greater cost and lead time advantages with more
complex and organically shaped parts when
compared to CNC machining.
Stratasys offers several FDM materials for its line
of 3D Production Systems that withstand the
pressures required for hydroforming including
acrylonitrile butadiene styrene (ABS) M30,
polycarbonate (PC), and ULTEM 9085. The
recommended forming pressure range for these
materials is shown in the accompanying table.
When dealing with rubber pad pressing, 3.0 inch
(76.2 mm) tall FDM dies have been successfully
cycled on 1000 ton presses using ULTEM 9085.
Materials tested over FDM form blocks include
aluminum alloys, stainless steels, titanium and
nickel-based super alloys such as Inconel. Sheet
thicknesses that have been formed successfully
range from 0.016 inch to 0.100 inch (0.41 mm to
2.54 mm). These tools have lasted hundreds of
cycles showing little to no signs of wear. In one
case, a tool lasted 600 cycles without any problems.
FDM tooling also offers a variety of other benefits. FDM tools are lighter and more ergonomic
than traditional tooling, resulting in improved safety for the tool handlers and machine
operators. Also, due to the natural porosity and lubricity of FDM, the number of cycles
required to form trapped pockets can be greatly reduced and the need to lubricate sheet
metal blanks can be eliminated. Further, the all digital process supports repeatable tool
creation without need for an outside supplier and coordination of secondary tooling such as
drill tools, trim tools and check fixtures. This makes it possible to potentially free up valuable
Pryer Technology Group (PTG) is a supplier of hydroforming presses. PTG’s Triform Hydroform
Presses incorporate a unique pressure containment system that significantly reduces the press
size without sacrificing integrity or durability. PTG evaluated FDM hydroforming form tools as
an alternative to traditional form tools to produce one–off components to replace damaged or
corroded sections of an aircraft frame. The corroded frame was digitally scanned and a CAD
model of the repaired part and desired tool stream was created. A family of the tools including
form tool, trim tool and drill tool were then manufactured with the Stratasys Fortus production
system. In working with PTG on a variety of form tools, it has been demonstrated that FDM
tools can see up to a 70% cost savings and as much as 80% cycle time savings compared to
outsourced metal CNC tool fabrication.
“We were not familiar with FDM or the
thermoplastic materials that are used in the
process,” said Scott Pryer, President of PTG.
“But after using FDM tools in our hydro forming
presses, we are quite impressed. The FDM dies
were produced in hours as opposed to the days
that are normally required. These tools withstood
up to 10,000 psi of pressure time after time.
We believe that FDM tooling is a good option
when time or traditional tooling methods are not
practical. Since the tool building time–frame is
greatly reduced, it will make part development
easier. Tool designs can be tested, modified and
retested quickly and easily.”
“Along with building the form tool, FDM has proved its value in making other accessories used
in our process such as trim tools, drill tools, forming aids, etc,” Pryer added. “When forming
down into blind recesses we typically have to use a vent hole to allow trapped air to escape.
The FDM tooling is constructed in a way that it can vent trapped air without a vent hole. The
plastic material also provides a surface lubricity that, in many cases, will eliminate the need for
How Did FDM Compare to Traditional Tooling Methods for Pryer?
4 days (80%)