From a design perspective, additive
manufacturing is extending the realms of
what is possible. As McKinlay states: “Putting
five cutting edges on a 21.7 mm diameter
Woodruff tool with a solid carbide body would
create significant manufacturing challenges.
The main benefits of printed tools are we can
produce multiple designs very quickly, in this
instance evolving from a three-flute to a fiveflute
tool in a matter of weeks.
“The cost-saving comes from the reduced
production time to make the printed tools
compared to solid body tools, something we
can pass on to the customer. Another benefit
with the printed tool is it can be re-tipped.
This reduces the cost of the tool further, as
the body can be re-used sometimes, whereas
the solid carbide tool is disposed of.”
3D-PRINTED PRESS BRAKE TOOLING
Away from metalcutting, press brake tooling
can also be 3D-printed, most suitably when
complex, non-standard tooling is required.
Stratasys (Laser Lines, www.is.gd/elobap )
details its findings in this area in a white
paper (Additive Manufacturing for Custom
Metal Form Tooling). These are plastic tools
but are said by Stratasys to be good for
volumes up to 1,000 parts.
Traditional press brake tooling is
Air gap 4 contours
45" Raster Angle 70" Raster Angle
The printing raster pattern should not run parallel to the contoured outer surface
machined from common tool steels such as
A2, D2 or 4140 and is purchased in standard
geometries ‘off the shelf’ from several
manufactures, such as Wilson, Wila and
Mate. But when a custom tool is needed,
cost and lead time increase drastically.
Any FDM (Fused Deposition Modelling)
material can be used for metalforming
applications but Stratasys recommends FDM
Nylon 12CF, polycarbonate (PC), ULTEM 1010
resin or ULTEM 9085 resin, as they all offer
high compression strength.
Tooling considered appropriate for
3D-printing is that employed to produce offset
bends, which are primarily used to create
additional stiffness in a part or create an
offset to allow for a lap joint to mate two
parts; ribs, used to add stiffness, with
common shapes being V, hat and round; plus
dimples/flares, used in the aerospace and
automotive industries to restore rigidity
around a weight-reducing cut-out area.
Offset tooling is the main example
detailed. The radii of the two bends are
recommended to be twice that of material
thickness to reduce excess tool wear. A
raster pattern infill with four contour passes
around that to produce a smooth surface was
employed. And the direction of raster pattern
paths should not be parallel but at an angle
to the contour paths, so as to reduce air gap
between the contour paths and infill.
Results when bending 16 gauge (1.62
mm) 5052 aluminium sheet on a 60 ton
press, showed both angle and offset
indicating little variation up to 100 units
across three sets of tooling, one each from
ULTEM 1010 resin, Nylon12 CF and PC.
A second test was undertaken for 16
gauge cold-rolled steel using a Nylon 12CF
tool. The tool was cycled 250 times at a
forming pressure of 90 kN. Again, the tool did
not see significant wear, bar the radius, which
flattened a little. The tool radius figure at
outset was 3.2 mm and became 3.6 mm, but
dimensionally accurate formed parts were still
produced, Stratasys confirms.
The per-length rating of the tools is around
0.8-1.2 kN/mm (2-3 tons/inch) for maximum
loading conditions and this general rule of
thumb can be used for similar style tools
printed with PC, FDM Nylon 12CF or ULTEM
1010 resin.
Maximum sheet thicknesses are put at up
to 2 mm for steel and stainless steel, and up
to 3 mm for aluminium. ■
TOOLING 3D-PRINTED BENEFITS
Industry & product news in brief
■ BIG Kaiser’s new EWA fully automatic fine boring tool has won the ‘production
performance’ category in the French Global Industry Awards 2020 organised to run alongside
Paris event ‘Global Industry exhibition’. www.is.gd/olujux
■ Dormer Pramet is set to acquire India-based Miranda Tools, a manufacturer of high-speed
steel (HSS) and solid carbide cutting tools, subject to conditions. www.is.gd/umoduk
■ The Komet KUB Centron drilling tool, previously only available to order as semi-standard
tools, is now available ex-stock across the range. www.is.gd/oqumod
■ Cutting tool expert Sandvik Coromant has launched a new online application training offer
to share knowledge and best practices for metalcutting operations. The eight-part programme
has been released online and is accessible via the Sandvik Coromant website.
www.is.gd/junuzu
■ Kennametal’s HPX next-generation high-performance drill is for steel applications and
“sets the bar for tool life and productivity”, the company claims. www.is.gd/ecibig
■ Kyocera has added the KPK parting-off series and the MFWN Mini series milling cutters to
its line of products. www.is.gd/rocuco
■ Quickgrind’s Mirage Super range of solid carbide end-mills is designed for a multitude of
applications in a wide range of materials. www.is.gd/exulot
■ Mapal’s OptiMill-3D series is a new programme of solid carbide milling cutters specially
developed for the tool and mouldmaking industry. www.is.gd/ogovuw
■ Swiss tool manufacturer Mikron Tool (Floyd Automatic Tooling) has added a version of its
plunge-mill CrazyMill Cool P&S, making it suitable for even deeper machining operations.
www.is.gd/eduyiy
Three different 3D-printing
materials deliver similar results
26 September 2020 | www.machinery.co.uk | MachineryMagazine | @MachineryTweets
/elobap
/olujux
/umoduk
/oqumod
/junuzu
/ecibig
/rocuco
/exulot
/ogovuw
/eduyiy
/www.machinery.co.uk