TOOLING ADDITIVE MANUFACTURING SUPPORTS INNOVATIVE CUTTING TOOL DESIGN & PRODUCTION
A fi nished
cutter, made
with the
critical help
of Guhring’s
Metal X 3D
printer
tool; they are life-size and cost very little.
Once a tool has been accepted as a
viable solution, the design can be veri ed by
printing it in metal. The PCD cutting tips are
brazed into place and it’s then attached to a
standard holder, so the team can check
coolant direction and perform usability trials.
Moving forward, all new special tools will be
veri ed by using some sort of 3D printing.
One of the most important features in
any cutting tool is the delivery of coolant and
cutting uids directly to the tips. This has a
direct correlation with tip life and thus the
number of passes the tool can make.
Continues Pearce: “Our aim is to
increase the period between tip
regrinds, this is one of the major
requests from our customers. We now
have tools out on test that have
directional apertures, which are
aimed exactly at the area where the
tip contacts the part. The team here
are really excited about the
potential this gives us. We can
print any aperture we need and
route the coolant pathways
anywhere through the body.”
These techniques will be also
be used to help with swarf
evacuation too, which is
another recurring challenge.
The rst tool created on the
A part in
progress within a
Metal X 3D printer
Metal X, a milling cutter, was very
important to the veri cation
process. Milling cutters operate in harsh
environments, so the team at Guhring set
out a rigorous test plan for the printed tool
bodies. Initially, a tool was manufactured
with the geometry of a reamer, to accept
vertical loads and make small cuts. Testing
took place in the Birmingham Technical
Academy and the tool passed with ying
colours. Some small modi cations were
made to the tip geometry and the team then
tested some cuts with an off-centre load, to
simulate milling. Once again, the tool
passed the test.
The team at Guhring has now moved on
to create other milling tools, which have also
performed well under load. Guhring’s ability
to create complex geometry has been a real
bonus and designs are becoming more
imaginative with each tool produced. Pearce
again: “We are working with one particular
customer to test a new milling tool concept
in a head-to-head comparison. This tool has
been designed to give an ultra-high surface
nish on castings. The data
coming back shows our
printed tools are
performing equally as
well under high speed
and off-centre loads. We’ll
use this data to further
improve our special tools
each time we receive it.”
As regards general
bene ts gained, these are
summed up as: 25% saving in
cost; 75% time saving; 60%
weight reduction; design
freedom; new applications; and
longer tool life.
Other companies in the
Guhring group have also actively
taken part in the new initiative –
tools have been shipped around Europe and
the orders are still coming in. Guhring UK
has a growing list of happy customers in and
outside of the group, it reports.
Guhring has successfully utilised heatshrink,
hydraulic chuck, steerable
attachment and mono-block designs so far.
Once the tool bodies have been printed,
they go on to be washed and then sintered
in house using Markforged-supplied
equipment. Tools are nished using
conventional methods, such as grinding,
brazing the tips in place and wire EDM
machining the tips to the correct geometry.
After the manufacturing process is
nished, every tool is inspected and
balanced before it is packaged and
dispatched to the customer. Guhring
engineers often attend the initial cutting
trials at customer premises.
Lead times on PCD cutting tools have
been dramatically reduced by the addition of
a Metal X into the production process. It is
also now possible for Guhring to deliver low
volumes cost effectively.
The management team openly admit that
they’ve only just scratched the surface of
what they’d like to achieve. Many of them
have visions of making ultra-special tools
that no one has attempted before, with
geometry that can only be 3D printed. The
journey has only just begun for the
company.
Getting rid of the swarf headache
Swarf is a major headache inside nished components and companies spend thousands
of pounds on different solutions to remove it after the machining process. Guhring thought
about this challenge somewhat differently. Using its Metal X printer, the company has
used an in-house design to stop the problem happening in the rst place. It is now
possible to produce, cost effectively and in low numbers, special tools that ‘eject’ the
swarf out of the main tool body and not down inside the part. The complex geometry
means that coolant pathways that were once impossible to produce can now be created
inside the tool body as an integral part of the manufacturing process.
40 www.machinery.co.uk @MachineryTweets March 2020
/www.machinery.co.uk