Clearview National March 2016 - Issue 172 | Page 104

MACHINERY

The Benefits of CNC
Profile Machining
»»FOR FABRICATORS
planning to visit this year’s
FIT Show 2016 with a view to
purchasing new CNC profile
machinery, what better to be
prepared and know more about
the basics of the overall mechanics
of how the machines work
and what operations they can
perform.
Andy Bates production
support and training manager
for elumatec UK shares with
Clearview some of the basic
capabilities of CNC machining
and how they can improve
manufacturing process.
Clearview: How is a CNC
profile machining centre
controlled?
Andy Bates: The CNC profile
machining centre’s axis drives are
computer controlled, allowing
precision movements. These are
then linked to either a rack and
pinion or ball screw to transfer
the drive from the motor to
the machine. This gives precise
control of the feed rate of the
cutter. For example; when drilling
a hole a feed rate of precisly
300mm per minute may be
required.
The drives are also interlinked
so they can perform moves in
unison; if the machine is routing
a slot on the top of a profile at a
45° angle the X and Y axes will
need to move synchronously to
produce the slot. This is easy for
a computer to achieve but not
so easy for a human - if you have
operated a copy router you will
know it is impossible to make the
tool move diagonally without a
special templates.
Clearview: Can you explain a
bit more about the axes?
Andy Bates: A CNC profile
machining centre can have three,
four or five moveable axes. On a

3-axis machine these move in the
planes labelled X, Y and Z.
The X-axis moves side to side
along the length of the profile, the
Y-axis moves back and forward
across the width and the Z-axis
moves up and down the height.
The distances of these axes vary
upon the machine specification.

Clearview: How does the
tooling specification and
selection work on a CNC profile
machining centre?
Andy Bates: In simple terms,
the machine holds a number of
tools that can be driven directly
from the spindle to machine the
faces and/or ends of the profile.
The tools are driven by an
electro spindle – which looks like
an electric motor but is a lot more
complex. It allows greater control
of the speed, usually to within
a couple of RPM. The RPM of
the tool is maintained even when
cutting load or resistance is placed
on it. This consistent rotation
speed allows the machine to
perform precision operations like
tapping.
The other main feature of
the electro spindle is its ability
to locate and pick up the tools.
This means you can control and
change tooling automatically
during the machining process
via the CNC Profile Machining
Centre’s computer interface

104 » MAR 2016 » CL EARVI E W- UK . C O M

The range of tools available is
very broad and can accommodate
the processing requirments of
both fenestration and industry
products. Tools include; routers,
drills,taps and milling disks.
The data for selecting and
controlling the tools is input
into the machines software. This
includes the diameter, maximium
drilling depth and the type of
tool holder it it set in.
elumatec’s CNC machines are
controlled by an industrial grade
PC. This is similar to an office PC
and runs MS Windows but an
industrial grade PC has
greater protection
against vibration
and electrical
interference
allowing it to
operate reliably in
a manufacturing
environment.
The 4