Manufacturing Machinery World October 2021

AEROSPACE CASE STUDY
The oil-air separator body in the main spindle collet of the ABX-80THY. It was the first 80
mm bar capacity Miyano to be installed in the UK.
devoted to the collet work for which they
were originally intended.
Another example of where the 80 mm bar
machine has introduced benefits is when
machining one of the few Andair
components the pilot actually sees, a fuel
selector fascia plate that requires a very high
surface finish, which is achieved on the
aluminium part using a diamond tipped tool.
The plate is also engraved to indicate which
tank has been selected. Previously, after
turning it from a billet, a second operation
was required on a machining centre to mill
material from the reverse and to drill four
holes.
The method of manufacture has now been
altered, whereby milling and drilling as well
as turning are carried out from bar on the
Miyano, leaving only a small operation to
clean the bore on a separate machine. Cycle
time has been reduced by at least two
minutes and an operation has been
eliminated.
In the case of another component, in fact
the first part that was made on the ABX-
80THY, all three turrets had almost an
identical amount of work to perform. Cycle
time is 2 minutes 15 seconds including
parting-off and the component comes off
finished, whereas previously the cycle was 4
minutes, plus there was a need for a second
operation, requiring extra time for both
metalcutting and inter-machine handling.
Aluminium accounts for three quarters of
throughput at the Havant factory, with a
wide range of other materials also machined
including brass, bronze, plastics, tool steel
and other steels including stainless. Batch
sizes are relatively low, normally between
100- and 500-off, so there is a lot of machine
preparation.
The Miyanos are quick to set up however,
as they have built-in tool setters and
programs are prepared off-line using an
Esprit CAM system. Typical tolerance that
needs to be held is ± 0.02 mm and Owen
declared that if it is exceeded on any
occasion, it is always the tool that is at fault,
as the machines do not move.
He concluded, "I am a big fan of Miyanos.
They are very productive, accurate machines
and have beautiful spindles that produce
excellent surface quality. I wouldn't look at
another make of lathe.
"Support from Citizen has been fantastic,
from sales to delivery, installation and
commissioning – they are absolutely
incredible."
www.citizenmachinery.co.uk
Machining area of the ABX-80THY showing the triple-turret, twin-spindle configuration.
An Andair duplex fuel selector for which
most component parts are produced on
Citizen Miyano fixed-head lathes at
Andair's Havant factory. Products are
endurance-trialled on purpose-built test rigs
and many are flown in Andair's own
aircraft before they are released.
Manufacturing Machinery World, October 2021 29