31
"all of the parasitic losses, like
pumps, electronics, and hydraulic
units" that occur when the
machine isn't machining parts. He
says that studies at UC-Berkeley
show that the amount of power
being consumed for no productive
reason is on the order of 40 to
60%. In addition to which, you
have to calculate into the non-
cutting time of the machine the
overhead for the plant lighting,
HVAC, etc.
"Getting the non-running times
down to a minimum makes the
machines far more sustainable,"
he says. "So if we can use a fve-
axis machine or a mill-turn,
where we can do everything on
a single platform and the spindle
is cutting the whole time, we
can show dramatic decreases in
energy use."
He acknowledges that while people
are familiar with their computers
and smartphones going into energy-
saving "sleep mode," this is some-
thing that is just becoming part of
machine tool functionality, with
pumps turning of and electronics
powering down after a user-speci-
fed period of non-use. When,
as he points out, it is likely that
standard job shops may have just
50% spindle utilization, that sleep
mode can make a big diference
on energy use.
But in higher-volume production,
big diferences can be realized in
energy savings via small things.
Hansel points to an automatic
toolchanger for a machining
center. While a toolchange can
be made in two seconds, he says
that if they are able to reduce
that by 0.1 second, "it may
seem like nothing, but over the
course of a year in a production
environment, that adds up to a
huge amount of time that the
machine would otherwise be idle."
And wasting energy.
They're using inverter control
to vary the output of motors to
0714ADP FEATURE Machining Tools -- Digital Version.indd 31 6/17/2014 1:10:21 PM