January 2015 – An article in Modern Machine

Transcription

January 2015 – An article in Modern Machine
RAPID TRAVERSE
Machining Technology in Brief
High-Speed Spindles
Powered by
Coolant Pressure
BY DEREK KORN
uxiliary high-speed spindles offer a number
of advantages. They enable a conventional
machine tool to achieve the higher rpms that
are typically required to effectively use smalldiameter tools for semi-finishing and finishing
operations. This increases a machine’s flexibility
while saving energy and reducing wear and tear
on its main spindle. It’s also possible to achieve
faster cycle times and improve tool life by taking
high-speed machining passes.
Common versions of high-speed spindles
include electric, air turbine and mechanical
“speeder” designs. That said, Colibri Spindles,
an Israel-based spindle designer and manufacturer,
A
The Spinjet/Typhoon
auxiliary high-speed
spindles use a machine’s
through-spindle coolant delivery system to
achieve speeds ranging
from 20,000 to 50,000
rpm. This enables
conventional machine
tools to perform a range
of operations using
small-diameter tooling,
including thread milling
as shown here.
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RAPID TRAVERSE
Machining Technology in Brief
The compact high-speed spindles can be stored in
a machine’s ATC magazine when they are not being
used and installed in the main spindle like any
standard tool.
has developed a new version that uses a machine’s
through-spindle coolant delivery system to rotate
the auxiliary spindle. Its coolant-pressure-driven
high-speed spindles, distributed worldwide by
the IMC Group, are well-suited for operations
such as milling, drilling, engraving, chamfering,
thread milling and grinding using small-diameter
tools. IMC Group companies Iscar and Ingersoll
market the spindles in North America under the
names “Spinjet” and “Typhoon,” respectively.
According to Colibri, using coolant pressure
to power the spindle overcomes a number of
inflexibilities common to other types of highspeed spindles while offering lower operational
costs. The Spinjet/Typhoon spindle models are
available in 20-, 30- and 40-bar (290-, 435- and
580-psi) versions. The 20-bar spindles achieve
20,000 rpm, 30-bar spindle models can reach
30,000 or 40,000 rpm, and 40-bar models can
reach 40,000 or 50,000 rpm. The company says
tailoring machining parameters to these higher
spindle speeds can enable shops to reduce
Ingersoll, call 815-387-6600
or visit ingersoll-imc.com.
Iscar, call 877-294-7227
or visit iscarmetals.com.
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machining time by as much as 70 percent.
The compact high-speed spindles can be
stored in a machine’s ATC magazine when they
are not being used and install in the main spindle
like any standard tool. They are available for use
with a number of spindle interfaces, including ER
32 shanks, cylindrical shanks, HSK A63, CAT 40,
BT30 and 40, and Capto C5 and C6 (ISO 266231). The spindles attach to toolholder bodies via
an ER 32 collet chuck, and cutting tools install
into the spindles via an ER 11 collet chuck that
accommodates a maximum tool shank diameter
of 0.236 inch. Recommended tool diameters
range from 0.0787 to 0.1378 inch for 20,000 rpm,
0.0394 to 0.0984 inch for 30,000 rpm, and 0.0078
to 0.0591 inch for 40,000 rpm.
To determine an approximate new feed rate
for an existing operation being switched to high
speed, Colibri suggests calculating the ratio of
the auxiliary spindle speed to the original spindle
speed, and multiplying that by the original feed
rate. For example, if the existing operation used
a spindle speed of 8,000 rpm and a feed rate of
6.3 ipm, the calculation for the new feed rate using
a 30,000-rpm spindle would be:
(30,000/8,000) × 6.3 ipm = 23.6 ipm
Real-time spindle speed monitoring is possible using a compact display that connects
wirelessly to the spindle via Bluetooth. The display
can read speeds of as many as 127 spindles being
RAPID TRAVERSE
Machining Technology in Brief
used on a specific machine tool.
The spindles are available on new DMG MORI
equipment, and their design has been integrated
into SolidCAM’s iMachining software. SolidCAM
built models for spindle use, which will make it
easier to determine the proper cutting parameters,
reduce the time needed to write part programs
and shrink the learning curve.
Second Chances for Surplus Tools
BY PETER ZELINSKI
f you held your shop upside down and shook
it, how many cutting tools would fall out?
That is, apart from the tools that are in the
machines’ toolholders and ready to be used
making parts, how much excess or unneeded
tooling is sitting untouched in the tool crib or in
the drawers of tool chests? Shops routinely are
left with cutting tools for which they no longer
have a direct need because of jobs that went
away, or jobs that didn’t require all of the tooling
purchased. In fact, because excess tooling has
a way of filling small spaces, shops routinely carry
much more of this unneeded inventory than they
are aware of having.
And in a way, it makes sense to carr y this
inventory. While there are options for selling preowned tools through a secondary market (eBay
is an example), arguably there has not been an
option that is easy enough to use for a shop to
sell many varieties of tools in small quantities.
There also has been no easy way for potential
buyers to be aware of surplus tooling available
this way so they can quickly find what they need.
As a result, the shop’s best practical choice for
I
surplus tooling is to hang onto it, on the chance
that some use for it will present itself in the future.
This is the problem that Industrial Surplus
S o l u ti o n s a i m s to a d d re s s. T h i s ye a r, th e
company launched a website, toolingmarketplace.
com, which was designed by cutting tool professionals to serve as a secondary marketplace
connecting the owners and buyers of discounted
surplus tooling.
The idea seemed like an attractive solution for
machine shops with excess tooling sitting around,
says Brian Nowicki, Industrial Surplus Solutions’
CEO. But cutting tool suppliers have embraced
it, too, he says. Brand-name cutting tool OEMs
proved to be the first sellers to use the system,
and seem likely to account for most of the site’s
available tool inventory going forward. After all,
these companies have even more surplus tooling
on hand than machine shops do.
Mr. Nowicki says simplicity is the key to the
system. Buyers and sellers will only use the site
if posting tooling for sale and finding tooling to
fit a particular need are both intuitively easy to
do. And achieving simplicity, he says, is difficult.
The website organizes
cutting tools by various key details to make
the right tool easy for a
potential buyer to find.
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