HSK Toolholder
( OLD)
The TSK toolholder is made with a thin wall so it can
collapse rather than force the spindle to
expand. The TSK toolholder is pulled back against a
face which means it cannot move further back into the spindle and cannot
'wobble' and become eccentric. With high clamping force against the face there
is greater torque capacity. For low speed high torque application (where
balancing is not critical anyway) a positive drive key is used.
The main benefits are;
* High speed does not change tool position.
Conventional tapers expand at high speed and tool moves back into taper - hard
to remove and changes tool reference.
* More accurate location - using the face keeps the
tool square. This is especially important with longer tools.
* HSK allows higher spindle speeds - and therefore can
require tighter balancing tolerances.
(D. Norfield, Practical Balancing of
Rotating Machinery, p.210)
(NEW / BETTER)
Machine spindles exceeding 15000r/min are currently
becoming standard and the traditional CAT steep taper design of does not
perform well at these spindle speeds.
HSK, an acronym for Hollow Short Tapper, is a
worldwide standards universal tooling system ideal for lathes and machining
centers. Features can include thru-the-tool self-sealed coolant system to
protect the taper and clamping mechanisms from internal contamination. Other
design systems include Kennametal (KM), a system that preceded HSK,
Sandvik (Capto), and Valanite (RV).
Breakout Board (About CNC)
(OLD)
No definition older.
(NEW / BETTER)
The breakout boards are
interfaces between the computer and motor controls and also other devices on
CNC machines which wanted to be controlled. These boards are using for
translating the signals to run CNC by computers. Also isolating the mother
board from electrical problems.
( Patrick Hood-Daniel,James Floyd Kelly, Build Your Own Cnc
Machine, chapter 6 )
Pendant (About CNC)
(OLD)
A pendant is a relatively small hand-held device
that the user plugs into either a USB or serial connection, allowing remote
control of the machine (obviously within the limits of the length of the cord).
Keys on the pendant are able to program or assigned various functions that are
normally executed via the keyboard. Customary remote functions typically are;
move, rapid, z touch off routine, pause, stop, file start, etc. There are
several makes and models of pendants available on the market and most require
the use of plug in software to enable their use with controller software. An example
of one these devices is the Shuttle Pro form http://contourdesign.com ; it is
even possible to use your Xbox 360 controller (with Mach3). Here again, the
user is responsible for determining which bottom on the controller gets
assigned a specific function. The pendant the author prefers does not require a
plug-in as it is a keyboard emulator and works with any controller
software. In addition you can build your own remote pendant. There are numerous
free plans and examples available on the Internet you can use. Building your
own enables you to custom design one for your specific needs
. (A. Over by, CNC Machining Handbook:
Building, Programming, and Implementation, p.80)
(NEW / BETTER)
A type of industrial control pendant, teach pendants
are the most popular robotics teaching method, and are used widely with all
types of robots, in many industries. As the robot moves within this determined
space, the various points are recorded into its memory banks and can be located
later on through subsequent playback.
There are a number of teach pendant types available,
depending on the type of application for which they will be used. If the goal
is simply to monitor and control a robotics unit, then a simple control box
style is suitable. If additional capabilities such as on the fly programming
are required; more sophisticated boxes should be used. Industrial control
pendants are equipped with switches, dials and push buttons through which data
is relayed to the robotics unit and additional monitoring systems if necessary.
(Van Drongelen Wim,Wim Van Drongelen, Signal Processing for
Neuroscientists, a Companion Volume: Advanced Topics, p.225 )
Gear Skiving
(OLD)
Skive hobbing is finish hobbing of hardened gears.
This process removes the inaccuracies in the gear flanks and profile which
occur during heat treatment. The result is improved gear accuracy. It is
possible to hob hardened gears in the range up to 63 HRC using tungsten carbide
hobs. This gear-finishing process is capable of achieving gear quality levels
of up to DIN class 6 or AGMA class 11 in standards module ranges of 1 to 6 mm.
Gear skiving has gained in recent years a considerable reputation among gear
producers and is nowadays a powerful alternative to traditional grinding and
hard hobbing.
(J. P. Davim, Machining of Hard Materials, p. 26)
(NEW / BETTER)
Gears can be finish- hobbed after heat treatment
with a carbide- tipped Azumi hob with a negative rake angle of 30 degree.
Depending on the quality required, grinding can be eliminated altogether or
reduced to one pass only. The azumi hob removes stock only from the flanks of
the teeth. The Azumi hob produces an excellent surface finish. On a work piece
of module 7 mm and a feed of 2 mm, the surface finish obtained is 1 micro
meter. The hardness of the gear can be up to 64 HRC. Azumi hobs are available
from modules 2.5 to 25 mm. The amount of stock left on the flank for skiving is
0.1- 0.3 mm for smaller module gears and 0.5 mm for larger module gears.
No coolant is used while skiving and little heat is
generated because of the excellent finish of the cutting edges of the hob and
favorable chip formation.
( Hmt,Hmt, H M T Bangalore, Production Technology ,p.386 )
Polycrystalline Cubic Boron Nitride
(OLD)
Polycrystalline
Cubic Boron Nitride is next to diamond on the hardness scale. It is used in the
manufacturing industry as a super hard abrasive tool and as a cutting tool. As
a cutting tool. PCBN is most commonly used for the machining of hardened
steels, tools steels, hard cast irons, and hard facing alloys.
(Edmund Isakov,Cutting Data For Turning of Steel, pg.
119)
(NEW / BETTER)
Polycrystalline cubic boring nitride is available in
two forms
i) Thin layers consolidated onto a cemented carbide
subsrate with a thickness less than 5 mm.
ii) Solid cubic boron nitride indexable insers. Both
particle size and the proportion and type of second phase material can be
varied for specific applications.
Consolidated blanks are usually cylindrical disc from which tool tips
of required shape can be cut: Using a laser for solid cubic boron nitride tips,
or EDM for the layered blanks.
Properties and performance of the tools depend mainly on the very hard
cubic boron nitride but the second phase plays an important role. DeBeers
reports that Amorite with a higher proportion of second phase gives a longer
tool life when used as finishing grade ( at low feeds, e.g. 0.1 mm/rev) and for
small depths of cut, while for roughing cuts optimum tool life is achieved by
tools with a low content of second phase. Considerable progress with these
materials can be expected. The process of production is expensive and as with
diamond tool tips cost in the region of 5 to 10 times the price of cemented
carbide tools.
The room temperature hardness of the polycrystalline cubic boring nitride
is given by the producers as : ‘BZN’ 35 Gpa and ‘Amborite’ 28 Gpa. As with the
hardness of diamond there is likely to be considerable difference in the values
measured by different laboratories and these differences are probably not
significant.
(Edward Moor Trent, Paul Kenneth Wright, Metal Cutting, 236 )
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