The Turning Page “the Turning Revolution”

Broaching On A CNC Lathe

One procedure witnessed on numerous turned areas today will be broaching. Traditionally
broaching have been regarded as a supplementary operations which was typically performed
on a broaching machine with unique broaching tools. Depending for the industry,
much of the form of broaching is still appearing done with this manner. For instance, in the
automotive sector, virtually all broaching is completed by substantial pricey automatic
broaching models having mainly developed broaching equipment that can certainly produce the
broaching at huge swiftness as well as quick cycles.
Of course the fact that some people will be performing over the million parts annually possesses a great deal to be able to do
with their own procedure for creation the parts. But today, even inside the automotive
sector, the importance for JIS along with reduced inventory, could rationalise accomplishing segments total about a
single machine for example the multi-axis turn/mill center. With this
equipment, the latest work could be very easily revised along with reconfigured intended for revision and
design changes. This can be exactly where mobility wins out there over speed.

Types Of Broaching.

There are generally a few a variety of broaching that may be completed on the
CNC lathe.
#1. Single position broaching on the inside and also outside size of an part.
#2. Multiple figures this kind of since hexagons or squares.
#3. Timed broaching or perhaps broached video poker machines in which require a good angular placement to
another feature for the part.
#4. Free position broaching that does not involve an angular situation to
another function n the part.
#5. Rotary Broaching
#6. Reciprocating Broaching
The sort of broaching it is advisable to do, could decide a person's tooling alternative and
method.

ROTARY BROACHING

One in the easiest along with fastest solutions to build a broached characteristic will be Rotary
or Wobble broaching. Rotary broaching may be around frequent while in the screw
machine market and is really effective, reasonably priced and also fast. It must be used extensively around the
manufacturing regarding investigating elements just like valves and also fittings along with within the aerospace
and professional medical industries. When your segments call for one particular broached polygon this is
not linked to another angular orientation as well as aspect with this component like a milled
flat or maybe drilled hole, it is usually a first choice.

A major US provider while in the manufacture associated with Rotary broaching applications and
accessories is actually Slater Tool Company out of Clinton Township, Michigan. They can be
found on the net at www.slatertools.com wherever these people number a full complement regarding rotary
tool holders, software bits, and also precise application documentation.

A simple illustration of the style of rotary broaching could be the producing of the I.D.
hex on the completed of the part. Let�s say that is usually a 5/8 hex within 12L14 steel. First issue is definitely to
determine this potential hole in order to drill, then the size and style chamfer had to come up with a good
acceptable hex. This may be driven by developing the hex dimensions simply by 1.035 to
determine the largest pilot hole to be able to be drilled.
Hex dimensions .625 x 1.035 = .646 Pilot Drill = .625 in order to .646 diameter.

To determine a suitable chamfering size, boost the hex dimensions by means of 1.1547
Hex dimension .625 x 1.1547 = .721

Next is essential to determine the actual feed with the type of fabric and broaching tool.
For the particular 12L14 steel, according to Slater Tool�s web site, we will need to broach this at
1200 RPM having a feed involving .006 i.p.r.

Here is really a simple program illustration with the rotary broach instrument programmed intended for a
Eurotech 735SLY.
O2007(ROTARY BROACH EX)
G0G40G80
N1G54T0101M64(.633 DRILL)
G0G99G97S3620X0Z.1M3M8
M58(LOAD MONITOR ON)
G1Z-.75F.016
M59(LOAD MONITOR OFF)
G0Z1.
M1
N2G54T0202M64(3.4 90 DEG. SPOT)
G0G99G97S635X0Z.1M3M8
G1Z-.3F.03
Z-.3605F.003
G4P100(DWELL)
G0Z3.
M1
N3G54T0303M64(5/8 ROTARY BROACH)
G0G99G97S1200X0Z.1M3M8
G1Z-.65F.006
G0Z.1
G28U0M5
M30
TOTAL PER TOOL
DRILL = 4.5 SEC. CHAMFER = your five SEC. BROACH = 8.5 SEC.
TOTAL CYCLE TIME = eighteen SEC.

NOTES AND TIPS FOR ROTARY BROACHING:
Special attention ought to come in for you to how very well the actual device is aligned relating with
the Rotary broach supplier. Miss-aligned tools will provide terrible tool lifetime and
surface finish.

This software is just not suited pertaining to segments in which different features including milled flats,
slots or drilled hole habits tend to be based on the unchanging situation on the polygon
produced by the Rotary broach.
Coolants and also oils will be required to crystal clear motherboards and lower scrubbing to get far better tool life
and exterior finish.

SINGLE SLOT BROACHING

When solitary or perhaps multiple broach casino wars have to be added they usually are accomplished on the
CNC lathe using a single broaching software also carbide as well as HSS. This type of
broaching necessitates the particular CNC to get C axis with regard to spindle placement plus a spindle
brake to cling the spindle steady along with firm whilst broaching. Multiple goes by are
required allowing it to possibly be made least complicated through the use of submission move development and/or macro
programming. Next we are going to study equally kinds associated with selection that will determine
what best fits the particular programmer along with the part.

Note that the majority of broached video poker machines should have a groove broach alleviation or go almost all the
way through the part. It is actually possibly not suggested for you to use this broaching procedure directly into a
blind hole or just one and not using a groove relief. Another crucial piece is usually to retract the
broaching device completely on the broached slot just before eating and also immediate traversing
back towards Z commence position.

EXAMPLE: .250 broached slot by means of .500 serious from face.

Programmed for any Eurotech 735SLY.
Sub Program.
O1444(SUB FOR .25 WIDE BROACHED SLOT)
G0X[#103](#103= .002 RADIAL DEPTH OF A PASS)
G4P100(SMALL DWELL)
G1G98Z-.5F200.(FEED BACK .5 AT two hundred INCH/MIN.)
G0X.6(CLEAR THE HOLE DIAMETER)
Z.2(RETURN TO STARTING Z)
#103=[#103+#102](UPDATE #103 TO EQUAL NEXT X VALUE FOR A PASS)
M99(REWIND)

Main Program
O1234(MAIN)
XXXX
XXXX
XXXX
(SET COMMON VARIABLES FOR BROACHING)
#101=.624(BORE DIA. LESS .001 TO MAKE EVEN # OF PASSES)
#102=.004(X DEPTH OF A SINGLE PASS)
#103=#101+#102(BORE .624 + .004 = X VALUE FOR A PASS)
N5G54T0505M64M5(.250 huge broach)
M10(C AXIS ON)
G0X.624Z.2C0.M8
M70(SPINDLE BRAKE ON)
M98P331444(CALLS SUB PROGRAM 1444 TO REPEAT 33 TIMES)
M71(BRAKE OFF)
M11(C AXIS OFF)
G0X4.Z2.
M1
XXXXXXX
XXXXXXX
XXXXXXX
M30
NOTES AND TIPS FOR SINGLE BROACHING:
The 1st. go away is X.628 (.624+.004)
The following go away is definitely X.632 (.628+.004)
Etc.
Etc.
The 33rd pass is actually X.756 (.752+.004)
X.624 Start from X.756 End = .132
.132/.004=33 passes
Often a G4 (Dwell) as well as a new increased Z start off valuation must be used prior to a commencing of each
pass to lessen almost any taper attributable to Servo Lag.
Macro Variables #100 - #199 usually are not held throughout Macro Offsets when the cutter is
powered off. If everyone need the actual macro ideals retained inside offsets when the machine
is electric off, employ #500-#999
Estimated Time to do this specific solitary broach = 12 sec.

If it is advisable to help make more of the similar broach at distinct angular positions, your
main program would likely seem like this��
O1234(MAIN)
XXXX
XXXX
XXXX
(SET COMMON VARIABLES FOR BROACHING)
#101=.624(BORE DIA. LESS .001 TO MAKE EVEN # OF PASSES)
#102=.004(X DEPTH OF A SINGLE PASS)
#103=#101+#102(BORE .624 + .004 = X VALUE FOR A PASS)
N5G54T0505M64M5(.250 broad broach)
M10(C AXIS ON)
G0X.624Z.2C0.M8(INDEX TO 0 DEGREES)
M70(SPINDLE BRAKE ON)
M98P331444(CALLS SUB PROGRAM 1444 TO REPEAT thirty-three TIMES)
M71(BRAKE OFF)
G0C90.(INDEX T0 three months DEGREES)
M70(BRAKE ON)
M98P331444(CALLS SUB PROGRAM 1444 TO REPEAT 33 TIMES)
M71(BRAKE OFF)
G0C180.(INDEX TO 180 DEGREES)
M70(SPINDLE BRAKE ON)
M98P331444(CALLS SUB PROGRAM 1444 TO REPEAT 33 TIMES)
M71(BRAKE OFF)
G0C270.(INDEX T0 270 DEGREES)
M70(BRAKE ON)
M98P331444(CALLS SUB PROGRAM 1444 TO REPEAT 33 TIMES)
M71(BRAKE OFF)
M11(C AXIS OFF)
G0X4.Z2.
M1
XXXX
XXXX
XXXX
M30

BROACHING MACRO
Another option is definitely to create a new Macro course for your broaching requirements.
The edge that will building a total Macro course is you need to use normally the one essential format
for most of ones broaching needs. Below is one of them of an broach Macro application used
for identical broached portion through our former sample.
Macro Variables �
#100 = Diameter connected with Bore to help possibly be Broached
#101 = End of Broach Slot Diameter
#102 = Broach Feed Rate
#103 = Starting Z
#104 = Ending Z
#105 = Amount of Dwell Before Cut
#106 = Depth involving Cut Per Pass
#107 = Diameter that will Clear Broach Slot
PROGRAM � 735SLY
N8 G54 T0808 M64 M5 (.250 WIDE BROACH)
#100=.624
#101=.756
#102= .200
#103= .200
#104= -.500
#105= .1
#106=.004
#107=.600
M10 (C AXIS ON)
G0 X#107 Z.5 C0 M8
M70 (BRAKE ON)
G0 Z=#103 (MOVE TO Z START)
WHILE[#101GT#100]DO1
G1G98X[#100+#106]F#102 (X VALUE FOR A PASS)
G4U#105 (DWELL)
9
Z#104 (ENDING Z)
G0 X#107 (CLEAR BROACH SLOT)
Z#103 (RETURN TO Z START)
#100=[#100+#106]
END1
#100=.624 (RESET VALUE)
G0Z.5 M71 (BRAKE OFF)
M11(C AXIS OFF)
X4. Z2.
M1(OPTIONAL STOP)
NOTES AND TIPS FOR BROACHING MACRO:
The WHILE as well as DO claims because of this Macro system are generally encouraged over the
use of any IF along with GOTO statement. An IF record necessitates some sort of GOTO of which searches
for the distinct BLOCK range directed by means of the GOTO. Because of the block
search, your digesting time can be larger as well as would certainly add to your broaching spiral time.
Example:
Instead on the WHILE and DO, many of us may possibly include used the actual IF in addition to GOTO.
IF[#101GT#100]GOTO555
This affirmation would likely give the slicer in order to BLOCK N555 and repeat for a second time until
#101 will be the same for you to or maybe under #100.
The Macro plan might need to end up being re-written with all the IF statement found at
the completion of just one broach pass.

RECIPRICATING BROACHING
High acceleration reciprocating broaching is starting to become a growing number of popular and
is the primary decision convey accomplishing a large amount of manufacturing broaching on their
CNC equipment. Today�s high speed broaching units tend to be postioned onto the turret
and utilize the survive software drive process to be able to mail the particular tool forward as well as again at more rapidly stroke
speeds as compared with can be realized by the machine�s rapid traversing.
The primary advantages in order to such type of broaching are generally �.
?? Speed (reduced circuit times)
?? Increased Tool Life
?? Less machines put on as well as Slide Working

At cerebrovascular accident rates involving about seven-hundred shots each minute, these kind of models might produce
broached video poker machines inside a next with the normal single stroke fixed broach by using improved tool
life. Since this dwell tool drive technique are driving the tool to be able to reciprocate, the actual machine
slide is still around fixed, giving included rigidity plus less wear and tear on the machines as
a whole.