Long threads on swiss

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10-27-2012, 03:10 AM
ChrisW

Long threads on swiss

Is it possible or not to make a single point thread longer then the guide bushing without mismatch on middle of thread.

Machine STAR SA-12 with sub and a axis
FANUC 18i-T

Cut thread for example :

#10-32 2a

thread length 2."

material 303 ss

Do you know a way to lead-in in the middle of thread

Tried G76

First G76 starts before Z-0.0625
end Z0.4375

Second G76 starts at Z0.375
end Z0.875

and continue till 2"
--------------------------------------
Tried G32

First line G32 lead in \
second line G32 feed ______
Third line G32 feed out /

Is there a parameter that controls G76 cycle to lead in in correct spot

Thanks
10-27-2012, 03:27 AM
txcncman

Every machine will probably be a bit different. You just have to figure out how much the mismatch is and correct for it in the programming. I would recommend G32 so you can ramp into the thread as you indicated to make a smoother transition.
10-27-2012, 04:14 AM
ChrisW

:)

Thanks
10-27-2012, 04:30 AM
txcncman

I actually have accomplished this, not on swiss though. I did it by hand feeding out and using the tool tip to position the thread at a needed Z location. I was able to run a 1/4"-20 thread on 304 stainless more than 2-1/2" long without using a tail stock on 3 pull outs. I think it was for some kind of adjustment for blood bag agitation machine for use in blood transfusions.
10-27-2012, 05:24 AM
txcncman

Additional thought. If your machine has live tooling and C axis and you can find the appropriate profile milling tool, mill the thread in a single pass.
10-27-2012, 06:52 AM
MikeMc

We do this in our Citizen L20s all the time. G32 is the command.
10-27-2012, 02:38 PM
ChrisW

SAMPLE CODE

Can you post sample code that you are running on your machines.

Thanks

Quote:

Originally Posted by MikeMc

We do this in our Citizen L20s all the time. G32 is the command.
10-27-2012, 04:43 PM
MikeMc

Sure............here is the code for the first pass:

T500(DCMT 3-0-SM)
M3S1=3000
G0X0.3365Z0.T5
G1X0.2965F0.0014
X-0.016
X-0.056
X0.132
X0.193Z0.035
G1Z.36
X.37W.092
G0X.412T0

M92
T300(ISCAR 24 THREAD)
G97M3S1=2000
G4U1.0
G99G0X.412Z-.1Y0T37
X0.28Z-.1
G32X.18Z-.01666F.04167
Z.33
U.1W.05
G0X.274Z-.1
G32X.174Z-.01666F.04167
Z.33
U.1W.05
G0X.269Z-.1
G32X.169Z-.01666F.04167
Z.33
U.1W.05
G0X.264Z-.1
G32X.164Z-.01666F.04167
Z.33
U.1W.05
G0X.26Z-.1
G32X.160Z-.01666F.04167
Z.33
U.1W.05
G0X.256Z-.1
X.156
G32X.156Z-.01666F.04167
Z.33
U.1W.05
G0X.254Z-.1
G32X.154Z-.01666F.04167
Z.33
U.1W.05
G0X.252Z-.1
G32X.152Z-.01666F.04167
Z.33
U.1W.05
G0X.252Z-.1
G32X.152Z-.01666F.04167
Z.33
U.1W.05
G0X.412W-.2T0
M93
10-27-2012, 04:44 PM
MikeMc

...............and here is the second pass:

T500(DCMT 3-0-SM)
M3S1=3000
G0X0.3365Z.3T5
G1X.193F.001
G1Z.67
X.37W.092
G0X.412T0

M92
T300(ISCAR 24 THREAD)
G97M3S1=2000
G4U1.0
G99G0X.412Z.15002Y0T38
X.28
G32X.18Z.23336F.04167
Z.64
U.1W.05
G0X.274Z.15002
G32X.174Z.23336F.04167
Z.64
U.1W.05
G0X.269Z.15002
G32X.169Z.23336F.04167
Z.64
U.1W.05
G0X.264Z.15002
G32X.164Z.23336F.04167
Z.64
U.1W.05
G0X.260Z.15002
G32X.160Z.23336F.04167
Z.64
U.1W.05
G0X.256Z.15002
G32X.156Z.23336F.04167
Z.64
U.1W.05
G0X.254Z.15002
G32X.154Z.23336F.04167
Z.64
U.1W.05
G0X.252Z.15002
G32X.152Z.23336F.04167
Z.64
U.1W.05
G0X.252Z.15002
G32X.152Z.23336F.04167
Z.64
U.1W.05
G0X.412W-.2T0
M93
10-27-2012, 04:47 PM
MikeMc

We do this 5 or 6 times to get the length entire length of the part. This is a 10-24 thread, and a 12-24, or 10-32 is completely different of course, but this should give you the basic idea.
10-27-2012, 07:59 PM
ChrisW

Program

Thanks
10-31-2012, 05:03 PM
ChrisW

1 Attachment(s)

1 st try

First try no luck.
10-31-2012, 06:23 PM
txcncman

Looks like you need to move the Z start point about 0.020". Can't tell which direction though because you did not indicate the leading surface.
10-31-2012, 08:59 PM
Babij

I have never done that, but nice to know it works if it ever comes up.
Thanks for the info!

I do a lot of G32 threads on my STAR. I use macros to save all that code writing.

Try this out if it's not too crazy for you all:

#531=.250(STOCK DIA.) I always use this macro at the top of my programs.

N50(THREAD ROUTINE)
#1=.210(START DIA)
#2=.004(PECK)
#3=.1508(MINOR DIA.)
#4=2(# OF FINISH PASSES)
T400(THINBIT STTD)
/M25
G97S1000M3
G0X[#531+.02]Z-.05T4
#33=0
N51
G0X[#1+.05]
G32U-.05W.0143F.03125
Z.5
U.05W.025
G0U.075
Z-.05
#1=#1-#2
IF[#1GT#3]GOTO51
IF[#1LE#3]THEN#1=#3
#33=#33+1
IF[#33LT#4]GOTO51
G0X1.
Z-.05T0
M1

Now for a deburr pass after turning the thread again simply
change #1 to equal the minor dia(or a few tenths larger) and
you will only get the number of passes set by #4.

You should be able to use this with what ever Z #'s you need to make your long threads.

It helps(cycle time) to run this as a sub program if you have a really long main program.
12-12-2012, 12:16 PM
thurminator

Does your machine have tools that you can bring up to guide bushing while threading? If so have you tried making a custom support and putting it in that tool location to support the workpiece when it is hanging out of the guide bushing a considerable amount?
01-22-2013, 05:56 PM
carmstrongls1

If the cycel time is not a huge concern then use G650 commands to support the thread with the sub spindle. If you do this it doesn't matter how long the thread is as long as it can be grabbed in one single chucking amount. wait... Is this a citizen machine?

L-20 and A32 I use G32

A20 machine G650

G650- Machining mode change to superimpose Z2 on to Z1. G650 will queue
with both lines $1-$2 then with M130, make Z2 follow Z1.
Example -when we pick up a part and chamfer we while we have the
back spindle collet closed on the part. Also if we are using Z2
as a work support.
Also Automaticly $1-G99 is for S1 and $2-G99 is for S2.

Note- Any shift, "G50W-.125", on Z1 must be canceled, "G50W.125", before
G650 or G650 won't find the face of the part!

G650 G650
G0 Z-.1(bring Z2 to Z1-.1)
!2L650 G1Z1.F.05(feed over)

G50W-.125 M15(close collet)
(moving Z1) !1L650(let $1 continue)
"
G1X-.1F.001
G600 G600(bring Z2 back)
G50W.125 M25
S1=1500
M7
G0X-.1Z-.005T0
M56
G999 G999
N999 N999
M2 M2
M99 M99
01-22-2013, 06:02 PM
carmstrongls1

that didn't split correctly $1 an $2

[QUOTE=carmstrongls1;1226119]If the cycel time is not a huge concern then use G650 commands to support the thread with the sub spindle. If you do this it doesn't matter how long the thread is as long as it can be grabbed in one single chucking amount. wait... Is this a citizen machine?

L-20 and A32 I use G32

A20 machine G650

G650- Machining mode change to superimpose Z2 on to Z1. G650 will queue
with both lines $1-$2 then with M130, make Z2 follow Z1.
Example -when we pick up a part and chamfer we while we have the
back spindle collet closed on the part. Also if we are using Z2
as a work support.
Also Automaticly $1-G99 is for S1 and $2-G99 is for S2.

Note- Any shift, "G50W-.125", on Z1 must be canceled, "G50W.125", before
G650 or G650 won't find the face of the part!

$1
G650
!2L650
G50W-.125
(moving Z1)
G1X-.1F.001
G600
G50W.125 S1=1500
M7
G0X-.1Z-.005T0
M56
G999
N999
M2
M99

$2
G650
G0 Z-.1(bring Z2 to Z1-.1)
G1Z1.F.05(feed over)
M15(close collet)
!1L650(let $1 continue)
G600(bring Z2 back)
M25
G999
N999
M2
M99
01-22-2013, 06:06 PM
MetalZilla

G32 is the way to go. I did a job that had a 3.0" long 5/16 thread and was able to get in 3 bar feeds and continous threading. was a pain to get it just right though.