pinch turn

[Camdude®]

i am curious about pinch turn apps. My main question is:

do you set your turrets to cut at the same "X" value or do you stagger the x value so one side cuts at a certain depth and the other tool cuts deeper. the theory being that the first tool is removing a radial value.

Or:

do you leave the value the same and double the feed rate?

[Columbo™]

You do stagger the X......You also have the shallower X turret lead in Z........

 

The two turrets remove the same amount of material.......example.......upper turret removes .100......lower turret follows the upper turret about .100 behind and removes an additional .100 making a total of .200 per pass.....

[Columbo™]

How big are the parts.......?????

 

Old boss here made us do it to a family of parts that had a head diameter of 2.5 and a shank diameter of 1.0 .......the parts were between 3 and 4 inches long........quantity of the lots were low... between 10 and 15 parts........no major time save to do the pinch turn on them smaller parts.......Longer length parts I'm sure would save some time........

[gaijin_2007]

Personally, I'm not a fan of staggering the passes when pinch turning.

It's not much but if you're using constant surface speed it's the wrong RPM for one of the tools.

I prefer to use the double feed rate method.

[GoetzInd]

quote:

---

I prefer to use the double feed rate method.

---

Agree. Plus, exact same cutting forces for smaller diameters.

 

Mike

[Greg Williams]

I use double feedrate

 

Same X pos

Same Z pos

[Guest CNC Apps Guy 1]

You don't have to trail one of the turrets either because they are opposed 180. One tool is 1/2 turn behind.

[Columbo™]

quote:

---

You don't have to trail one of the turrets either because they are opposed 180. One tool is 1/2 turn behind.

---

Makes sense James.........But our Okuma guys are telling us we have to stagger the turrets.....not sure why.....I think in the operator/programming book it says the same....Maybe turret interference when diameters get smaller.....

[Guest CNC Apps Guy 1]

Okuma's control may have trouble syncing/timing upper and lower. Nakamura can stagger or run opposite with no issues either way.

[Columbo™]

quote:

---

Okuma may have trouble syncing upper anf lower.

---

OK......maybe that was it........both of our two turret Okumas require that........no biggie.......

 

Thanks James

 

[Guest CNC Apps Guy 1]

Anytime...

[Greg Williams]

quote:

---

But our Okuma guys are telling us we have to stagger the turrets.....not sure why.....I think in the operator/programming book it says the same

---

The control can sync the turrets no problems, You can stagger or have parralel turrets for balanced cutting I do it all the time. What machine/control do you have? Are you using LAP3 or LAP4 cycles.

 

Below is a LAP4 sample from a Macturn

 

N0001 G13

N0002 G140

N0003 P0010

N0004 M216

N0005 G20 HP=4

N0006 G50 S2500

N0013 G13

N0014 G141

N0100 G13

N0101 G140

NA001

N0102 MT=00101

N0103 M321

N0104 VLMON[2]=10

N0105 G97 S696 M41 M04 P0020

N0106 G20 HP=4

N0107 TL=001001 BA=45 M603

N0108 G00 X128

N0109 Z5.4

N0110 G96 G110 S280 P0030

N0111 G85 NL001 D5 F1.4 M85 P0040

NL001 G83

N0112 G01 X20.4 Z0.2

N0113 X120

N0114 Z-76.2

N0115 G81

N0116 G00 X18.703 Z0.932 G42

N0117 G01 X24.4 Z-1.917 E1.4

N0118 Z-25.8

N0119 X58.1 E2.1

N0120 Z-49.8 E1.4

N0121 X76.2 E2.1

N0122 Z-69.8 E1.4

N0123 X100 E2.1

N0124 G03 X110.4 Z-75 K-5.2 E1.4

N0125 G01 Z-78

N0126 X122.4 E2.1

N0127 G40

N0128 G80

N0129 G00 X128

N0130 VLMON[2]=0

N0131 G97 S696 P0050

N0132 G20 HP=4

N0133 P0070

N0234 G13

N0235 P0090

N0238 G13

N0239 P0130

N0243 G13

N0244 G140

N0245 M215

N0007 G14

N0008 G140

N0009 P0010

N0010 M216

N0011 G00 X800 Z400

N0012 G50 S2500

N0015 G14

N0016 G140

N0200 G14

N0201 G140

NB001

N0202 VLMON[1]=10

N0203 G97 S696 M41 M04 P0020

N0204 G00 Z6 T001001

N0205 X128

N0206 Z5.4

N0207 G96 G110 S280 P0030

N0208 G85 NL002 D5 F1.4 M85 P0040

NL002 G83

N0209 G01 X20.4 Z0.2

N0210 X120

N0211 Z-76.2

N0212 G81

N0213 G00 X18.703 Z0.932 G42

N0214 G01 X24.4 Z-1.917 E1.4

N0215 Z-25.8

N0216 X58.1 E2.1

N0217 Z-49.8 E1.4

N0218 X76.2 E2.1

N0219 Z-69.8 E1.4

N0220 X100 E2.1

N0221 G03 X110.4 Z-75 K-5.2 E1.4

N0222 G01 Z-78

N0223 X122.4 E2.1

N0224 G40

N0225 G80

N0226 G00 X128

N0227 VLMON[1]=0

N0228 G97 S696 P0050

N0229 Z6

N0230 X800

N0231 X800 Z400 T001000

N0232 M05 P0060

N0233 M01 P0080

N0236 G14

N0237 P0090

N0240 G14

N0241 P0130

N0242 M215

N0246 G14

N0247 G140

N0248 M02

[Camdude®]

Guys ,

thanks for the input we have a twin spindle here and but nobodies tried it yet so iam going to give it a go.

[Columbo™]

quote:

---

What machine/control do you have?

---

We have two......

 

1st one...

 

LU35 with OSP7000L control

 

 

2nd one...

 

LU25 with OSP-U100L control

 

quote:

---

Are you using LAP3 or LAP4 cycles

---

Yes we are....

[Zoober]

quote:

---

thanks for the input we have a twin spindle here and but nobodies tried it yet so iam going to give it a go.

---

Camdude, these guys are talking about balanced turning. Multiple turrets cutting at the same time on one bar.

Now you mention twin spindles. Are you wanting to pull turn (similar to swiss)? or balance turn?

I have done both fairly successfully.

Stagger .02 if you want to rough/finish, and don't stagger if you want to balance turn a long shaft.

My $.02

[Greg Williams]

This one should work on an LU

 

0001 G13

N0002 P0010

N0003 G00 X800 Z1000

N0004 G50 S2000

N0100 G13

NAT01

N0101 G97 S884 M42 M03 M08 P0030

N0102 G00 X108 Z4 T010101

N0103 G96 G110 S300 P0040

N0104 G85 N0105 D3 F0.8 U0.4 W0.2 P0050

N0105 G81

N0106 G00 X35

N0107 G01 Z0 G42 E0.8 P0010

N0108 Z-30 P0020

N0109 G02 X45 Z-35 I5 P0030

N0110 G01 X56 E1.2 P0040

N0111 X60 Z-37 E0.8 P0050

N0112 Z-60 P0060

N0113 X100 E1.2 P0070

N0114 G40

N0115 G80

N0116 G97 S884 P0060

N0117 G00 X800 Z1000 T0100

N0118 M05 M09 P0070

N0005 G14

N0006 P0020

N0007 G00 X800 Z1000

N0008 G50 S2000

N0200 G14

NBT01

N0201 G97 S884 M42 M03 M08 P0030

N0202 G00 X108 Z4 T010101

N0203 G96 G110 S300 P0040

N0204 G85 N0205 D3 F0.8 U0.4 W0.2 P0050

N0205 G81

N0206 G00 X35

N0207 G01 Z0 G42 E0.8 P0010

N0208 Z-30 P0020

N0209 G02 X45 Z-35 I5 P0030

N0210 G01 X56 E1.2 P0040

N0211 X60 Z-37 E0.8 P0050

N0212 Z-60 P0060

N0213 X100 E1.2 P0070

N0214 G40

N0215 G80

N0216 G97 S884 P0060

N0217 G00 X800 Z1000 T0100

N0218 M05 M09 P0070

N0219 M02

 

Makes this

[Columbo™]

Thanks Greg.....I'll look into it and give it a try....