Please enlighten me on pinch turning in a ZL-203

[Letter Buck]

Hello Everyone,
I thought I would throw this out there and get some feedback. I am using a Mori Seiki ZL-203 I need to pinch turn a peice of 4.25'' 1018 down to .625. I was thinking of using a canned cycle for each turret with different start points on the Z, then use wait codes to time it. Am I on the right track? I assume the second turret would have a DOC of twice that of the first turret?

Thanks in advance. This site is a great tool!

[WOLOG]

If I am correct, the depth of turret 2 is the same as turret 1. Your feed rates are doubled due to the fact you are only cutting half of the part. What control do you have on this machine? There should be a Capps function for pinch turning. check that out and I will see what I can find out

[Letter Buck]

If I am correct, the depth of turret 2 is the same as turret 1. Your feed rates are doubled due to the fact you are only cutting half of the part. What control do you have on this machine? There should be a Capps function for pinch turning. check that out and I will see what I can find out

I think what you are referring to is "balance turning" which actually has a G code for it. Mainly used for work pieces that arelong and prone to chatter. Using that, your upper and lower need to be dead on with each other. (From what I have read anyways)

I will look at the control on Monday.

[WOLOG]

http://www.feature-cam.co.uk/html/bo...ti_turret.html

Check this out. I just found this while looking for more info. Hope this helps.

[Gil F]

If you link up both turrets with a M-Code then follow your rapid moves with a G68 on Fanuc controls the turrets will follow the exact path. I usually keep my Z,s in the exact position and try to use identical tools although I have tried using a different insert (finisher same radius different style) and have had sucess. Hope this helps.

GF

[fordav11]

Wow a twin turret question. I'm in heaven :-D

I've been programming a 15TTF ZL35 for many years.

There is an option (not free) that gives automatic generation of balance cutting code in the FAPT/CAPS.

If you don't have that it's simple to align each tool then rough a part down in half the time using some simple code but generally to give full control it needs to be written long-hand. Do something like this... (material dia 100mm taking 5mm cuts)

Top Turret Program                     Bottom Turret Program
G00 X95.0 Z2.0                         G00 X90.0 Z2.0
M100                                   M100
G1 Z-500.0 F0.4                        G4 U0.5
X100.0                                 G1 Z-500.0 F0.4
G00 Z2.0                               X95.0
X85.0                                  G00 Z2.0
M101                                   X80.0
                                       M101

etc etc.....

Any M-code from M100 upwards tells the control to wait until it gets to the same M-code on the other turret. Then once they are aligned with the M-codes both turrets will go.

To do it in FAPT, program the part once with the real material stock size, generate the program then go back in and set the material size 10mm bigger then generate it again. Then manually merge the two programs taking alternating cuts. It's not that difficult and the time saved in rough machining makes up for it.

Or just pay and get the Balance Cutting Option :-)
It cost us about $10000 15 years ago. It paid for itself on the 1st job we did.

[Gil F]

Long hand is not needed if your machine has a G71 function. It is much easier and less programming. I do it on Doosan TT's all the time on shaft's without using a center at a 6 to 1 ratio. G68 is the sync code.

[fordav11]

ah interesting. Can you post a small example? I looked up G68 and it was some kind of milling rotate function? All the controls I've used don't have G68 so it has to be done long-hand in that case :-)
also which control is it? Just wondering when that function was added. I'm guessing at Fanuc 18-series or later?