NC lathe stops intermittently at same line in the programme

[thivanka]

There is a ECOCA SJ - 35 HT CNC (control is Fanuc Oi - TD) lathe machine. It is used to machine impellers, suction flanges of pumps etc.while it is machining a particular impeller, machine stops intermittently but it occurs always at same line in the programme ( but this problem is not occuring each and every time that programme runs). once it is stopped, the word ' alarm' is shown on one place of the display and also 'hold' word appears (important - running programme is still being displayed on one side of dispaly).
*** again programme start to works and machining happens from where it stopped when we switch on the start button on the control panel.


I want to know whether this problem is due to a problem in programming or due to any other reasons. please help me quickly

HERE IS THE PROGRAMME ( THE LINE AT WHICH PROGRAMME STOPS IS IN BOLD),
%


O0029(NSP IMPELLER MACHINING INITIAL PROGRAMME)


N1T1010
G50S400M03
G96S45
G0X190.Z150.
X147.9Z3.1
G1X142.5Z3.6F0.11
G2X54.Z13.3R500.F0.2
G0X55.Z26.6
X50.5
G1X0.F0.25
G0X55.Z26.7
Z24.7
X52.
G1X-1.1F0.2
G0Z24.8X45.5
G1Z15.1F0.2
G0X46.Z24.8
X41.5
G1Z24.1X43.35F0.16
Z15.1F0.25
X47.F0.32
X54.2F0.5
G0Z13.5
G1Z13.3F0.16
X43.35F0.23
Z15.7F0.4
G0X250.Z160.
T0M05
M01
N2T0404
G97S280M03
G0X295.Z40.
X0.2
Z-31.2
G1Z-32.3F0.04
Z-34.F0.07
Z-50.1F0.19
G0Z50.
X3.
T0M05
M01
N3T0808
G97S250M03
G0X39.7Z102.
Z40.
G1Z36.6F0.1
G0X38.Z39.
X43.
G1Z36.4F0.1
G0X40.Z50.
X44.Z99.
T0M05
M01
N4T0202
G97S250M03
G0X36.1Z117.
Z24.8
G1X35.27Z24.1F0.1
Z21.4F0.2
Z20.85F0.1
X16.4F0.16
G0Z25.
X45.Z110.
T0M05
M01
N5T1212 // Tool changer changed to under cut tool from boring tool
G97S200M03
G0X29.Z137.
X17.
Z5.5
Z1.75
G1Z1.2F0.14
X14.4Z-0.2F0.1
Z-10.95F0.115
X16.4F0.07
G1X13.7F0.4
G0Z140.
X18.
T0M05
M01
N6T0606
G97S230M03
X35.Z99.
X32.
Z-40.
G92X35.65Z-52.5F1.41
X35.85
X36.05
X36.15
X36.3
X36.5
X36.53
G0Z-37.X34.
Z99.
X230.
M01
M30
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Edit/Delete Message

[John_B]

The bold highlighting doesn't show for me, can you add quotes or something (maybe >> xyz f <<).

[sinha_nsit]

Might be due to optional stop M01.
Check the status of optional-stop switch on the MOP.

[thivanka]

@jhon B

here is the programme line where machine stops.

N5T1212 // Tool changer changed to under cut tool from boring tool

[thivanka]

what do you mean by MOP?

[newc]

Machine Operator's Panel

[mfgbydesign]

Get rid of the comment or use parens instead of slashes. might be confused with block skip by the control. Use ALL CAPS for anything in the program, including comments.
The T0's prior to the tool change may be cancelling offsets & causing the machine to think it's going overtravel. I've never seen a need for a T0 in a lathe program.
I am also not understanding why you stop the spindle (M5) prior to tool change. The machine might not move X or Z without the spindle running, and it probably wants to make a move with the new tool offset.

[MKMANU]

use parenteses get rid of the slashes../ is block skip // is probably causing the alarm

[thivanka]

// Tool changer changed to under cut tool from boring tool


this slashes and the comment doesn't exist in the real programme. that is something i added later inorder to give viewers a idea what is happening at the programme when problems comes. so those slashes and the comment cannot be the cause of the problem.

[viorel26]

Go to message screan and see what alarm appears

[John_B]

I think you may want to try a G0 in front of your toolchange line. I have a lathe that requires this, don't know why - but it does... Other than that I have no other ideas...

[Dan Fritz]

What kind of tool changer does this machine have? Does the tool change to T12, then the machine stops, or does the tool change not happen?

Something may just be putting the control into "Feed Hold" momentarilly. The Feed Hold switch is normally closed, so any loose connection in that +24v circuit will put the control into Feed Hold. You can resume from any Feed Hold condition by pressing Cycle Start again, but we need to find out why the Feed Hold is happening. Could it be a switch in the tool changer?