Fanuc OT-C

[mroy0404]

Hi Guys



I have a problem with a Daewoo Puma 8S with a Fanuc OT-C control, I have been trying to thread on this for some time, every time that I have tried the tool will not follow the same path twice. The RPM shows on the screen so I think the encoder is good. Is there some parameter that controls when this tool should start in the right timing.



Thanks for your time and help, I really need it this has been on going for months.



Mike Roy In Canada

[Al_The_Man]

You need to make sure that there is no backlash in both the Z axis and the encoder gear train to the spindle.
Al.

[mroy0404]

Hey Al

I Have looked at this and can not find any problem, do you think there could be a parameter that is not right. The thread is so far out from one pass to another it seems like it is trying too make muti. start thread.

Thanks for you time

[Datum1]

setting the parameter for the timing is differcult .. i wanna see if anyone can do this.. keep me posted too.

[timlkallam]

Post your program

[timlkallam]

Hi mike i looked at one of your older posts it seems you have had this problem for a while .I also noticed that there are a few mistakes in the G76
program you posted.The R is in the wrong place Q should have no decmial point,29 on some machines is 60.I noticed you are using mastercam to generate your threading cycle. Unless you changed your mastercam post prossor it won't spit out the the correct threading cycle for your machine.
Do you have a manual for your machine if you do post a sample of your threading cycle this will give me an idea of what it should look like.

Lets try this tell me what size and pitch thread you want to cut .I'll write a g76 thread cutting cycle for it . If that does not work we can try a G92 thread cutting cycle .If still no luck we can try a G32 thread cutting command. If none of this works i think it may be an encoder problem.
Tim

[scubanick]

Mroy

I actually have a Daewoo puma 8s in my dept.
what thread are you trying to make
i use Surfcam for my programming
and i will send you a code and let you see what mine looks like

nickmthw@aol.com

[bkelsey]

From my limited experience in CNC threading on a Fagor 8020T controller, the CNC initiates the threading pass with the reference pulse on the spindle encoder. I could never get my threading passes to repeat. I tried an external cable from the spindle encoder to the CNC and it worked fine. Noise in the encoder cable was my problem. YMMV.