Rigid tapping dwels at bottom with running spindle

Hi all,

I have a problem with rigid tapping on a lathe with life tooling and a fanuc Oi-TF controller.
The machine this occurs on is not very much used even though it is already a year old and supplier customer support is nearly zero.

When the tap reaches the botom of the hole it dwels there for about a second with the spindle still running before reversing the spindle and retracting in Z. See the attached video at the bottom

program used is

G97 S300 M53
G0 X465 Z10
M29 S300 M53
G84 C0 Z-23 R-5 H[360/6] K6 F[300*1.25]
G80

have been playing around all day without any succes.
Tapping without rigid tapping by the way gives the same result : dwelling at bottom of hole with spindle running.

Why do you have both C and H on the G84 block?

Why repeating M53?

Are you sure that rigid tapping is enabled on your machine?

Quote:

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Originally Posted by sinha_nsit

Why do you have both C and H on the G84 block?

Why repeating M53?

Are you sure that rigid tapping is enabled on your machine?

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Your right c and h do not have to be both in de G84 block
And the double m53 also isnt nessecery but this shouldnt and doesnt give any problem.
Riged tapping is a standard option on this machine and it is possible to force some riged tapping related errors to show.
Also riged tapping is enabled in parameters.

Does the position page reflect the dwell? It almost looks like backlash.

You may have a bad parameter setting. I was just at the Fanuc website and downloaded the OiF Function Catalog. Look in the feed section and there is tons related to different ways to feed in rigid tapping. Things like time constants and bell shaped acceleration/deceleration curves and much more. You might want to take a look through your parameter manual and see if something has been changed from factory or you spot a parameter change you think will solve your problem.

The comment about backlash does not seem completely out of question. Should be able to sort of check that out by grabbing the tool with your handing and seeing if it will give a little.

Dave

Hey duivenhok,

What is the brand of your machine ?
Do you have the correct M & G-code list for the machine, are there example programs in manuals available ?
Sometimes a non Fanuc code is used for tapping, on our lathes it's different for each brand/machine.

When nothing works for the moment you can always buy yourself a FAHRION CET-GB floating ER-collet, approx. €110, -
The FAHRION CET32-GB (ER32-collet) has a bore-diameter from 4.5mm to 12.5mm, always buy the biggest and make adapters for smaller diameters.

Regards,
Heavy_Metal.

can any one give me parameter settings in rigid tapping on cnc lathe p16 oi-td fanuc series? and give me sample program... thanks in advance