Radius compensation in lathe cycles

[Zudo]

Hi,

I would like to know if there is a way to use radius compensation in cycles like G71 G72, my machine ignores the compensation only works with G70.

Thanks

[dcoupar]

According to the Fanuc 21iT-B Operator's Manual:

11. Tool nose radius compensation cannot be applied to G71, G72, G73,
G74, G75, G76, or G78.

[Geof]

Compensation is often okay with G70, the finishing cycle, so one way to do it is have U and W values that leave on enough material in the G71/72 for a compensated finishing cut.

[Zudo]

Originally Posted by Geof Compensation is often okay with G70, the finishing cycle, so one way to do it is have U and W values that leave on enough material in the G71/72 for a compensated finishing cut.

it wont work in some cases. i dont understand why this happens...

[Geof]

Originally Posted by Zudo it wont work in some cases. i dont understand why this happens...

You are not alone.

I use a Haas lathe which is similar to Fanuc and I finished up doing the roughing for a profile using G72 with the tool radius approximated in my code. Then I wrote code for the correct profile and ran two separate finishing cuts using compensation but not using any canned cycle. Tedious but it worked.

[Zudo]

Originally Posted by Geof You are not alone. I use a Haas lathe which is similar to Fanuc and I finished up doing the roughing for a profile using G72 with the tool radius approximated in my code. Then I wrote code for the correct profile and ran two separate finishing cuts using compensation but not using any canned cycle. Tedious but it worked.

I have read somewhere that if the compensation is turned on and of inside the cycle it will work, i dont belive but i didnt test yet because im on vacations...

[dcoupar]

Originally Posted by Zudo I have read somewhere that if the compensation is turned on and of inside the cycle it will work, i dont belive but i didnt test yet because im on vacations...

AFAIK, you can turn it on and off in the finish shape definition and it will be applied during the G70, but it is ignored during the G71, G72, and G73 roughing cycles.