fanuc 6tb G71

[chris wedgwood]

Does anyone have experience of roughing into undercuts with G71, the manual refers to two types, and says type two will go into undercuts, it states that to call type two there should be both x and z moves in the line P, when running the tool is positioned in the programme line before G71 then stops error 65, x and z have been programmed in the line P, ........

[Machineguy]

What ver of Mastercam are you using?

A snippet of code will help so we can show you what's happening.

 

Type 2 will follow the shape you programmed.

Type 1 will break it down into liner moves.

Remember your tool has to FIT the undercuts or it cant get into them. In that case you will need a plunge type tool to get the excess out on a separate tool path.

[taperlength]

Does anyone have experience of roughing into undercuts with G71, the manual refers to two types, and says type two will go into undercuts, it states that to call type two there should be both x and z moves in the line P, when running the tool is positioned in the programme line before G71 then stops error 65, x and z have been programmed in the line P, ........

Type two roughing is an option on Fanuc lathes.   If your program has both X and Z moves in the P block, that is the instruction to do a type two. But if the option is not enabled in the control, the alarm 65 is the result.

Mastercam will rough undercuts without using a G71 canned cycle.