pattern repeat

[ac123]

hi, i dont uderstand how to program using pattern repeat on a LTC system 10T on fanuc controls. is there a simple way to understand it. thanks

[dcoupar]

G73 is similar to G71 and G72 in that you define the finish shape in the subsequent blocks (ns to nf). While G71 roughs in a Z (turning) direction, G72 roughs in an X (facing direction), and G73 roughs by following the finish shape.

The manual says that it is used to rough premachined stock, or castings or forgings. I'm willing to bet that 95% of the programmers out there have never used it. IMHO, it's not an effective way to rough a casting.

[chrisryn]

Originally Posted by dcoupar G73 is similar to G71 and G72 in that you define the finish shape in the subsequent blocks (ns to nf). While G71 roughs in a Z (turning) direction, G72 roughs in an X (facing direction), and G73 roughs by following the finish shape. The manual says that it is used to rough premachined stock, or castings or forgings. I'm willing to bet that 95% of the programmers out there have never used it. IMHO, it's not an effective way to rough a casting.

95% of what I machine is castings I have never used G73. I use G71 and G70 all the time.

[ac123]

so how would you machine this angled groove with a turning tool, because in g70 and g71 it would rough it then on the final cut try to take out the angle groove in one big cut..
sorry for the poor drawinng

[chrisryn]

Me personally I would use a groove tool to rough it out then make a finish pass with a turn tool. Not real sure that I would use a canned cycle at all.

[dcoupar]

I just might use a G71 "Type II" if I had the option. Or, I might give the old G73 a try, again, if I had the Type II option.

[adamant]

Originally Posted by ac123 so how would you machine this angled groove with a turning tool, because in g70 and g71 it would rough it then on the final cut try to take out the angle groove in one big cut.. sorry for the poor drawinng Attachment 61662

Use a G72 to rough it with a groove tool and then finnish it with the same tool using G1.

G72W.03P0(P is zero so you don't hit the wall)
G72P1Q2U0W0F.005 (U and W are zero because you are finishing with G1)