Posts Tagged ‘Offsets’

Variables and Tool Offsets

Variables and Tool Offsets


In macro pro gram ming gen er ally, and in on-machine prob ing (in-process gaug ing) par tic u larly,


the cur rent val ues of var i ous off sets change fre quently, and have to be con trolled au to mat i cally,


for the most re li able and re peat able re sults This is done through var i ous cus tom made macro pro –


grams and rou tines Into this cat e gory be long two spe cial groups of off sets (also called com pen sa –


tions) that re late to cer tain mea sure ment val ues of cut ting tools:


u


Tool length angle machine offset


and the related applicable G-codes:


G43, G44, and G49


drilling Machine


u


Cutter radius offset


and the related applicable G-codes:


G40, G41, and G42


Val ues and set tings of ei ther group of off sets can be read di rectly by a macro pro gram, or writ –


ten to by a macro, us ing the sys tem vari ables of the Fanuc con trol sys tem De pend ing cnc equipment on the


Fanuc model, the us age of these vari ables may be some what com pli cated In or der to or ga notching machine nize the


pro cess, Fanuc dis tin guishes the tool off set ap pli ca tion in a macro by three spe cial groups, known


as the Tool Off set Mem ory Groups Even if a CNC ma chine does not have a macro op tion in stalled


or ac tive, it is a good idea to know what type of off set mem ory the ma chine has This knowl edge


is very im por tant for stan dard CNC pro gram ming as well, and it is sur pris ing how many CNC


pro gram mers and op er a tors do not have a clue of what type of the tool off set mem ory a par tic u lar


CNC ma chine ac tu ally has Chap ter 5 cov ered the sub ject of tool off set mem ory types in suf fi –


cient depth Fo cus of this chap ter will be the re la tion ship of these off sets to sys tem vari ables


The tool off set mem ory groups are re lated to the par tic u lar con trol model, and can be es tab –


lished quite eas ily by look ing at the con trol screen, and press ing the OFFSET but ton key on the


key board The num ber of col umns and the col umn head ings (col umns con tents) will pro vide the