G41 on fanuc and tool breakage detection

Hi everyone!

I have been involved in CNC using and machining for a long time.
I also have a fairly modern lathe at home, which I deal with as a private business plus.
I recently got ordering a special piece that I would need to produce in larger quantities. However, it has an R5 radius on it and I was thinking of using the G41 function on the machine. The machine is controlled by FANUC.
Unfortunately, the radius size is good until 40 pieces and we are in tolerance, but then the radius size goes away and we are out of tolerance. I saw there is a radius correction option in offset, but it didn't work that much either. My question would be if anyone has any idea what the trouble might be or how their experience could be best used.

My other question would be that I have read the manual and can use tool breakage monitoring in it. Unfortunately, nowhere did I find a description of how it could and should be used, run on the machine (FANUC control).


Thanks in advance for your help!

You'll need to tell us what machine and what specific control you're using. Tool breakage detection is usually unique to each brand.

I have an MURATEC MW100 with double spindle.
I read in his book about tool setter that there is a help for it, but I didn't even get it with the machine and I can't find anything about it on the internet

The “R” register in the offset page will have no effect unless you are using G41/G42 TNR comp. Is this an inside radius or an outside radius? Is there a detectable amount of wear on the insert?

Most tool breakage systems are NOT going to detect tool nose wear that merely puts the part out of tolerance. Heck, alot of them won't even trigger unless the tool is destroying itself.

Make sure the TNR is set correctly. I used to teach Applications for a major MTB and this was a CONSTANT source of headaches as folk would have the wrong tool tip in the offset page or the wrong tool radius (if any at all). There is a chart in the Fanuc Manual as to proper TOOL TIP DIRECTION. Use it. Also get the radii correct. Make sure you have proper lead in / lead out.