CPMT inserts?

[Kram]

When rotating the bar I always reset it to be on centre, which was a pain to do many times.

you also need to take into account the chip breaker which on a rotated tool may not be presenting itself to the material correctly

This was one reason I were interested to try the CPMT's. I've found that CCMT chip breakers often dont work well in bores - or atleast not nearly as well they work on OD turning. I assumed that might be why CPMT's exist but Im still a bit unsure what there intended for, why they would be chosen over the other. The insert has 4 degrees more clearance but the combination has 11 degrees less.

Im aware if I rotate the bar, it could stress the brazed V joint which is supposed to be horizontal.

 

[ukracer]

Just to add, what I was meaning when I said


Was because we were talking about rotating the tool to get the geometry correct due to the insert being the wrong geometry for the holder.

So it would be off center?

 

[Hood]

So it would be off center?

Yes unless you adjusted the height of the toolpost holder which it seems was done. It is still not an ideal scenario, inserts are made to fit holders, if they are too thick then they will likely need rotating to get the correct clearance. If the clearance angle of the holder and insert are different then the insert will not seat properly and would almost certainly not be secure.