On Sat, 06 Apr 2013 06:35:17 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Gunner Asch fired this volley in
:

Its probably because the tool nose radius is bigger on the insert tool




Gunner, a larger radius might give a better surface finish (with
everything else rigid and strong), but it will also increase the forces
causing a toolholder to spring relative to the work.

I don't know if I follow your contention...

LLoyd

Yes..it does take more force. As do negative rake tools. But thats
why industrial machines are made tough, strong and rigid.

Im sure that most of you here are familiar with negative rake tools?

They are not for every material..but work very very well if you have
the hp and rigidity for it. My 7.5hp Clausing 1500 gets used a LOT
with negative rake tools. My Hardinge HLV-H..does not. Zero rake is
best for it in most materials.

Id be using positive rake tools on light, flimsey machines. And have
a corresponding loss of surface finish.

As for tool nose radius....

http://www.sandvik.coromant.com/en-g...s/default.aspx

Some interesting discussions on TNR

http://www.homemodelenginemachinist....-radius-16526/

Gunner