[max90272]

Hello all,

I am a mill guy and now making my way to the lathe... more specifically a NL1500 from Mori-Seiki with Fanuc style control.
I would like to hear from lathe guys about the advantages and disadvantages of using M3 with right-handed cutters versus M4 with left-handed cutters? It seems to me that using M4 would be a more rigid set-up because the pressure is applied towards the base of the machine... but I am sure there is more to it than this.

Thank you.

Max

[MILLMARK]

I have always felt the same way about the pressure being exerted down on the ways when turning M04. Some shops I've worked in programmed all roughing in M04, and finished in M03. I think most good lathes are rigid enough to go either way, unless you're doing some serious hogging. Also consider that when turning M03, the chips are directed down into the chip pan, instead of spraying everywhere.

[underdog]

It seems to me that using M4 would be a more rigid set-up because the pressure is applied towards the base of the machine... but I am sure there is more to it than this.

Max,

I always agreed with this approach. You should direct the forces down into the ways. Number two, and very significant,the operator can SEE the insert face to evaluate its condition before making a cut. and its easier to reach if it needs changed.

Only drilling (which has balanced cutting forces anyway) and threading, which is a lite cut by definition, are backwards.