INDEXABLE TOOLHOLDER CNMG 12

(OCT 2007)

JOB DONE MAN!!

This lathe tool is gonna be used for roughing and longitudinal machining of rusty pieces of steel.

I have bought on ebay some really hard inserts CNMG 12 04 12 with super grade KT935 , thought for roughing and interrupted cuts.

As for the make of the DNMG holder I had to install the rotary table on the mill, plus the vise on top of it.

This CMNG holder requires a side rake angle of 6° as the normal angle for the negative inserts , this time of 6° too.

To position the 16*16 bar on the mill with a double axis inclination I invented this solution: 6° on the main vise to hold the second mini vise, and 6° into the mini vise to hold the piece.

doing this I can get 6° on the X and 6° on the Y of the holder.

All this combine must rotate with the rotary table.

finally I can say that it is impossible to make such CNMG holder without sines and TWO vices.

There is no difficult machining, just some calculation of angles with the rotary tables.

The CNMG inserts works at -5° from the 90°, which can be obtained moving 4 times and 5 holes the rotary table indexer.

Sorry I did not make any more photos of this procedure, but I got only the final holder.

complete kit.

insert sitting with -6 X and -6 Y inclinations

tough kennametal insert mounted. I am using a simple M5 steel screw (allen key head

the screw tap is made 0,250 mm in offset from the real center, this is because the inserts must be pulled towards the holder sitting sides

this shot , makes easy to understand the negative inserts -6° angle required to machine without touch the rotating part on the lathe with the side of the inserts.

positive inserts already have a inclined side, so they don't need a -6° on the tool holder.

another algra toolhoder for the new tool.