Why doesn't a TNMG indexable drill exist?

[Japazo]

I understand that a regular TNMG isn't cut with consideration of a relief for drilling like a normal indexable drill insert. They make boring bars with negative insert angles to accept TNMG inserts ( I own a few and love them) so why cant that same theory be applied to drills? The outer insert would have the taper to clear the back-side corner of the insert, and would clear the way for the inner insert so it doesn't rub. This would make for a good flat bottom drill with a very versatile insert (We use TNMG's for internal and external turning already).

Am I just too dense to clearly see where the major problem is? What prevents a tool maker from making a TNMG drill? If this could be accomplished I could use one insert for three of my major turning applications, and eliminate having to purchase another one altogether. Any ideas?

[roundabout]

Think of where the chips would go. To create the negative axial rake you would need to be able to feed the tool the inserts would have to be angled in such a way that would have a left handed helix initially. This would shoot the chips straight into the cut. On top of that it would need the same negative radial rake that your boring bars have.

I'm not saying this would be impossible to make work with some hardcore coolant directed in just the right way. What I will say is it would take a lot of trial and error and I think the resulting tool would be so scary looking I don't think it would sell.

[txcncman]

Build one and see why it won't work.