Ordinary soap should work as emulsifier maybe.
Water cools, oil lubricates, its both important.

Probably just some kind of oil with a high viscosity.

Sinter tungsten carbide (TC) or poly-crystaline diamond (PCD) blanks in appropriate shapes.

Cast ceramic grinding tool blanks (Boron Nitride?). Dress them against each other in odd numbered sets on a CNC grinder/dresser.

Grind the tools on a 5 axis CNC grinder.

Use laser metrology (measurement) throughout to get high accuracy and precision using the wavelength and straightness of of the laser as references.

Coat the tools with a hard ceramic such as TiCN or TiBN.

I know this is high tech. You can see why I’m saying “Not for a few years”. Let’s be clear: I expect to do this. Just not now.

We can probably make HSS tools sooner. However, carbide tools are required for high speed machining or hard turning or working efficiently with abrasive materials including MDF, High Si Al alloys, and cast iron.

I think we can rely on the current status quo to provide us with TC inserts at reasonable cost for a few years yet.

It seems to me that the drill bits are a vitamin for the moment (at this stage we can’t make them, so we must eat – import – buy – them into the system).

When our replab distributed industrial base is a lot more mature, we’ll start making high precision things from hard materials, but I think that’s over the planning horizon on the road map at the moment: many other capabilities come first.

Two possible improvements occur to me:

- Use coolant. Cutting coolant can radically improve tool life, cut quality, and cut speed. Recirculating flood coolant systems are easy to make. I’ll publish the details of mine if you’re interested.

- Use a drill with a replaceable cabide tip insert, such as these spade drills . The super-hard insert lasts something like 10 times longer than a HSS drill and is cheaper to replace than a whole new drill. Result: reduced cost per hole for large numbers of holes.

Demented