This is the microdrop system mounted on my lathe. These pics were taken halfway through a job, hence the swarf everywhere.

First, here is the regulator/ oil reservoir. It is a standard regulator/filter unit with the filter removed. The water drain was replaced with a pipe fitting. This is now the oil outlet. Air comes out the original air outlet. The bowl now becomes the oil reservoir. The block to the left of the regulator is a solenoid valve to control the air.



The air and oil lines go into a manifold. This routes the air into a loc-line hose. The loc-line hose has a small pipe running down the centre for the oil.
The manifold is attached to a pot magnet so it can be easily mounted anywhere. You can see the needle valve mounted in the oil supply pipe.



Now to the business end. This is the nozzle. As you can see, it has had several arguments with hot swarf. When taking heavy cuts, the swarf comes off very hot. This does not seem to affect tool life but you do get quite a lot of smoke. Flood coolant would help control the heat but it is too messy for my liking. To be honest, this system works better on the mill than on the lathe.

The nozzle consists of an outer tube that the air flows through then a small diameter inner tube that passes through the outer tube and projects out the end by about 1mm. The air flows through the resultant ring shaped orifice at high velocity, picking up ambient air and slowing down in the process. This gives a colum of fast moving air while not consuming too much high pressure air. The oil is supplied at air line pressure to the inner tube through a needle valve. By the time the air passes the  end of the inner tube it has slowed down considerably so it doesn't have enough engergy to turn the oil into a mist. Instead the oil forms a stream of small droplets.

 If you look closely at the end you can see the small pipe sticking out at the end of the brass nozzle.


Here is the unit mounted on my lathe.