A request for information on your mill or lathe

[Toolmaker51]

Interesting thought.
Myford ML7 with plain white metal bearing and unused for 5 days - 6 Ohms
Chuck turned ¼ turn - 3.3 Ohms
Oil drip feeds opened and about 4 drops dispensed form each feed, chuck turned about 3 turns - 2.5 Ohms.
As others said above, one thing that never enters your head, and I have been associated with this old machine for over 50 years.

Rather conclusive test, we may allow a machine to warm up first then, lube. This says turn over un-powered a bit first. Anyone have results where 3 phase differs from single?
Is there a non-conductive container to get result on clean oil alone? Judging that compared to pure water not being conductive, minerals make it so.

Every bearing has clearance. Gravity pulls horizontal shaft "through" the oil film as it drains away, contacting bearing. Intuition says that be more conductive than a couple rotations spreading lube. Unconnected to oil, but what travels to ground when power is off? Does this justify practice in big plants, each machine [esp CNC] having individual or share adjacent ground rods?

My building stored 55 gallon steel drums of printing inks and solvents, many many dozens of them stacked up. A bare *12 copper encircled the perimeter, with multiple jumpers and clips for the barrels, terminating in just one 8' ground rod at edge of building inside the drip line. I don't think forklifts entered; material set on dock with pallet jacks. 100% No smoking within ~40'. No electricity other than minimal warehouse pendants, to a single switch. Wiring just EMT, not any of sealed types.
That's a lot of fuel, with hardly any source of ignition.