I've come home for the weekend - lots of post, including spindle.

Setting up the VFD was no problem. I've got a little 8L/m submersible pump for the water cooling. I've just tried it with a bucket of water and an odd assortment of tubing, about a couple of meters in total, and I got 1.3L/m flowing. I think that's fine.

With 5l of water in a plastic bucket the temperature rose by about 0.25°C/min. The spindle was only drawing 0.6A from the mains.

Going to make the mount later today and hopefully try cutting with it tomorrow

At 24,000 rpm is quiet enough to listen to radio and I can't hear it over the dust extractor...Also I can barely feel any vibration at that speed on the spindle body.