Hi Ross,

I asked about balance because the spindle I bought had balance holes in the collet nut. It's another step towards a more refined and accurate machine.

The material you were researching is from manufacturers who make machines which run all day, and under a high workload. They are always pushing the boundaries of what is possible, and charging £1000's for them. Maybe you're beating yourself up a bit there with what you might achieve, but bravo for giving it a go.

I've yet to run my machine yet (hobby on back burner for now) but similar machines on the internet spin up nicely to 24,000rpm and I'm expecting the same. No it's not geared - I suspect it is like the section view I posted a while back.

This is the machine I bought:
http://cgi.ebay.co.uk/1-5KW-WATER-CO...item35aaca00f4

Sorry, this is the blind leading the blind unless some has actually done this . . .