Thor, or should that be Zeus?

[Chaz]

Yes Know about the accuracy of The DWH Epoxy but still think will cause trouble and then if you talking Chinese type spindles like 2.2kw how would you clamp it or stop it from sliding etc. Would need plates making or some form of fixture.?

Think I'd be going with more conventional Cartridge spindle into sleeve set in concrete. This will give more options for replacement etc. ie 40 taper
Also why not BT30 for 12K can get them with bearings rated at those speeds and plenty of holders that are balanced for higher speeds.

The idea is that it gets attached to a plate which screws in from the bottom.

At the moment the only reason I have not gone for a BT30 setup is cost mostly. There are numerous on the market but what is the cost to entry - £1K upwards by the time you add the BT30, Drawbar? What about motors? Do you mount from the top and do a direct drive or some form of belt setup?

EDIT, I may do the cheaper route first. I Can always make another 'outer' Z part and swap it out later.