Thanks for the advice once again. My intention is that the top section above the spindle is going to house the "controls" for the cooling/misting system. There will be vents in the housing once finished covered with a mesh to allow air in and out but due to the "other" bits in there I wanted to try and keep it clean.

I will however keep an eye on it all and monitor the temp of the unit. I was already planning a digital temp readout on the control panel so one for the spindle is no additional problem.

Another issue encountered. These linear carriages and the infernal little ball bearings that keep falling out every time I have to remove the rails!!!!!!

So I got on the 3D printer and made some rail sections to insert in when the rails not in there. They came out pretty perfect. I'm assuming new carriages are usually shipped with something like this?

Anyway I've still had a million of the little buggers fall out. What's the best way to keep them in as your feeding the rails? Ive tried grease but they still come out its the last "2" that are hardest to fit.

Patience? - I'm all out of that and there's none on back order :p