Thanks for your advice, yours looks quite a brute! If you say I'm only using 30V drivers and won't reach the 1605 critical speed, I think I'll use 1605 alround, I did misread about rotating ballnuts, I read ball screws, I'm not ready to go that far yet maybe another build, if you could read German and had the time, the engineer is very detailed in choice of components and build style, he even shows a thermal view of the critical points. As I said I'm mainly interested in wood and a little Aluminium, so I think this style will suit me. it still looks more stable than a router made out of wood.

Ian