Hello,

I'm looking to build a large'ish 3 axis horisontal mill using EG. 7,5kw BT40 spindleI, travel is X=600mm, Y=400mm, Z=650mm, rapids around 30m/min'ish.

My intention was to first weld a structure in steel(20mm flanges throughout and 8mm braces across), get it annealed and then encase it in EG afterwards. I would encase piping to allow temperature control of the casing, both during the postcuring of the EG and grinding of guideway mounting surfaces, but also afterwards during operation...But it seems like "everyone" is just using some sort of inserts and now i'm starting to think that the inner steel structure might be a bad idea and actually make the machine perform worse than without it. I'm getting a bit nervous about the difference in temperature coefficient and that the poor damping of the steel might allow vibrations to propagate throughout the steel inside the EG....

Any thoughts?

/Thomas