Gantry design question

[Tenson]

I like the ingenuity but I think it's kind of a waste of expensive material. CF is very stiff for its weight, but steel is equally stiff. Since the weight isn't much issue, use steel. Want damping, then use steel box section with foam or sand inside. For sheets of aluminium or steel use constrained layers (I mentioned green glu before, bitumen and butyl rubber sheet is also good).

I design loudspeakers and in this area we pay a lot of attention to damping sheet materials for the speaker boxes. The BBC did a great amount research on this and concluded that constrained layer damping was most effective, although making it stiff was not the goal. So IMO use stiff materials and constrained layers, but don't worry much about weight.

[D.C.]

I like the ingenuity but I think it's kind of a waste of expensive material. CF is very stiff for its weight, but steel is equally stiff. Since the weight isn't much issue, use steel.

That is pretty much the conclusion I came to, CF has been used for CNC machines but only in the ultra high precision ones and I'm guessing the thermal expansion of steel and it's momentum put the CF ahead in those situations. For the size of those machines the labour cost is probably far higher than the cost difference in raw materials.

[D.C.]

Having said that if the price of carbon fibre comes down I would still consider it just because it looks so damn good!