I'm still a major proponent of wood construction, but I take a bit more of a high tech approach.This makes it sound like the time for MDF has passed ... which is likely true but some guidance would be appreciated.
I'd like to try to do stiffness and defection analysis of different sized MDF ribs and spars and compare that to a similar structure of extruded aluminum. My bias is that aluminum extrusion is used for convenience and other factors that have nothing to do with building a well engineered structure. Well engineered means the choice of materials is in line with the requirements for strength and the structure is appropriate for required stiffness.
It could be that extruded aluminum has superior strength and pre-made systems such remarkable stiffness, well beyond anything that is likely to be made with MDF, that it's not worth the time to examine. Am I trying to boil the ocean by not falling in line?
My next machine is a 4x8, dual spindle router built mostly from wood. The gantry is 67" long, and MDF. I calculated the deflection at about .002" with a 200lb load. (I think, it's been a while). It's an 8" box with 1" mdf panels. But the 1" is made up of 4 laminated layers of 1/4" MDF for added rigidity. I cut the parts a about 2 years ago, but still haven't assembled it yet.
Pics here: http://www.cnczone.com/forums/cnc-wo...ml#post1168468