How Thick Do I Need?

While waiting for church to start I found myself wondering if using .5" or even .375" carbon fiber composite might be excessive.  None of these parts carry any substantial loads.  Sheer and tensile strength are almost irrelevant.   Deflection,  which is calculated with Young's modulus is what matters 

I found this dandy calculator page for calculating deflection.   Now, I am making stuff using plates, not beams, but plates are if anything a bit stiffer than beams, but I am not building railroad bridges or fighter jets.

For a 3" x 1" x .125' piece of carbon fiber composite,  a 20 pound weight causes .04" deflection.  A .125" thick plate of CFC is lighter,  cheaper,  and faster to cut than  375".  The only weakness with using it is that there are places that I want a blind hole using stainless steel threaded inserts.  Going into the edge of .125" is impractical for 6-32 screws.

Another strategy is to bind the  125" sheet to a .5" thick piece either with epoxy or through holes, screws, and nuts, then through hole the  5" thick piece to its mating part.  

My Y-axis should return from Sherline tomorrow and I can return to this..

Another benefit of thinking about this before church is the realization that the quarter circles need blind holes on the radii cuts.  The only way to drill those accurately is to do that edge before cutting the quarter circle. Otherwise,  there is no square edge to put edge down in the mill vise.