Hey Guys, With all the tool change work that the E3D guys have done, I'm really interested in doing something like that for my printer which would mean that I can make my gantry MUCH lighter than it is now since I won't have to plan for carrying multiple tool heads at once. The problem I'm running into is that I want to use the lightest linear rails I can for my longest axis (X axis on the Y gantry), such as 20x40 but with a span of 1755mm and an estimated load of about 670g (1kg max), even with 20x60 rails I'm still looking at roughly .1mm or so of deflection in the center and I'm not nuts about that. I think it would solve the problem if I used a 20x80 but then the weight is getting back up there and I might need to beef up the Z gantry the Y gantry rides on. In any case, my actual question is: Does anyone know of a way to make a 1755mm length of 20x40 or 20x60 stiffer so there is less deflection and if not, what light weight material could I substitute that is stiffer and can support 1kg with a minimal deflection <.05? Apologies if there is not enough info or if what I wrote is confusing, I'm on a super short lunch and that time just ran out but I wanted to get it out there!