the Z bits are done! aside from the limit switch holder. I still have to come up with a brace bracket for the Z towers.

The left side top Z bracket uses a 608zz bearing to steady the Z axis lead screw, along with a place to capture the smooth rod. I've added supports along the part to help keep it in place as it only bolts on to one side of the aluminum extrusion.

The right side Z bracket is really a slimmed down version of the left side minus the lead screw 608zz bearing holder.

Also I made a silly mistake in trying to finish the lower z section and added a support wall to the Z smooth rod capture post.. you can get a bolt into the back bracket.. so I removed that wall and punched holes through the piller. 

all that's left to model is the support brackets for the Z towers and the entire x axis.. that one will be fun.

so far I've printed all of the parts to check for fit etc. they seem to be good but I won't know for sure until I order a set of M4 nuts and bolts.

I found a pretty good deal on 8 in x 8 inch by 6mm aluminium plates. I think those will work good for a bed once cut down.

once I get everything modeled I will know what kind of printing volume we are looking at :)