I have just received my DIYCNC Breakout board! :D

this may sound silly, but this is the first serial item I have ever used! I have to find an old PC now!

Also took delivery of some M6-M12 taps.

Exciting stuff.

The supported rails in that picture were 250mm Long and the screw was 350mm, this allowed me to mount the screw supports above and below the supported bearings making it thinner.
I'm now getting 300mm supported rails, this means that the screw supports will have the be inline with the rail and that the Z axis will be wider.

would changing the ratio of Z and Y closer to 1 make it more rigid? I thought it was a bigger the better situation!

the ratio of the new design is about 2:1

the 2 being the Y axis.