Placement of the nut doesn't have to be set within one of the support pieces (i.e. y-axis nut in the y-axis bearing support). I personally like the simplicity. If the hole is too small, the nut can split or crack the MDF. Alternatively, the y-axis screw can be positioned just above the y-axis lower bearing support. The x-axis can also be positioned just below the bottom gantry support. With the measurements I used, the z-axis is not as flexible; however, if the y-axis bearing supports are a little longer, the z-axis nut can be offset. These alternative locations will enable the positioning of a homemade anti-backlash nut.