As requested by you, here is how to scale the farmhouse bed to a full size.
A full size mattress measures 54" x 75", compared to queen 60" x 80"
This means we will have to trim 3" off either side of the center panels for the footboard and headboard. You must trim from either side to keep the panels centered, instead of just trimming off 6" on one side. This also means that all the trim for the headboard and footboard will be reduced by a total of 6".
This also means that the frame will be constructed 5" shorter. If you do not require a frame, than you will not need to make these revisions.
(4) 1” x 8” x 8’ Pine Board $24 (For Panels)
Construct as noted in the orignal bed plan shown here, except when the panels are complete, trim 3" off either side as shown below. I use a rotary saw and chalk line to get a good cut.