My large printer ( the slightly older P4) has a carriage able to move 450mm in the X and 400 in the Z however only 250 in Y.
I have a print request for a print that exceeds the volume of my 300x300 printer.
(which with the cooling fans on is down to about 260 in Y anyway)
So I will be adding 4x 25mm aluminum tubes 560mm long and to new bearing shafts about 590mm long to increase the build volume on that machine to 450x450x400. Ill post pics of it being done and once its done.