Increasing Build plate size?

[curious aardvark]

yes you can increase it on your own. Without rebuilding anything or changing your motherboard. Sometimes geoff overlooks the easy - ducttape world - option because the hard option is easy for him :-)

Bear in mind that the whole width of the of the machine is not used because the specs are given so that both heads can reach everywhere on the build plate.

All you need to do is drop a wider plate (3mm glass or aluminium would be fine) onto the existing one and use a cold bed plastic like nylon, pet, pla etc. you can then use the right head to just print stuff on the right and the left head to print on the left.
I haven't measured it but I reckon another 5-6 inches of width would be easily achievable.
Not sure if it'll print with more depth. But you could probably squeeze a bit more depth out if you wanted to.
Easy way to check is to move the printhead as far forward as it'll go and see if it's gone past the end of the printbed, if it does then there's your extra print depth :-)

That's the easy bit. The hard bit is getting the software to use the new width of the build plate.
I suspect you'd need to start using a fullly compatible 3rd party software like simplify 3d. Not sure if makerware or repg will let you designate a larger printing area.

Proftweak might.