So one of the fun things about this project is the software. 

I have a web server that manages the print queue and dose all of the slicing/gcode generation.

There is a problem though. It is possible to slice a file larger than your build area in the 3d printer.

It is also possible you have more than one 3d printer and each one has a different build volume.

The fix to this I updated both the web server and the gcode sender client.

I added max x y z values to the server. This data is extracted from Slic3r and stored in the database.

I added settings fields in the gocde sender software (The software running on the computer connected to the printer) that allow the user to specify the max size of a 3d print for that machine.

I added the logic to the PHP scrit that communicates with the printer to check if the model is to large for the printer.

Wha la. Problem solved.