Forgive my ignorance of 3d printers...but would it be possible to make a design that wasn't a clamshell design? It would increase what the blaster can handle (without separating at the seams), and, if designed right, could provide easier access to the internals (think M16/AR15 pin system/upper and lower receivers).
Again, pardon any ignorance I have on this topic, just trying to help.
You could certainly do this. The design does become somewhat more complicated due to the increase in support material it would require, though.
I've even seen an AR-15 lower 3d Printed by a few different people (though not with a low cost printer, yet)
I really don't think it would be necessary for springers though, as you can just add material to the critical clam-shell parts to reinforce any weak points (and add more screws if necessary)