Edit: The original parts were a bit too thin and it resulted to a bit of backlash during printing, so I significantly thickened the Y carriers. The backlash is gone and they can be printed flat on the bed now with no supports.
I made some adjustments to the two main X gantry parts of the Daemon:
1) The original hole sizes for the idlers were for M4 screws but their heads interfered with the rods. I reduced the hole size for the idlers to a M3 hexagon screw. It fits OK and taps the plastic on the other side.
2) The idlers were rubbing against the plastic slightly. I increased the clearance for the idlers a bit.
3) The gantry was, in my case, pushing the side rods apart (it was too long). I inserted a 4 mm spacing between the two parts and made the motor's screws adjustable. This way the two X gantry parts may have a small gap between them (or maybe not) but the motor holds the whole assembly together anyway, so it allows the X gantry to be slightly adjustable in terms of length. Even if your print is a few mm off, your gantry will align perfectly with the Y rods.