obmilllivebuild published a new build:

Read more about this build...

 

I would think that the Nema 23 motor and acme screw on the Z is more than capable of moving a dual extruder system (it handles the Bosch / Dewalt routers quite easily). If someone really wanted to use this as a full time 3D printer, I would suggest increasing the lengths of the Z C-beam by 100mm. To get a 100x100x100 build volume, you would actually need to increase the X C-beam by at least 50mm also.

 

I assume you mean the C-Beam Machine's gantry style versus the XY table style. The XY table style is pretty stable in small format. The gantry can be harder to keep the Z rigid enough as the span increases, but is really the only way to get to large formats. So, if you need a compact system, the XY table style is simple to build and reliable. If you need larger formats, it is important to make the side plates of the gantry strong and rigid and the beam needs to stay straight across its length and not twist / pivot against the spindle forces.

 

I uploaded another file in the Files and Drawings section, called OB_MINI_MILL_TRIPLE_THREAT.zip. In this zip file is the entire assembly saved as a STP file. You can use my affiliate link below if you decide to order from OpenBuilds.
OpenBuilds Part Store