Hi Keith,
I'm intrested in building a Bldrbot Pro to replace my Prusa i3. I can get all the dimentions for the printer from the .skp file, all the dimentions but one. In the pictures you state that the Z drive belts are closed loop belts from RobotDigg, my question is, what length are the belts?
Regards
Sally

 

Thanks for that Keith

 

Surprised this didn't get much attention. Any more updates? This machine is very logical to me. Would love to know if you've fleshed this put further.
I too have been planning on using the double ended nema. It could also be used for the x or y gantries in an ultimaker type setup as well. I think the fabrikator from turnigy uses something similar for their y movement.