Greetings all. I am going to build a large format fdm 3d printer (18.875" x 48.5"). I scored a nice remnant of mic6 aluminum to use as the build plate and I have been itching to make a large format printer that uses ball screws so I never have to adjust a belt again. Top speed is not my concern; low maintenance and stability is more important.

I’m drawing up an idea of what I’d like to do, but need suggestions. In the picture below, the z axis actuators would be leadscrews because that axis will only move on each layer change. Speed is no issue there. The Z axis actuators will be supporting the X axis actuator and Y axis actuator along with hotend/steppers. I estimate that the X/Y/Hotends will have a total weight under 10kg. The hotend itself will likely weight less than 3kgs... so not throwing a lot of weight around.

For the short run (18.875") could I get away with a 1204 ballscrew? I was leaning toward a 2020 or 1620 for the long axis.

I also need ideas in support rods, all that is missing from the image. I was hoping to weld up some type of steel tube frame over the top of all this to attach supports to.


Thanks for any input!