Analysis of linear motion systems for a large scale FDM 3D printer

Abstract

3D printers have been around for quite some time in one way or another. Only in resent years with programs such as Reprap, an open source 3D printer that can self replicate a lot of it's own parts, has helped greatly in bringing 3D printing into the price range and homes of hobbyists. When constructing one, the current models are small and not sturdy looking, which is not good for scaling up so that it would be able to do a large quality print. This of course does not matter if detail in the print is not important, but if the printer is to be used in an architectural firm for model building, detail is important. How can a printer be made larger but still print quality prints? The linear system of a normal size Reprap MendelMax would have to be replaced to achieve this. Two linear systems that were relatively inexpensive and easy to acquire, the Makerslide and the Open Rail linear systems were good candidates. Calculating and experimenting with these systems revealed that the Makerslide would only deflect 0.12 mm on a span of 1 meter. Compared to the normally used 8 mm steel rod that deflected 12.96 mm. This is from a load of 2.21 Kg, which is roughly the weight of 3 Greg's Tilt Extruder's, for multi color prints. So if only using 1 color and there for 1 extruder the weight would be reduced substantially and the deflection as well. These numbers are acceptable for model building in an architectural firm for a derivation of a Reprap MendelMax with a print size of 400x400 mm. This information also implies that one can go even bigger than that, but will probably need to upgrade electronics and motors.