Printing limitations?

What are the printing limitations of a rep rap. What is the maximum angle? For instance is the rep rap capable of printing a martini glass that has 45º outward angle? What about unsupported roofs? The whistle from thingiverse looks like has a "roof" that is only supported by walls. Could it print a small vertical doorframe for example? Basically my question is can the rep rap print without anything under it? Thanks!

Edited 1 time(s). Last edit at 12/30/2011 09:48PM by Nate711.

It can not print without some sort of support. Defining support is not that easy. Support can be a previous layer parallel to the print direction, even at some angle (>45 might work). Or support could be walls that are not parallel to the print direction (Spanning across two fixed walls).

I've observed that when printing across larger spans the material tends to sag initially then pull up straight when cooled. I'm sure as the span grows the material simply can't recover or recovers partially resulting in a poor quality print.

Not everything in thingiverse can be printed (look for photos that show an actual printed part) or they were printed with support material that gets cut away.

You have to try for yourself to be sure.

Thanks.