Mechanical Rigidity/Ultimaker 2
Ultimaker 2: no improvement needed
The Ultimaker 2 is an excellent example of a completely rigid cube design:
This design is superb. Every single one of the six faces is filled with panels that provide the full required set of rigidity for all six degrees of freedom.
- The top is a panel that looks to be a 40mm "picture frame" that is at least 4mm thick. If the hole gave a border less than 40mm then the panel could potentially start to flex and bow, thus defeating the purpose of it being present.
- The sides except the front (and probably the bottom as well) are entirely solid, providing excellent rigidity
- The front is again a panel that has an access hole, but the border is sufficiently large so as to not result in flexing.
- There are lots of attachment points between the panels, particularly in the corners, but also in the middle (to stop the panels bowing outwards).
Interestingly there are no internal struts: no extruded aluminium. The cube is entirely made from its panels. With this technique, as long as the assemblies within the cube are securely attached to all three panel faces then the assemblies are also constrained in all six degrees of freedom. If the assemblies themselves are also rigid then the assemblies, if placed in each corner, would double up as corner bracing for the panels.
Overall, this frame is a superb piece of engineering design.