Yes, I do agree that a perfectly flat bed is better than not.
But, there are many other aspects that I think one might miss.
1) I.e. object warping that is common, this I think cause much more "errors" than this.
2) The common 8mm rods for the x axis bend due to extruder+hotend weight, this lowering the object in the middle of the x axis. This I have measured myself with a dial gauge and it is pretty significant.
3) X/Y is probably not perfectly orthogonal, neither X/Z or Y/Z. But because it is hard to measure on a 0.10mm resolution over 200mm no one is actually discussing that.
Putting the first layer down is very important, i.e. if you want to print a 0.3mm first layer and the bed has a 0.5 min/max sway you might not be able to put the first layer down at all. But a print with a 0.5 sway might still be acceptable. With this one would still be able to print. I.e. measured on my RigidBot BIG (bad) plate I have a 0.65 sway over a 200mm distance which is actually only a 0.325% "error" which I don't think is that much. (hmm, or should it be over the whole plate appr 400mm, then only 0.16%).
This feature helps getting the first layer on the plate, nothing more. And specially for a big plate like mine this helps a lot.
Edited 1 time(s). Last edit at 03/21/2015 08:05PM by epatel.
