Edited 1 time(s). Last edit at 11/03/2011 02:08PM by Nudel.

The infill method is nothing special, RepRap (and most 3D printers?) have been doing that pretty much from the beginning. I personally prefer 15%-30% hexagon-infill and three shells on my prints. The bowden cable has also been use for a good while, with various - mostly not very good - results.I hear the ultimaker nozzle is 0.4mm, and that's not anything spectacular. [ www.flickr.com ] The high quality is obtained by stretching the filament a lot and running a bunch of very very thin layers. From what I understand this is a trick done with netfabb. Now, more layers = more time, a lot more time in fact, so they make up for it by going insanely fast and very hot (and at the same time they bypass some of the issues with the bowden cable).Theoretically you could use any printer to do that, but since most printers have a much larger mass to move around, they'd have to do it slower, and it'd take ages to finish even a small print.This method is awesome and creates stunning prints, though it does have its drawbacks. The lack of control over ooze with a bowden, means it'll string more when traveling over spaces. For all I know you might be able to brush the strings off, and might not be an issue at all. But since so many people seem to make their pride in "straight-off-printer"-shots, and a lot of people react badly to easy-to-remove plastic string (I've had that discussion a fair amount of times) it's only natural people print what shows off the printer the best. I think this is why most ultimaker test prints are either single-walled awesome structures, and/or objects with few to no bridges in them. I haven't looked very much into this though, so please add pictures, links and more information.Point is, if you count the weight of the plastic laid down, a (well tuned and built, I must say) prusa with 0.5mm nozzle can be faster than an ultimachine running at super-low layer height. For mechanical parts, that kind of speed and a good enough quality is what matters, now how fast the head travels along in itself. The limiting factor is often the hot end not being able to melt the plastic fast enough, and not the mechanical construction. You can overcome this by running the hot end very, very hot, but you will have a lot of ooze...So can we get quality and speed at the same time? Sure, one way of doing it is running dual head extruders with one tiny nozzle (0.25mm?) for detailed perimeters, and a bigger nozzle (0.6-0.8mm?) for the infill. The infill nozzle could be on a bowden cable to keep the weight down, as oozing inside the model wouldn't matter much.I would also love to see a bowden-type extruder with a lightweight motor close to the nozzle to support the retraction of the main feeding stepper. It could add that extra little fine control that's needed.This discussion, as many others, boils down to, "what are you going to use your printer for?". If you want to print the type of objects ultimaker excels at, and don't want to tinker and build or care much for the RepRap idea, an ultimaker might very well be your best choice. Personally I find myself more interested in designing, testing and building printers, than printing (more or less useful) stuff off thingiverse. Which quite frankly stuns me, as it is not at all why I started building a RepRap in the first place.Edit: Oh man, that did become a wall of text. And it took so long to write most things were already covered by others. Oh well..---Nudel Blog with RepRap Comic