Thanks everyone for the quick replies! What I distill is that the speed is not that bad at all. I really like the accuracy of my printer not, so I think further tweaking will not help me. Somehow I think the speed should increase for the printers to become more useful for bigger items. Or do other (non-reprap) printers have a much higher speed?
Printers like the makerbot are slower. If you want to go even faster you have to reduce resolution and go with bigger nozzles. The volcano from E3D is a good example. It can spit out low res super strong parts really fast but you wouldnt use it to print a figurine.
I think that the speed can be increased if mendel changed. I suppose that the throubles starts for the inertial mass that move in alternative motion. If we introduce a calibrated spring we can delete the problem, and speed can be increased.
Confirm. 50mm/s for Prusa i3 is good value. I have some issues with bearings at the moment. The max reasonable value I could achieve was 100mm, but the quality becomes worse. Reason is rigidity/inertia. Moved masses at Prusa are pretty big.
Deltas have way lesser moved mass and I could achieve ~150mm/s (I’m still trying to improve the mechanics) and reasonable is ~100mm (mostly because frame is made from acrylic glass (PMMA) and in current version is not rigid enough to withstand higher speeds (quality loss due to printing head inertia).
Overall speed currently sucks on all available printers. To improve the technology must move from single point printing (printing area 0.4mm x 0.4mm) to some kind of array (linear or other shape, for example 4mm linear array may imporve 10x), or to some other physical principles.
The Volcano is great… however, the basic thermodynamic laws become the limiting factor. With a 1.2mm nozzle and T-Glase material (2.8mm), the heater struggled to maintain 280c at more than a 30mm print speed. We were able to print 5lb models in 20hrs.