Try Cura, the new Cura has coasting in beta testing.
@Topias_Korpi That make sense by their names, 
thx…
@David_McGuigan I would, but I like having my internal perimeter at a high speed, which doesn’t need to be accurate if printed after the external perimeter. If I do the inner first, then i have to set both speeds the same to obtain the same surface quality.
@Panayiotis_Savva I’m not a fan of Cura, plus it always air prints when i try it. xP
@Karl_Schlacher I did a search and found some info on it. I’ll take a look at it and see if its viable in my firmware.
@Aric_Norine Ah, I know where you mean. But the values don’t have any context. Do you have any recommended settings for a Robo3D? If not that printer specifically, here is a pic of my printer to see the hardware:
missing/deleted image from Google+
@Kura_kuea speed or quality, your choice? 
@David_McGuigan Haha yeah. I understand, but I’m trying to push my printer to the limit. 
Well the good news is i found an issue: the extruder bearing was rubbing and bogging it down, so that got fixed with a file. Bad news: now that the extruder is working properly, two days of calibrations down the drain. Back to printing cubes and tuning extrusion. >:’(
But still, you learned a lot and you got a better understanding of what is going on. So did we. And on top of that you found the real culprit. Not bad.