This may have come up somewhere but I couldn't find any reference to it. I was playing around dialling in my printer and thought I'd try a really fast bridge speed - just for the hell of it and on the basis that the filament might not sag so much if stretched quickly. What I discovered is that slic3r (version 1.2.9) uses bridge speed for the first top solid layer after infill. I suppose that's technically correct as the infill has voids in it which need to be bridged. I'd forgotten that I had set it so fast when I went to print the next test piece which was basically a 100mm x 100mm x 3mm cube. It was fun watching the print head moving at 150mm/sec but not much fun when I realised that it's impossible with Diamond hot end to melt enough filament that quickly.
So here also is another little tip. If you want to determine how fast you can print, do a big cube, say 100mm square or greater and keep increasing the speed until the extruder starts to chew up the filament because you've reached the maximum melt rate. Then back it down a bit.
Edit. Speed settings are under the "Print Settings" tab and there are settings for "Solid Infill" and "Top Solid Infill". Neither of these are used for the first layer of solid infill. That one uses "Bridges" (which is what caught me out).
Edited 1 time(s). Last edit at 10/22/2016 04:27PM by deckingman.