Clarification on print speeds/print quality

I regularly come across references to print speeds eg 30mm/s, without specifying which speed is referred to.
My slic3r/pronterface front end has 7 print speed boxes: [ perimeters, small perimeters,infill, solid infill,bridges,travel, bottom speed ratio ]. Theres also in a separate area retraction speed. My guess would be that the usual reference to speed refers to the first of these (perimeter speed), but its not clear, so which is usually meant?

Also, given a speed/print quality trade-off which of the above 7(or 8) has most effect on that aspect?

I would also be interested to read any experiences with adjusting speeds to improve/decrease print quality.

Mike

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Prusa Mendel /Parcan Mk 2/1280 RAMPS 1.4/PC XP OS/Pronterface/Slic3r

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I think most often people are referring to Perimeter speed and Infill. The rest are special case speeds (bridging, small parts, etc)

The perimeter is the one that effects quality the most.

Infill can be as fast as your machine will go as long as the threads connect to the perimeter properly and don't thin out or break while printing.

Solid infill is important to get a good solid surface for two reasons. Texture of the last layer and solidity of the layers as fast solid layers over sparse infill can cause problems.

But the most important thing is giving the layer enough time to cool as to keep its shape and allow the next layer to be accurate. So small items need slower settings and large items can be printed really fast.

Also you have to be careful of the temperature required to print at different speeds. Faster needs hotter and slower needs cooler which can be a problem if you are trying to print perimeters at 30mm/s and infill at 150mm/s. Either it is too hot for the perimeters and they come out a mess or too cold for the infill and the extruder skips steps or stripes the filament.

Edited 1 time(s). Last edit at 05/11/2012 04:48PM by Sublime.

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Sublime, thanks.

A useful reply which I've already put to work with a separate small parts config file for slic3r & done some printing.

Thanks in advance for any further info.

Mike