Why do bottom layers look glossy on round objects?

Hey folks,

I am trying to print a pagan tumulus. I want to achieved a uniform external wall. However, the bottom layers look differently - by some reason they are more glossy.

How do I avoid that?I am guessing that might do something with print speed of the layers…

Thanks!




My thought would be that the overhang area is printing slower and thus hotter resulting in a shiner surface.

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That looks a problem I ran into a couple of months ago. It has to do with travel speeds when the printhead is in motion between objects of different heights. It is not always obvious because you may find that one filament shows this phenomena while another does not. The cause is due to the fact that there are slight variations in speed that occur while moving from one object to the next when printing the same layer.

Here’s a work around. Change the print sequence from “by layer” to “by object”. All this does is force the print head to finish one object before it moves on to the next.

There is a big drawback in using this feature.

Within the algorithm, there is protective code that creates a huge boundary around the objects in order to ensure that once an object is fully printed, there is sufficient room for the entire print head mechanism to clear the object on the plate. This forces a HUGE gap between objects and really curtails densely packing objects onto a plate forcing one to distribute objects across multiple plates.

Here’s what that looks like when the slicer warns you. Obviously, auto-arrange objects will solve this but it will also move any objects off a crowded plate that would otherwise fit if the default print “by layer” was enabled.

Here’s a good video that discusses the issue from a pure speed by object. Note that he does a really good job showing how to use the alternative view menus to digs down into how to diagnose what’s going wrong.

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Next time after you slice, check the layer speed (colour scheme :arrow_right:speed), and you’ll likely see the point at which the nozzle speeds up. You can tune this by limiting the maximum flow rate in filament settings until all the layers become the same speed (equal slowest). The model will take longer to print but it will look a lot more uniform.

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Printing in “Silent” mode aka 50% speed mode might be a fix for models already sliced.

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