Solved Bumpy Print Texture

I am getting a weird bumpy texture on the perimeters of my prints. The texture starts out fine and gets worse in the direction of the print head travel (left to right). The prints also have 3 distinct regions of bumpiness that correspond with the internal structure of the part (the top and bottom sections being more hollow than the middle section).

Does anyone know what would cause this or how to fix it?


Right Side:

Left Side:

 

Could also be hydration, but start by calibrating the extruder

 

Thanks for the suggestions. Ill check them out when i next have the chance.

 

Does not look like water as the print was bad.... better... bad again.. This looks like your printing a bit too hot. Or maybe too cool.. Start with the hottest the filament recommends and then keep changing the temp lower until you see a sweet spot. I normally give it at least 1 min of print time between each 2C change. Some PLA likes 190C some need 245C all depends on where you got your filament.
Once you found the best print temp, try with fan on.. then off.

 

For me, it was a combination of 2 things. 1) I had to take the extruder out to clear a jam 1 or 2 prints ago. I have the R1+ model that has a single screw with flip-out locking plate to secure the extruder. I thought everything was put back, but I found the screw was loose. 2) calibrating the extruder. I found mine was under extruding.

 

I know this will sound crazy but I was getting the same thing off & on. Turned off my ceiling fan close to the printer and it cleared it up. Maybe getting to much air flow on the print area?

 

It turns out the problem is a combination of print resolution and perimeter speed. If the print speed is too fast for the resolution of the curve, the print head will overshoot its target and then try to correct it causing a pattern of overshooting and overcorrecting for the rest of the curve (makes a grinding sound). that is why the print looks fine at the beginning of the curve and gets worse as it goes on.

The easiest solution is to lower the outer perimeter speed, lower the output resolution of your CAD software, or a combination of the two.

A better solution would be to tune the dynamics of the printer through the EEProm so that it doesn't over shoot in the first place.

EDIT: I did also calibrate my extruder. the EEProm was set to under-extrude slightly, but we had already set the extrusion modifier such that it pretty much evened out.

 

i had the same problem. are you connected directly with your computer via usb? All of my problems went away after i got the xxl led screen and printing with just the sd card.

 

Interesting...

Yes, directly to the computer

 

Interesting...

yes, directly to the computer