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Random bumps keep apearing. I dont know how to get rid of them.

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Posted · Random bumps keep apearing. I dont know how to get rid of them.

My printer is leaving these bumps all over the place. Im not sure if its these travel moves causing them. My retraction is set to 8mm at 45mm/s. Bumps appear with coasting on and off as well as z hop. Ive tried changing coasting settings, z hop settings, wipe settings. No changes from benchy to benchy Any help would be greatly appreciated



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    Posted · Random bumps keep apearing. I dont know how to get rid of them.

    I probably can't help you much because for my use I really don't care about bumps and don't really pay any attention to them but I noticed all those strange travel moves to the right.  What's that about?


    Please post your project file so I can see all your settings.  Do "file" "save project as..." and please post that here.


    If your goal is to get bumps on a benchy then you did everything right - you got a huge printer, you printed in shiny black filament and went for extra thin layers.  That's the perfect combination for the most visible bumps.  If you go for white filament and just as important, a matte filament and print on a very small printer (like Ultimaker 2go) then it will be 10X harder to notice any bumps (they'll still be there if you have a microscope).


    In general, bumps are caused when, due to high pressure, a little plastic squirts out sideways from the nozzle.  It could be the pressure is too high (meaning printing too fast or if there is a speed change), bad retraction, sudden slow down (maybe due to too many points in STL or changes in print speed (bad settings)).  Basically all manner of things can cause bumps but almost every issue is improved by slowing things down.  A lot.  Like 2X or 4X (which would cut the pressure in the nozzle by 2X or 4X and make those bumps 2X/4X as more infrequent and 2X/4X smaller but they might still be there if you are determined enough to see them).  Also set all print speeds to be the same speed as speed changes can cause quality issues.


    Those weird travel moves off to the right could be the cause also.  Maybe.  Anyway they shouldn't be there - something is wrong.

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    Posted · Random bumps keep apearing. I dont know how to get rid of them.

    Im an idiot. The moves turned out to be wipe nozzle between layers. Idk why I even had that turned on in the first place. However, this wasnt the issue. It was a nasty z seam that protruded from the sides due to improper retraction. I enabled retract at layer change and changed my retraction extra prime amount to -0.1mm^3. These two seemed to fix this issue.

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