ODD RIPPLE EFFECT IN CYLINDERS

[Deereengineer]

IM PRINTING SEVERAL SMALL CYLINDERS ROUGHLY 3/8 THICK. IM GETTING THIS ODD LOOK TO THEM LIKE THEY HAVE RIPPLES. THE ONE ON THE LEFT LOOKS GOOD BUT THE FURTHER FROM THAT ONE THEY ARE THE WORSE THEY HAVE THE PROBLEM. IM PRINTING IN ABS AT 235 DEGREES. ANY IDEAS WHAT COULD BE CAUSING THIS?

[zemlin]

My first guess is crappy filament - too much diameter variation.

Another possibility is that the bed is shifting during the print. That can happen if you get minor nozzle collisions with the parts during the build. Retraction with vertical lift can avoid that.

[Jules]

I was really hoping that someone who actually prints a lot of ABS could answer that for you, 'cause it might be worse/better for ABS.

Guessing here......temperature banding? Those are awfully small - I'm not sure there's much you can do....space them a little farther apart on the bed? A lot farther apart to give more cooling time during travel?

That looks cyclical.... and unfortunately you probably need to check the PID settings, but again....not my area of expertise.

I'd try slowing it down, spacing them out, and printing inside of an enclosure (for ABS), but i'm no expert on it.

[jimc]

abs is usually bad with tall skinny objects because the heating and cooling will move the cylinder slightly as it prints giving you something like what you see there HOWEVER the large base on those even looks terrible so i would not just blame it on that. judging by what i can see of the base, it really looks like you have some over-extrusion going on there or something.

[Jules]

Just curious......What does a failing thermistor look like? Would it mess with the temps enough to cause something like that in cycles?

[jimc]

it could. same with a poorly tuned pid setting. you would need to watch the temp graph to see whats going on. a 5 deg variance wouldnt do anything like that. it would take more. that seems really regular though like a pattern. if it wasnt showing a poor print quality on that base then i would say its just normal tall thin model / abs syndrome OR a bent Z axis all thread. this does not seem to be the case though

[insta]

IM PRINTING SEVERAL SMALL CYLINDERS ROUGHLY 3/8 THICK. IM GETTING THIS ODD LOOK TO THEM LIKE THEY HAVE RIPPLES. THE ONE ON THE LEFT LOOKS GOOD BUT THE FURTHER FROM THAT ONE THEY ARE THE WORSE THEY HAVE THE PROBLEM. IM PRINTING IN ABS AT 235 DEGREES. ANY IDEAS WHAT COULD BE CAUSING THIS?

IMG_0411-01.JPG

Does it do it on all ABSes? Try another plastic.

eSUN ABS+ is a good start.

[Deereengineer]

I agree that the base looks bad too. Im using an extrusion multiplier of .97 right now and if I go any lower I have separations between threads on the top layers. But yes it still seems to be overextruding . Anyone got any wisdom about setting that?

[zemlin]

Maybe it would be worth printing something that turned out well in the recent past - just to see if it's a hardware issue.

[Jules]

Maybe it would be worth printing something that turned out well in the recent past - just to see if it's a hardware issue.

Good suggestion. And keep an eye on the temperature chart while it prints.