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BobinAtlanta
(@bobinatlanta)
Trusted Member
Unwanted ripple

I am doing a series of test prints to better understand speed and its effect on smoothness.  I am using a hollow 20 mm half-sphere dome that is 2 mm thick and printing it at every speed Slic3r allows.  A ripple appears in the pieces at all speeds that is not in the CAD drawing or the resulting sliced drawing.  It is in a different place with each speed.  In the picture, you can see it starting just to the right of the writing ".05 U" which was the speed of this printing.  But it occurs in all of them.  

What causes it and how can i make it go away?  

Posted : 27/10/2019 3:38 pm
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(@)
Illustrious Member
RE: Unwanted ripple

Hard to say - but here are two possible places I see what appear to be artifacts. The VFA area shows the normal stepper motor related vertical artifacts.  Buying and installing better motors with a higher step count and making needed changes to firmware can reduce the noise. Doing a tweak to the drive profile can also help - it's a simple test and then you set numbers via LCD.  Search the user mods forum for VFA - lots of additional discussion there.  The other thing that kinda-sorta looks like its there (hard to tell) is belt and frame ringing due to jerk and acceleration settings.  Belt tension needs to be right to minimize it - seems a good tension is 6 lbf.  Reduce jerk, and slow acceleration to see if it's what us causing the waves. Adjust accordingly.  And if you change belt tension, remember to recalibrate XYZ to get back to the correct step cal (belts do stretch).

 

Posted : 27/10/2019 3:55 pm
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Illustrious Member
RH_Dreambox
(@rh_dreambox)
Prominent Member
RE: Unwanted ripple

When converting a CAD file to STL you should convert with as high resolution as possible.
A low-resolution file can produce the effect you are showing.
Different CAD programs have different settings, my picture shows the dialogue from Autodesk Inventor.

 

Bear MK3 with Bondtech extruder

Posted : 27/10/2019 4:46 pm
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