1 Topic by Shameless

  • Shameless
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Topic: Vertical waviness/Extruder stepper precision

Hey guys, so I was noticing some vertical banding/waviness on my prints, print on the left. http://i.imgur.com/xWxOt49.jpg I think it's related to the fact that the extruder uses a stepper motor. From looking closely at it it looks like the microsteps that the extruder is making correlates to the bumps that create ridges. Messing with the flow rate I noticed that it shifted the ridges on the right print, starting with vertical ridges on the bottom layers, then getting progressively more slanted, probably related to the amount of microsteps per perimeter length.

Has anyone noticed/messed with this before? I'm not sure if there's some setting in the firmware that would make the extruder motor less jerky, or maybe if I messed with the X-Y jerk to offset it somehow. Any advice?

2 Reply by adrian (edited by adrian 2013-08-21 13:23:39)

  • adrian
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Re: Vertical waviness/Extruder stepper precision

You can dial down the vref on your extruder driver fractionally by hand - theres a few methods but I personally just set it to extrude 100mm's at 50mm/min and then watch the drive cog very closely and dial it down until it is very smooth and not jerky at all.

Alternatively, upgrade to a 1/32 stepper driver such as the DRV8825... this add more steps and combined with a good hand tuning will give you near perfect walls..

Other ways to eliminate it also is using a geared stepper or a gear-driven extruder... but the vref or vref+1/32 is a lot less fiddly smile

3 Reply by LMY

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Re: Vertical waviness/Extruder stepper precision

Hi! I had this problem a few weeks back and it went away after I calibrated the y-axis belts. I wasn't sure why that would affect the print walls that way, but the waviness went away immediately after. If you still have this problem and do decide to give that a shot, I'll be interested to know if that works for you.

4 Reply by LMY

  • LMY
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Re: Vertical waviness/Extruder stepper precision

Before (IMG_1021) and after (IMG_1020) calibrating belts.

I still have to tackle the banding on my SD2...

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