Odd deformation on print

Bavilo · 2017-05-13T10:52:30.000Z

Hi everyone,

I have designed a model and for some reason there are deformations which are definitely not in the model. I have printed this model twice with different slicers. Same deformations on the same spot.

I thought it might have something to do with the Z axis but it runs smoothly and does not skip.

I am using a Prusa i3 MK2S.

I also printed a 6mm x 6mm x 40mm pillar and placed it in the exact spot where the deformation of the previous print would happen. Surely enough the pillar came out perfect.

So what could have happened here?

img_20170513_124113.jpg4032×3024 2.18 MB

img_20170513_124238.jpg2185×2641 644 KB

img_20170513_124322.jpg4032×3024 2.13 MB

Bavilo · 2017-05-13T10:53:42.000Z

I am talking about the thicker layer at the very top.

Xeno · 2017-05-13T12:37:54.000Z

its because of cooling rate of the material changes during the print, if you look the deformation is exactly where the bigger bottom volume changes to the smaller detail on top,

and changes again when the top detail goes from hollow to bigger volume.

When filament cools at a different rate it changes shape compared to other parts of the model.

Bavilo · 2017-05-13T12:45:17.000Z

Ah makes sense. Any way to deal with this?

Xeno · 2017-05-13T14:30:59.000Z

Very difficult, setting temps for different layers is a possibility, but you need a paid slicer to do that, and you would have to test what temps are needed for certain layers.

It could be a cooling fan problem, blowing too hard or not enough.

You could print at a cooler temp, or You could also try another material that has less shrinkage when cooling.

It’s a common problem and most just deal with it, or sand the sided smooth

Andrew_247 · 2017-05-13T15:52:00.000Z

If tweaking the settings doesn’t fix the problem, print it with a raft. The bottom won’t be nice and smooth, but the warping should disappear.

moddhayward · 2017-05-15T08:05:09.000Z

Could this be slight over-extrusion?

I say this because the bulge looks like it happens when the handle starts being solid (from U section) and if there was slightly too much filament being put down then it would have to go sideways, creating this bulge.

Could you try slightly reducing the flow? Say to 0.95 and see if this has any effect. I suggest just printing one handle, not the whole object, as a test…

wirlybird · 2017-05-15T14:29:37.000Z

If you look closely I think you will find that your issue occurs at the same point/layers where the bottom of the model is printing also. Or am I looking at the wrong spot. You really need to identify what we are looking at exactly.

Try turning the model 45 degrees and see if it still does it.