Rough walls in the printed box

[awydra 0]

Hello guys,

Recently I got my new Ultimaker (BTW it's a great machine!) but I'm still kind of green in printing... and probably that's why I have some weird problem with my printed model.

Here is the problem... I would like to print some simple rectangular box with four triangles at the corners. The model should look as in the attached photo.

http://farm9.staticflickr.com/8541/8610450807_7acb7fc562_b.jpg

However, the result is slightly different than I expected. Instead of smooth nice vertical walls in my box, I got some rough (even ugly) walls. Actually, the walls look nice at the bottom of the box but the problem appears when the printer starts to work on the triangles in the corners.

The attached photos showed the problem probably much better than my words...

http://farm9.staticflickr.com/8115/8611558636_1721d991b3_b.jpg

http://farm9.staticflickr.com/8241/8610451883_7222c359b6_b.jpg

The model was made in Sketchup and exported to .stl format. I used CURA 13.03 to slice and generate a gcode.

Does anybody know what can be the reason of this bad print and how to solve the problem? Maybe I should try a different slicer?

 

[gr5 2,167]

This is classic "under extrusion". You could be slipping in the feeder - maybe you could try tightening the feeder. More likely you can fix this with higher temp. What temp are you printing at?

Since this model has no stringing problems (for example if you had 2 vertical posts, you might get stringing between them) you could go up to 240C no problem. But later on other models you will get stringing so maybe just go up by 10C from whatever you are printing at now. Or slow things down a little bit to reduce the pressure in the print head.

See this also:

http://umforum.ultimaker.com/index.php?/topic/1763-bad-surface-on-printed-parts/?p=12318

 

[awydra 0]

Thank you for your response, gr5.

I'm using 220 C... but right now I don't think there is an 'under extrusion' problem. I already printed out some small Yoda's head and a small cylindrical box and I didn't have any problem. Actually the quality was impressive!

What I noticed, the roughness in my box is noticable even in the software Cura (13.03) just after the slicing. In other words, the roughness is already saved in gcode!... so I don't think there is some problem with the printer. There must be a problem either with my settings in Cura or with my model... but I still don't know how to fix it...

 

[gr5 2,167]

Do you have joris turned on? SF (the slicer that cura uses) has some weird bugs when you combine joris with a part that doesn't have only smooth walls. The bug looks a lot like this and can be visually confused with underextrusion.

More here:

http://umforum.ultimaker.com/index.php?/topic/1746-lack-of-extrusion-in-certain-part-of-a-part/?p=13006

 

[awydra 0]

Sorry for the late response... I had some unexpected issue with the thermocouple... but right now it's fixed so I can return to my problem :mrgreen:

gr5, 'joris' is turned off... so that's not the issue... but maybe I should try to turn it on and see what's gonna happen?

BTW, thank you for the interesting link. I went through it and even if I didn't find solution to my problem I still learn a lot about the 3D printing.