Underextrusion Problem on smaller layers

[ELLOMS 3]

Hi,

I am currently working on a project where heavy use of Colorfabbs Bronzefill filament is involved.

I printed a lot with Bronzefill and consider myself quite experienced in the use of it.

Nevertheless I ran into a problem I can't solve.

On the smaller layers of my print the printer seems to under extrude quite a bit.

I also noticed that smaller layer heights have a positive effect on it as well as larger layer heights, infact I only experience this problem around 0.15 mm layer heights.

Furthermore I tried to tweak the retraction settings to see if that has positive effects on my problem. It didn't have much of an impact. I can also rule out problems with the nozzle though I changed it recently and updated my feeder system to the iroberts alternative feeder.

I am not experiencing similar problems with PLA.

But anyway here are my settings and some pictures of my problem. I hope you can help me with my problem because I am getting very frustrated by now.

Layer height: 0.15 mm

Speed: 50 mm/s

Temp: 219 C°

Wall thickness: 1.2 (0.4 mm nozzle)

Flow Rate: 104%

Retraction: 4.55mm 25mm/s

Thanks for your help!

[tinkergnome 927]

It doesn't look like underextrusion to me. Is it printed hollow?

I think it's more a problem of "non closed top surfaces" then with small areas...?

Perhaps it only needs some infill or more top layers (and/or more shells)?

Also printing the shells "outside-in" could help.

Which slicer do you use?

[ELLOMS 3]

Yes it is printed with 0% infill. I'll try printing with 1.2 mm Top/Bottom Fill in order to get a even shell. Never thought about this actually.

Thank you for your help! I will update you as soon as I get the print done.

Edited December 31, 2015 by Guest

[ELLOMS 3]

Printing with more Top/Bottom Fill doesn't solve my problem. The specific regions still look the same. While watching my print i noticed that the inner shells aren't touching and seem quite thin whereas the outer shell has a solid width. My Outer shell speed is 30mm/s and my inner shell speed is 50mm/s.

Edited December 31, 2015 by Guest

[peetersm 124]

interesting, if you are getting under extrusion at 50mm/s and not 30mm/s then maybe raise the temp or slow down the whole print.

[ELLOMS 3]

I will try both and see how it turns out. Thanks!

[yellowshark 153]

I doubt very much it is under-extrusion; it is almost certainly printing a flat surface across a void. As a test I suggest you use the "cut off bottom" function on the advanced tab. I am a looking at your 2nd pic and what I assume is a shoulder that has the error. Using 1.2mm as your solid infill setting, I would "submerge" your model so you have about 3.5mm of the shoulder above the surface. Change your infill from 0% to 26% and run the print - sure stop it once the shoulder has printed. You should find you have a much better finish on the shoulder. A pic of the result would be useful, if it too does not print well

[peggyb 169]

you can also set the flow to 105%, that is what I always use.

[ELLOMS 3]

Raising the temp and lowering print speed didn't have any effect on the problem.

I will try your tips and see how it turns out, and update you with a few pics. Hope it will help and thanks again!