Problem of printing converging last layers

[3d_held 0]

 

 

Hello ultimaker forum,

I am new here and you guys already helped me out to find a good setting for the last layer.

But this time it is not the same problem which is usually reported and I could not find a similar topic. Therefore I want to show what I have experienced so far.

As you can see in my media album, my ultimaker 2 is not able to print converging last layers, it seems like the nozzle do not know how to print it.

It mixes up the layers and it results in a bad condition.

Furthermore, my printed disk should have 3 points where I can connect the object to another one. But it did not print aswell.

The results are the same, I suggests it has something to do with the top layer settings, but I do not know what to change to make a good print.

Do you guys have any suggestions?

 

[illuminarti 18]

I can't see any photos in your album.

 

[3d_held 0]

Now you should be able to see them

 

[yellowshark 153]

It will be the reduction in layer time as you approach the "point", almost certainly. IE subsequent layers are laid down before the previous one has dried and they melt together. It depends on the size and the geometry but slowing down the print speed as you approach the issue area can achieve the desired result. If not you will need to print concurrent items to increase the layer time at the end; pia I know

 

[illuminarti 18]

Yes, as yellowshark says, you need to slow down the printing of the upper layers to give the layers time to cool. You can set the minimum layer time on the 'Advanced' tab in Cura - I'd try 7.5 seconds as a starting point. There's a risk that or very small parts, that might slow the print so much that the head spends forever over the print, and the stray heat from the nozzle can also melt the plastic underneath. in that case, you can either print multiple pieces at the same time, so the head goes somewhere else while the plastic is cooling, or enable the 'cool head lift' option in Cura's 'Expert Settings' - that will move the head up and away from the print during the wait. That might cause a little oozing onto the outside of the print if the nozzle starts to drip as it waits - but usually that can be cleaned up fairly easily at the end of the print.

 

[3d_held 0]

Thanks,

I was able to improve my printings. I uploaded new pictures in my gallery.

As you can see, the disk is better now. First I just made it slower and enabled the cool head lift on, but it was not satisfying, the points were too messy. Then I disabled the cool head lift option and set the "minimum layer time" to 9 seconds. It looked better but there was still too much material on the points. Finally I used the plugin tweak At Z 3.1.1.

Here are my important settings for the best disk I have printed so far,

Minimal Layer time: 9 sec

Cool head lift: No

Tweak At Z 3.1.1

- Layer No: 14

- New Extruder 1 Temperature: 185°C

The ring looks better aswell, but the outside looks unclean, now. I tried it with and without cool head lift. The pictures which are uploaded are the best results so far. These were printed with the cool head lift option.

Also I had to clean up my print afterwards like illuminarti predicted it.

The settings for the rings are

Print speed: 30 mm/s

Cool head lift: on

Minimum layer time: 8 sec

Is there anything I could do to improve the rings?

I slowed it down to 30 mm/s but I did not try to print it lower than that. Is that the only option to me to get a better result or are there other parameters I could work with?

 

[illuminarti 18]

Print several at once, so that the head can go do something else while the plastic is cooling.