Gaps in Z-layer

[sam706 0]

Hi all

I've have had my ultimaker in a few weeks now and everything has been fine and working well.

However now all suddenly i've been getting gaps in my print at the Z-axis.

It seems that the platform drops a few steps to much att certain times, or that it feeds plastic to little at certain layers.

However it isn't always the same layer, this can shift.

In my album i have uploaded a few pictures how it look like.

: http://umforum.ultimaker.com/index.php?/gallery/album/119-whats-wrong/

In the other album, i've have a few printed things that is from the begining, that doesn't show any gaps.

Notice the green and blue toolholders, it is printed from the same file from the sd-card, but the green one is printed a few weeks ago, and the blue one just recently printed.

You can at the gaps break the part very easily.

It doesn't care what color of filament, the gaps is showing in green, silver or blue PLA.

I've tested different tempratures from 190-230, it doesnt seem to affect it.

I'm now very tired of trial and error, what can be wrong?

Mecanic, software or what?

So what is your idees?

//Sam

 

[owen 19]

Hi Sam

It probably isn't dropping. It's probably not extruding properly for a layer.

Check your tension spring on the material feeder, your bolt on the feeder is clean. Or are you printing too hot or too cold?

 

[illuminarti 18]

Post a gcode file so we can take a look at your settings. Also, are you sure that the extruder drive is correctly assembled and locked into place?

 

[gr5 2,265]

We don't have a clear and obvious single answer. It could be a few things.

It looks like underextrusion. Here's a picture that shows what underextrusion looks from the side:

(the white picture)

http://umforum.ultimaker.com/index.php?/topic/1872-some-calibration-photographs/?p=13081

The final picture with the blue and green parts looks like underextrusion the most. The gray parts with one layer extruding almost nothing and then it starts back up - harder to say what that was. Probably a clog of something that eventually popped through the nozzle (dust). Or could be slicing problem. I know you said the same gcode worked sometimes but show it to illuminarti anyway.

1) Could you post a picture of your feeder? It should be able to lift 22 pounds of weight on the filament when there is no other resistance. That's a lot of power.

2) Also post your gcode like illuminatrti asked and especially the one for those gray parts with a single bad layer

3) Also make sure you aren't printing too fast (for example if layers are .2mm then keep it under 100mm and print at 50mm/sec to see if problem goes away - if .1mm layers then keep it under 200mm/sec and see if printing at 100mm/sec makes problem go away).

4) Also you might want to go up to 240C (makes the plastic flow more like honey)

5) Also make sure the spring in your feeder is compressed down to about 11.5mm. What is the current length when clamped shut?

6) you may be getting tiny particles of dust sticking on your filament so try to keep things very clean. These dust particles can clog up the nozzle for a while but eventually the tend to break up into tinier pieces and eventually it starts working again. Illuminarti uses tissue paper wrapped around the filament held with tape to keep the filament clean as it is pulled into the feeder. I have a much cleaner room and rarely (but sometimes) have trouble with dust.

 

[illuminarti 18]

... Illuminarti uses tissue paper wrapped around the filament held with tape to keep the filament clean as it is pulled into the feeder. I have a much cleaner room and rarely (but sometimes) have trouble with dust.

 

Actually, no, I don't :-) I think it was Ultinoob who I first saw propose that idea. Although it's not a bad idea. Depending on the supplier, new filament can pick up a bunch of dirt in manufacture and handling, let alone in the environment that you're using it.

 

[sam706 0]

Hi guys

I will post the code, a question about where to post it though, Can i upload it in text to the forum or do i have to post it at a fileserver somewhere in which format?

Thanks for all of the answers,, and ideas, even if they vary very much

I will take some more photos tonight and post.

 

[illuminarti 18]

If you click 'more reply options' to bottom right of the reply window at the bottom of the thread, then you should get a different editor that includes the option to attach files.

 

[gr5 2,265]

That doesn't do it for me. I have to go to the gallery first and upload pictures into there then when posting a reply I click the "my media" button next to the smiley icon.

 

[illuminarti 18]

George - you don't get an 'attach' option? I can't embed pictures in a post unless I stick them in the gallery first, but I do get an 'attach files' option. Do you not get that? Perhaps its because I am a moderator and/or was a beta tester...

 

[gr5 2,265]

nope. Looked again. There's a "my media" link and in there is an "attachments" thing in there but that doesn't seem to do anything.