Over extrusion or something else? It's not right! (Pics & Vid)

[Jinja 1]

Hi

I'm having a problem getting the first layer/outline of some circles/holes I'm trying to print on a large piece.  No matter what I do I cannot stop this from happening.....

As you can see the PLA is sticking to the nozzle and making things worse, but it looks like the nozzle is just dragging across stuff as it prints.  The material is Rigid Ink 2.85mm PLA, but this happens with Innofil also so, it's not the filament.

 

Here's a video....

https://www.youtube.com/watch?v=OaHPFqQw3pY

The build plate is spotless and always cleaned with 99% IPA before every print.  All the rods are oiled and the Z screw greased.  The print bed has been calibrated and the filament is feeding with no problems.

I've even slowed the print speed down, changed layer size, bed heat, nozzle heat, everything I can think of. I've used so much filament and time trying to sort this out, but I'm at my wits end!

Please help.....

Edited December 19, 2016 by Guest

[IRobertI 520]

I would level the bed a little bit closer to the nozzle so that it squishes the plastic more into the bed. Sometimes I also feel that it's better to use a thinner first layer than the default in cura. But if you level a bit closer I think that would help a lot.

You could also consider adding a very thin layer of glue to help with adhesion.

[geert_2 557]

As Robert says, try leveling the bed a bit closer to the nozzle. In my experience that helps a lot. Disadvantage is that you get a little bit of "elephant feet".

Additionally, to improve bonding, you might also try my "salt method": wipe the build plate with a tissue moistened with salt water prior to printing, so that the glass is covered with a very thin mist of salt, almost invisible. For the full description and photos, see:

https://www.uantwerpen.be/nl/personeel/geert-keteleer/manuals/

For me this gives a very strong bonding when the glass is hot (60°C), but no bonding at all after cooling down, so no difficulty in removing the models. And it is very easy to apply, no need to take the plate out of the printer.

This salt method works very well for Ultimaker and colorFabb PLA, and it still works but not perfect for ICE PLA. So it may work for your PLA too. Let us know.

It does not work for ABS (requires some sort of glue instead) and PET (prints better on bare glass).

[Jinja 1]

OK thanks guys, I will try adjusting the bed first

[zoev89 73]

I tried the salt method mentioned by Geert_2 and the first print came out perfect. I will see how the build plate holds. Typically I could only print 1 time at the same location so lets see what happens.

[Jinja 1]

Will give that a whirl too

[zoev89 73]

After some more prints I did have small parts having issues where a stronger bond is necessary. There I will stick to the wood glue trick. Having a method where the parts are easy removable has certainly a value. So it depends on your needs. If you have large parts the salt method has preference because removing will be easy. Printing small parts with little contact area I would stick to wood glue where part removal is typically not a problem.

[gr5 2,167]

Jinja you want to squish the filament more into the glass - that's the main thing. Also you should use a liquid glue solution. More info here - it's a long video but I couldn't make it much shorter and keep in all the good info. After watching this you will be an expert at getting parts to stick to glass and with a part this large you need to use all the tricks.

 

[tomnagel 126]

* There is some difference in adhesion between the 2 sides of the glass (it's not coated or treated or anything, but it has to do with the way the glass is produced). You can try to flip your build plate.

* I'm curious to see the video you posted above, but "the video is marked as private"

* Could you make a close up of the brim? I think the brim will tell whether or not the distance between your bed and your nozzle is ok.