Printing issue with breakaway material

[ejendres 0]

I'm having an issue with printing the break away material. I'm getting a bad finish and theres a black residue that builds up on the nozzle and will drip all over the plate.

 

I'm using the stock settings for the breakaway material in Cura.

 

Any ideas?

[ejendres 0]

Just as a follow up, I have cleaned both nozzles and it continues to extrude a black goo along with the breakaway.

[gr5 2,004]

I've seen something similar with other filaments.  For me it's usually that the filament sticks to the outside of the nozzle for a while and caramelizes slowly over maybe 10 minutes and then falls into the print.

 

It's not usually a problem for support material, right?

[gr5 2,004]

Why don't you post your project file.  Do "file" "save project as" and then post that file.  Then I can look at it.  I'm particularly curious about the support material cool temperature - the inactive nozzle is supposed to cool a bit so you don't leak as much but also so you don't caramelize it like might be happening here.

[ejendres 0]

On 6/9/2022 at 11:44 AM, gr5 said:

Why don't you post your project file.  Do "file" "save project as" and then post that file.  Then I can look at it.  I'm particularly curious about the support material cool temperature - the inactive nozzle is supposed to cool a bit so you don't leak as much but also so you don't caramelize it like might be happening here.

 

I'd appreciate that. The file is attached.

UM3_wip5.3mf

[gr5 2,004]

The temperatures look fine.  It cools the breakaway when not being printed to 215 and 230 when printing it.

 

I don't know what you can do about the burnt breakaway falling into your print.  I don't use "pla breakaway" and have no familiarity with it.  I use other products (PVA or PLA as a breakaway for petg).

 

1) Anyway, I noticed some other strange things.  Your part is basically a box with shelf-gaps inside.  Those gaps are printed as a single layer of breakaway.  But there is no way to remove that breakaway as it is sealed in the box which has sides, top, and bottom.  Do you need those gaps in there?  For some kind of airflow?  Waterflow?  Or can those gaps be removed?

 

2) I don't think you need any support in your entire part except for this one red section as shown.  You can get rid of all the other support by either:

2a) changing the support angle overhang until the side supports go away and also chooseing "support touching buildplate"

2b) Use support blockers everywhere except the red seciton shown below.

 

[geert_2 556]

I haven't printed with Breakaway yet. But in my experience with PLA and PET, thin black flakes usually come from the inside of the nozzle: this is material that decomposed against the wall of the nozzle, and at some time breaks free and goes through the nozzle. While thick lightbrown blobs of goo usually come from the outside: this is material that accumulates on the outside, often when printing with overextrusion, and then decomposes and sags onto the print in a blob.

 

Stay with the printer and watch closely: often you can see what is happening and why. Maybe you can also smell why and when the problem occurs (the cause).

 

Based on the color and the amount of blobs, I would guess that you print too hot, or with too little flow, or both. But this is pure guessing; as I have no experience with Breakaway...

 

What you can also do to reduce the amount of support, is design custom supports in CAD.