PLA not sticking to Breakaway

[Tomasz_M 5]

Hi everyone!

 

I need a little help here with the Breakaway material. I have recently bought my first spool of Breakaway and tried my first print, which came out a total failure. I am trying to print a PLA part on a Breakaway support, however the PLA does not adhere to the Breakaway at all. Both PLA and BA stick to the built plate fine, but not to each other. On this batch I've tried printing parts both sticking directly to the build plate and ones that lay only on the BA surface, the outcome is the same.

 

I do not know what is the problem. Maybe it is not the adhesion it self but the gap (interface) between PLA and BA is too big?

 

Did any one had the same problem? I use default Cura profile for PLA and BA. Do I have to modify something in the settings?

 

[Dim3nsioneer 557]

If you don't use active leveling make sure both printcores are well leveled, i.e. make sure the z offset is set correctly. Otherwise perform an active leveling with clean nozzles.

[Tomasz_M 5]

Active levelling took place right before described print, clean nozzles.

 

Moreover, I need this print so run it with PLA+PVA combination ant it looks perfect so far.

Edited March 14, 2018 by Tomasz_M
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[Tomasz_M 5]

Hi, I'm still trying to solve my problem. I have analysed the layer output in Cura and it is what i have stumbled upon.

 

This is the layer view of same print as above using the PVA profile which works perfect. As you can see the proper print (PLA) touches the support (blue):

 

This is the same layer without any view change but with Breakaway profile chosen. You can clearly see the problem here, the gap between support and print is huge (4-5 layers at least):

 

Can any one point me out what I am doing wrong? Which setting should be altered to eliminate the gap?

 

[cjs 34]

You probably want to alter the "Support Z Distance" Setting to something closer zero and maybe also the "Support X/Y Distance" setting. If the PVA profiles works you may just want copy the values of those settings. 

[Tomasz_M 5]

Thanks, it sounds very reasonable. I went straight away to try your solution, however I could not replicate my problem... I get confused with this Cura profile/material policy, sometimes i do not understand its behaviour and parameters overrides. This time layers generated for BA support looks much better...

 

But it seems like it, Z an X/Y Distance is different for Breakaway and PVA profile and changing this parameters gives the desired results.

[cjs 34]

17 minutes ago, Tomasz_M said:

I get confused with this Cura profile/material policy, sometimes i do not understand its behaviour and parameters overrides.

Yes it's really confusing at times  Hopefully Ultimaker will at some point listen and rework the profile system to be more understandable and useable 

 

I just tried a few things in Cura. 

The difference between the PVA and Breakaway profiles is the Support X/Y Distance: PVA (0.2...) and Breakaway (0.8...) 

While loading in different models and looking at the generated support it seems like the Support X/Y distance doesn't work properly. When I set the Support X/Y distance to zero there is still a noticeable gap between the model and the support. @ghostkeeper may it be possible that you could have a look?  

[cjs 34]

Update: Did find the Setting: Minimum Support X/Y Distance. This setting seems to affect the support X/Y distance even though the description says otherwise. I'm honestly a bit confused by all the support distance settings (Support X/Y distance, support Z distance, support stair step height, support join distance) and do not understand the purpose they all have.  

[ghostkeeper 105]

3 hours ago, cjs said:

Update: Did find the Setting: Minimum Support X/Y Distance. This setting seems to affect the support X/Y distance even though the description says otherwise. I'm honestly a bit confused by all the support distance settings (Support X/Y distance, support Z distance, support stair step height, support join distance) and do not understand the purpose they all have.  

The way that this works (or should work) is as follows:

• If Support Distance Priority is set to "XY Overrides Z", then the X/Y distance between support and model should always be held, even if this causes the vertical distance to be larger than the Support Z Distance settings. The Support Z Distance is essentially just how far it must move the support downwards after computing the support with proper X/Y distance.
• If Support Distance Priority is set to "Z Overrides XY", then the Z distance between support gets precedence so it should always be correct. EXCEPT in parts with a fairly vertical slope, because then this would cause the X/Y distance to be very small. If the horizontal distance becomes very small, the Minimum Support X/Y distance kicks in and that gets precedence again so the vertical distance may still be larger than the Z distance.
• Support Stair Step Height is separate from all that. At the bottom of the support where the support rests on the model, the support is sort of stepped so that it doesn't rest on the model everywhere. This makes it easier to break off from the model, and improves slicing speed a bit too.
• The Support Join Distance is also separate from all that. If two pieces of support are very close together horizontally they get joined together. This prevents having lots of very thin pillars of support in favour of creating one bigger pillar which is stronger and prints faster too.

[Tomasz_M 5]

Hi everyone, thanks for help.

 

I would like to report that I was able to achieve the desired result by changing settings described above. I've tried 0mm Z distance and 0,3mm X/Y distance, and got perfect prints. However if I would print larger object, with large flat support areas, I would increase these values in order to break off the support easier.