Hi everyone, I have to print a piece in pa12 (fiberlogy), I’ve reached the right setting for the material(incredibly strong and really usable for making final use product) but I need to support my piece and with the same material (without using any support specific material) I can’t find any good result (with higher top z-distance value(0.24 with 0.2 layer heigh) very bad looking overhang and with Lower top z-distance value(0.16 with 0.2 or 0.16 layer height) the support are impossibile to remove. So I’ve tried with SUPPORT-G material and with HELIOS form formfutura, both are great, the support can be easily removed but the increasing of layer time that using support material inevitably bring make the piece extremely brittle and unusable.
I never noticed something similar with PA. What happens to PA12 to become brittle?
Sorry, I came here with questions and not solutions, but you already evaluated the best options for your case. An undesirable solution is a redesign. You may also have some margin for improvements in the slicing process, but you know it better.
Fist of all thanks for the attention, don’t worry every experience are useful, even with other question
I think that pa and pa12 can be assimilated for this problem.
The bad news is that the pierce is a 3d scanned file with no many way for redesign it.
That is a really limit for fdm, because the material characteristics can be compared to an sls printer piece.
I’m not certain what you mean when you say that the part becomes brittle if layer time is increased. Do you mean the layer above the one containing support interface ends up delaminating because the PA part of the support interface layer gets too cold for proper layer adhesion?
The OP may mean weaker. As you change filaments, you overcool the previous layer which will lead to a weak Z adhesion. Not to mention, the one nozzle printing method of the AMS will also contaminate the base material with trace levels of the support material and being they are not compatible (thus the reason it is easily removable), this also makes the base part weaker.
Double whammy.
You can mitigate the second problem of contamination by elongating the purge amount, but this makes the first problem worse by taking longer to compete and allowing the plastic to cool even further.
Definitely seems like a “rock and a hard place” if there ever was one. Personally, I would suggest going back to the basics. Support it with the same material, just tune the support as good as possible.
Things that I would suggest:
Increase the X/Y distance setting. I normally don’t use anything under .50 mm. The stock .35 mm is too close for me. It can merge to the base model and make removal very difficult. You do need to assess your model as it is possible to go as high as a mm or 2mm and have a good result but fail to support an adjacent section. My setting range is .50mm to 1mm. I don’t find I need to go over 1mm and their is never a case where I worry about a 1mm gap being bridged. But again when using large gaps be aware of the adjacent areas to make sure the X/Y distance didn’t create a problem with a section that needs to be supported. I would suggest starting with .5mm and going up.
Also review the Top Z Distance, the tighter the Top Z Distance the better the finish, but the harder it is to remove. Generally, start with the default and add a .1mm until you are happy.
Support style, “Snug”. I love Snug supports as it takes less time to print and tries to remain within the confines of the model. Being they are a tighter fit, they tend to not blend into the model, so it works well hand and hand with the X/Y distance.
I’m sure others have even more options and can chime in. One other thing I do a lot is limit the supports with the painting tool. This means I use a lot of bridging in my supporting, but it works well for me.
I mean if the time between one and the next one of pa12 take too much time, like if the machine has to change twice the filament for print the support interface with support material, the overall strength of the piece is compromised and it become very brittle
Thank a lot for your incredibly articulated answer, your are great, if in this community or in the forum would be more people like you, most of the problem could be solved in a click.
After this I’ve already modified some of the setting with the one that you have suggest and I add some of your advice and I’ll try this night, one with same material support and another piece with interface print with support g, I’ll post po tomorrow the result, waiting for the new bambu printer
Thanks again
In Bambu Studio, add a modifier, scale it to the thickness of 1 layer, place it at the required slow layer, switch to object settings and change the speed for the modifier. Verify the speed does change by slicing and selecting “Speed” from the drop down menu (top right). I would post screenshots of the steps but currently away from the desk
I understood but never experienced it, as I never had to use support with PA.
From what I understood, I can imagine “delamination”, which will weaken the print.
What I didn’t get is if you use the support material for full support or as an interface.
If the latter, I would try @Organicactus advice and use a modifier to print hot (if you still have margin) and slow in the critical zones. You may also need to tweak the flow rate. Depending on the print geometry, it may be an extreme challenge or impossible to do this; also, I would recommend tests as you may expect inconsistent layer dimensions and an odd look.
