Problems with bridge infill. Model snaps at that point when put together.
Can someone help me with my settings, I have tried all the settings that I can think of to get rid of the bridging occurring in my screenshot;
It might not seem like a lot, but these are at two layers and are a real problem for me, when putting pieces together and fitting it with screws around my intended target it snaps at that point.
If someone could download my 3mf file and tell me what to do I will be forever grateful.
Best Answer by Neophyl:
Where exactly is it snapping ? Can you post a pic of the part where its snapped ? BTW thanks for attaching the 3mf file.
I take it there are 4 bolts that go through the posts and attach with nuts on each end ?
Given the project settings I notice the Addnorth petg has a temp range of 240-250 and you are using 240 in your filament profile. If the layer to layer is weak then up your temp to the top end of 250 or even slightly higher and try a print.
Another thing you could try is up your perimeters to 4 and knock your infill % down from 100 to 20%. I know that may seem counter intuitive but perimeters get more strength than infill and if you look at the layer preview the posts get a better layout of plastic with perimeters set to 4 and the top and bottom of your parts should be plenty strong enough still with that infill % given the design and where it gets placed.
RE: Problems with bridge infill. Model snaps at that point when put together.
Oh, using PS 2.2.0+
RE: Problems with bridge infill. Model snaps at that point when put together.
Where exactly is it snapping ? Can you post a pic of the part where its snapped ? BTW thanks for attaching the 3mf file.
I take it there are 4 bolts that go through the posts and attach with nuts on each end ?
Given the project settings I notice the Addnorth petg has a temp range of 240-250 and you are using 240 in your filament profile. If the layer to layer is weak then up your temp to the top end of 250 or even slightly higher and try a print.
Another thing you could try is up your perimeters to 4 and knock your infill % down from 100 to 20%. I know that may seem counter intuitive but perimeters get more strength than infill and if you look at the layer preview the posts get a better layout of plastic with perimeters set to 4 and the top and bottom of your parts should be plenty strong enough still with that infill % given the design and where it gets placed.
RE: Problems with bridge infill. Model snaps at that point when put together.
@neophyl
I will post a picture tomorrow, if I can find it. It did not break between layers but across a few layers. I will also try your suggestions tomorrow and get back with results. Previously I have gone through temperatures from 230-250 and settled for 240, but that have been on other printers. This is printed on a MK3S, maybe should have told that.
Regarding those weird bridge fillings, is that a bug? At least in theory that is a weak spot.
Thanks, I’ll get back after a good nights sleep 😴
*edit, it snapped approximately where those bridge fillings where
RE: Problems with bridge infill. Model snaps at that point when put together.
@sw3de
I run AddNorth at 245 - 245 (First layer - Other layers) on a Prusa I3, Bed at 90. Thats the settings I have settled at. I usually get good prints with AddNorth except for first layer issues, but after learning that regular cleaning with soap and water is preferred after PETG prints I have not had any first layer issues.
Regarding strength, trade perimeters for infill. Perimeters provide much better strength than infill. Here is an example of a strong part printed with AddNorth PETG. The part can bear the full load from the quick clamp
RE: Problems with bridge infill. Model snaps at that point when put together.
@neophyl
Adding more perimeters made it look good in PS just like you suggested. Printer heating up now as we speak. Looking very promising.
Added two pictures, the model to the left i used excessive force to see when it broke, the one to the right snapped when screwing the parts together with the intended goal in between. gosh, terrible formulation but I can't get it any better. The part to the left I almost couldn't force to split at all. The one to the right maybe had one layer separation but the other is definitely cross layers. I will have to try and up the temp but when I saw how it was sliced and then it snapped at that point (which in it self already is the weakest point) I focused my attention on those two layers.
The printed parts are to be clamped with a pressure gauge in between them that are 17.9mm. I made the models to have a space of 17.6mm so that they would sit tight enough. When screwing that last bit together was when it snapped. I now have increased the space to 17.75mm instead which I hope will be tight enough and ease the stress of the printed parts when forced together by the screws.
Thank you for your input!
RE: Problems with bridge infill. Model snaps at that point when put together.
@ernelli-m
Thanks for your response. Good points!
May I ask where you live? I'm curious how widespread addnorth's filaments are. I like their filaments a lot and have been printing exclusively with them for the past year and a half and mostly with PETG.
RE: Problems with bridge infill. Model snaps at that point when put together.
@sw3de
I live in Stockholm. I have settled on AddNorth since it is a very good PETG filament and can be sourced at Kjell&Co.
I mostly print functional mechanical parts so the aesthetics is not of any concern opposed to figurines etc.
I started with a Prusa PET filament spool that I got with the printer, but realised that I needed a more stable source, preferably in retail stores. Changing filaments is cumbersome since it requires testing and adjustments. When I started with AddNorth PETG I was running at 250 deg, but lowered that to 245 deg to improve bridging and finish.
I have never printed any temp tower, maybe its time to actually do some thorough testing after more then a year with printing, and iterate all possible options regarding printer/filament settings. But I spend most of my time with CAD/construction/design so as long as the printer produces adequate results I'm fine.
I have a fairly efficient tool chain consisting of FreeCAD -> PrusaSlicer -> Octoprint. I even wrote a macro in freecad to automate the STL generation in one click.
I have som ideas regarding writing processing tools between FreeCAD and PrusaSlicer so that printing decisions can be designed and controlled from freecad such as details->layer/height , strength->perimeters/infill.
FreeCAD is a very versatile CAD system that can be fully programmed, although it has a steep learning curve and it sometimes crashes, but its Free and in my opinion worth the investment in learning time.
RE: Problems with bridge infill. Model snaps at that point when put together.
@ernelli-m
Then we're almost neighbors, I live in Undenäs, its only about 25 kilometers 😉
I'm also very pleased with addnorth, I started using it a couple of years ago while still printing mostly PLA, I used to buy Colorfabb at that time but noticed addnorth and the fact that it was made in Sweden. I really liked their PLA and then went on to PETG. After learning the real importance of the first layer and offset I almost exclusively use PETG now. I order it from their website because we don't have any stores at all that are close.
I first used it on my Ultimaker with a flex plate and PEI sheet from Buildtak, it worked perfect without any cleaning and wiping, then when I bought my first Prusa (MK3S) I was made aware of another use for dish soap.
I have almost no knowledge in programming så Freecad isn't anything for me but I can see why people like it, and it's sounds like a good idea you have to make settings in Freecad that fits the printing purposes, good luck!
Me uses Fusion, have converted to PrusaSlicer and then Octoprint. Mechanical parts are what I do most but also some organic models that my wife paints.
Ha en fin dag!