Dear all
Recently I had to print some complicated parts which involve support. I ran into a few issues which need to be solved.
I was in contact with Bambulab and they confirmed they are working on it, but it is unclear regarding priority / time frame.
To understand how big the pain is for the community, I would like your feedback.
Did you also encounter the issues I describe in the following section? Do maybe have something to add?
I use support only with an interface layer from a different material. The interface layer is roughly 1mm thick. It should work with printing PLA and using PETG as interface layer or vice versa.
For me personally the AMS is a game changer because it allows to use different material for the interface layer. As a result you can get perfect surface finish even for complex parts, which was impossible before. However, at the moment the reported issues will make it impossible to use the full potential!
I hope for support of the community to get the software improvements as soon as possible!
Issue 1) XY distance
All distances should be set to 0 for interface layer but not for the rest of the support. This is currently not possible since XY distance can not be set independantly.
More information can be found here: X/Y Support Distance Priority Ā· Issue #2529 Ā· bambulab/BambuStudio Ā· GitHub
Issue 2) Missing bridging
Because of high material change times you try to minimize the amount material changes. Therefore, you only use support where it is needed. However, if done so, Bambulab Studio does not do any bridging layers for sections where no support shall be used. Since it does not make any sense and I can not change it, I call it a bug.
I have explained the phenomenon here (Bambulab Studio sections seems a bit sparsely populated): Support blocker results in missing Bridging layer in Bambulab Studio
Issue 3) Needless bridging
I have realized that Bambulab Studio in some cases does insert a bridging layer even though support is used with z-distance 0 and an interface layer. Because of the reduced material flow the layers even bond together with different material (PLA/PETG). The result is you can not or only hardly remove the support.
Unfortunately I have no picture to show this issue. I dontā see any reason why bridging should be done when using support with an interface layer. Itās maybe not a āreal bugā since the layer makes sense when using the same material for support. In conjunction with a different material however, it really is not working.
Edit:
Issue 4) Support Interface Speed
(thanks @ Verkinix)
Support Interface Speed affects layer BELOW instead of ABOVE the material interface change.
The support interface speed appears to apply only to the layer BELOW the support interface rather than ABOVE the material interface. As it pertains to PETG/PLA, the material change will āslideā or āstringā if itās going to fast on TOP of the interface change. Adding a control to control the speed of the material change layer ABOVE the interface would be a nice addition for situations like this.
Issue 5) Flushing volume for filament change
If the flushing volume is not high enough you basically make a predetermined breaking point by design in the layer of material change. I did some testing with a testpart and I had to increase the flushing volume to at least 500 mm3 to not severly alter the mechanical properties. In some cases even more might be required.
The current matrix with flushing volumes are meant for color changes, but not material changes. I would therefore propose the following:
- Give the possibility to have a flushing volume which is greater than 999 mm3 (current max).
- Give a possibility to define flushing volume for changes of material type. For instance: if you go from PETG to PLA, it will not depend that much on the color. So, it would be more conveniant to globally set a min flushing volume for changes in material type.