Deformation of base surface
Hi All,
I am new to 3D printing.
I have a Bambu Lab H2D printer with an AMS. I am using the default Studio settings (with the exceptions stated below), and Bambu Lab PLA filament. The filament is dry.
The only settings I changed in Bambu Studio are:
Layer Height: 0.09
Ironing: Top Surfaces
Support On – Tree Structure
The reason for these settings is that I am trying to get the smoothest and most accurate (to spec) model I can. An accurate reproduction of the small pegs on the model is important, as this is crucial to the functionality of the model.
Everything runs well, except for the deformation of the model’s base. These defects can be seen in the attached photos.
Things I have tried:
Using a smooth plate, as this issue was first detected using the textured plate. Adding Bambu Lab glue to the plate (made no difference, but it was a bugger to get the model off of the plate).
I plan to upload this model to Maker World, so I want to make sure that the finished version matches the spec as accurately as possible.
There are two more pieces to this model, a cover plate and a draw. These printed perfectly and fit well.
Any suggestions as to how I can resolve this issue would be greatly appreciated.
Thanks,
Ken.
It’s not really clear what you’re saying the problem is. The print results pictured aren’t perfect, but they don’t look unusual. Maybe circle the specific areas you’re concerned about and repost the photos…
That being said, there’s more general feedback I’d offer… It’s important to understand that FDM 3D printing has limitations when it comes to dimensional accuracy. Even if the extruder’s path has no error at all, the print itself is going to change size/shape as it cools. Depending on the plastic and extrusion temps, potentially by a significant amount.
You can’t design for the same tolerances you’d expect from a CNC or a laser cutter (or a SLA 3D printer). You need to design for much looser tolerances.
When I need a really accurate print, I print it slightly “oversized” and then machine it to target dimensions with my CNC.
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How many bottom layers are you using?
Also, I know this sounds like a broken record but…have you cleaned your build plates lately? Dish soap and warm water, not IPA. It looks like it may be an adhesion issue.
One other thing is try a different infill pattern.
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The Bottom Shell Layers setting is set to 3.
I do like the idea of a different infill pattern.
I am Mr. Clean (but with hair). I clean my plates with Dawn and warm water after every print. It may seem excessive but given that just this component is a 23 hour print, I like to err on the side of caution.
I did read on Stack Overflow (in response to another person’s issue), that it may be worth experimenting with the Initial Lay Flow Ratio.
What do you guys think?
Photo #1 shows the base with the deformations. The other photos show the deformation, close-up.
You stated you are using 0.09mm layer height which is pretty thin for only 3 bottom layers. There is also a setting for the minimum bottom shell thickness which can override the bottom layer count. What is your initial layer height?
Since it is such a long print and the issue is with the bottom layers you could experiment with just letting it print the first ~5mm to see if your changes are helping.
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The 0.09 layer height was chosen as it seemed to be the best setting for accurately reproducing some pegs (2.998 mm) which protrude from the project (not pictured). I could be wrong about this of course. Perhaps there is a better way to do this.
The Bottom Shell Thickness is set to the default value of 0. The Initial Layer value is set to the default value of 0.5 mm.
What settings would you recommend changing prior to a test print?
Thank you so much for your help.
You should enable variable layer height. The slicer will adjust the top layer to be dimensionally accurate vs. rounding to the next full layer. And your print will go a lot faster because most of the other layers are probably going to print at much higher layer heights = much fewer layers to print.
Very thin initial layers are hard to do. Even the slightest irregularities in the build plate surface will result in defects like thin areas, or tearing/dragging of underlying layers.
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Thanks. I will give that a try.
@RocketSled beat me to the response.
Also, I think/hope you got the initial layer height confused with the initial layer width. The initial layer height default is 0.20mm.
Hopefully the bottom shell layer count is set to 7 or 8.
If you follow @RocketSled’s advice the top and bottom shell settings will change based on the layer height used. His recommendation should speed up the print and solve your issue.
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Thanks guys. I tried the Variable Layer Height, and the quality improved greatly. Still an issue with one corner though. Printing only the base has helped me to get a better look at what is going on. The print time went from 22h 55m to 15h 4m.
The settings I changed were: 1. Clicked Adaptive button. 2. Continuously clicked the Smooth button until I got the smoothest image I could see in Bambu Studio.
As you can see in the last photo, the overall results were better. There was no deformation on the left-hand-side.
I was thinking about increasing the Radius (3) to get better results. What are your thoughts?
Glad you are making progress. You can move the little triangles for quality/speed and radius to alter the results as well.
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Thanks Guys. I really appreciate your help.
Finally obtained a perfect print.
Resolution details for others experiencing the same issue:
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Changing the Variable Height as suggested by @RocketSled.
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Changed the Adaptive settings (see screenshot above). Clicked on (1). Clicked 5 times on (2). Changed (3) from 5 to seven (the clincher). Thanks @blchandl2.
I hope this helps others.
Regards to all,
Ken.
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