Hello everyone,
this is my first post. I had an Sovol SV06 before and now switched to the Bambu P1S Combo.
I derived the Filament from “Bambu PLA Basic” in the Bambu Studio, and set Temperature to 210 Degrees. For high speed printing the filament is supposed to be 200-220.
After a few small test prints I calibrated flow dynamics and flow rate for my used filament, the “Jayo PLA Meta”. K=0.025, and flow ratio 0.98
I printed this model: just another poop chute by zinssmeister - MakerWorld, the first profile.
This is the whole print. What looks strange to me is that the pattern of the wall is different in a straight line, where the hole is (see arrow)
And I have go some not very nice things in the print like this: Is this over-extrusion?
Here is the second spot, and also the floor could be a little better.
So I am guessing this is over-extrusion and an easy fix could be to print with a slightly lower temperature Like 200 degrees?
What test print would you recommend to fest these problems when trying to fix them?
Thank you very much!
Welcome to the forum.
The straight lines you are seeing are caused not by over extrusion but as a result of either bridging artifacts or differences in speed in that particular area. You can try to dial them out with slicer settings or by turning down your printing speed.
The bottom floor roughness can be solved by really dialing in your filament calibration. Use the calibration tab in Bambu Studio.
I would not lower you temperature as that will cause other issues.
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Check the preview in the slicer 
There you can see the speeds applied and the flow rate.
In almost all cases you will find difference where you printed model shows flaws.
As Jon pointed out above a properly calibrate filament and finding the best settings is key.
If you want perfect prints the easiest way to do this is by making sure the entire model prints at the same speed.
Only problem is that layer times can still vary badly.
You face two different problems you need to address and solve:
- The filament calibration, preferably based on solid infill test prints.
- The time the filament spend in the hotend.
Number one should be obvious, same for the fact that changing the print temp CAN affect your calibration results.
Number two though can be a pain like the real one
Let me try to explain the problem:
If you set 220 degrees than this is based on the max print speed.
Meaning the flow properties and actual temperature the filament comes out differs with the extrusion speed.
This can be quite obvious when printing with a rather low temp and using infill combination.
Checking a testprint then often reveals those infill lines did not really bond much with each other.
A combination of time, temp and the fact that the plastic extrudes onto just a single line.
Thanks to the extruder working overtime to get the infill out the plastic does not reach the same higher temp it reaches when doing those slow outer wall loops…
Getting the flow rate and print temp just right fixes a lot of surface issues.
Getting the flow rate as constant as possible throughout the print gives the best result.
Another and often overlooked factor is the pressure inside the hotend.
Sparse infill of low density usually translates to low pressures.
On the other hand gap infill or top layers can result in rather high pressures.
It is the capabilities of the firmware and slicer that (try to) ensure we won’t encounter things like going through big pressure differences too fast.
No matter how good these measures might be:
The fast you print the less wiggle room is left to allow the pressures to adjust without causing over- or under-extrusion.
A thing I really miss is the option to change all print speeds based on a percentage.
The slider to go from silent to insane is a nice gadget but makes it VERY hard to create print profiles for complex models where these issues are known to create nightmares…
Even better would be a proper ramp up and ramp down option.
Dependinging on the filament needs you could then just set a value that ensures the printer won’t jump from fast to slow but instead slows down slowly and speeds up slowly…
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