SOLVED: Random Extruder Retraction Issue Causing Print Failures


I am experiencing issues with the extruder. When I launch prints that require a high extruder load, it starts to lose steps, and the print is very bad. Has anybody else experienced something like this?

This can be noticed when printing the high-speed Benchy that is included on the SD card. Attached is an image of the first Benchy printed when I took the printer out of the box a month ago and the latest print I have done with the same filament.

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Bit vague.
Exactly what filament is it? Hopefully not the Support PLA.
If not how often do you use this filament and how was it stored?
Have you tried other filaments with this Benchy file?

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A bit vague? :joy: You sound like Dr. House. Okay, okay, sorry, you are right.
I tried printing with basic PLA and mate PLA, but encountered the same issue. Another day, I attempted to print with TPU A93, and it was impossible. I suspect the cause is related to this. The extruder doesn’t push the filament due to the minimum gap or distance between the extrusion wheels being too large. In the following, I’ve attached pictures of the extruder’s wheels with and without filament. As you can see, there’s likely a difference of around 0.2mm between them.

Not experienced with the A1 extruder but it does look out. If you’ve had it apart, it doesn’t sound like you can see anything broken. Is the screw for the spring tension all the way in? Other than that, I’d suggest starting a support ticket.

It is not physically possible to bring the wheels closer together in any way, even by completely disassembling the extruder unit as shown in the pictures. My solution is to design a new lever wheel (or use another one that another user has designed), print and install it, or replace the entire extruder unit.

Why? If there’s a problem with the extruder, wouldn’t the best route be to get the faulty part to be replaced under warranty? I don’t see this being a common problem and even if it was, I’ve never seen a “mod” appear on MakerWorld.

I have submitted a support ticket; however, currently, the response times are significantly delayed and if I can temporarily resolve this issue and have the time to address it, I will do so.
I have attached two links:

So in other words you knew what you wanted to fix, and just wanted to promote a mod? meh…

What problem do you have? I’m asking and looking for other users with a similar issue. I want to know what the community thinks about my problem and share possible solutions if we have any. The spirit of a forum is to share. At the first moment of publishing this post yesterday night, I didn’t know what the problems were here. Maybe I’m wrong with my conclusions, and I’m waiting for more users with similar experiences and other solutions. Do you have any solutions or not?

Ok. I applied the hack, but the problem is still there.
I don’t know what to do now. The BBL support is missing.
All prints fail if I don’t reduce the speed, regardless of the material.

Here is a photo and a video captured during a PETG flow calibration.


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The nozzle appears to have retained TPU residue inside after several attempts at printing with it, causing the nozzle’s duct to narrow. The extruder has to exert more force, leading to extrusion issues. The solution involves cleaning the interior of the nozzle with a special cleaning filament or replacing the nozzle.
Does anyone have experience with this type of filament? (Cleaning filament)

Is that a manual calibration on a textured plate ?

Yes. Why? Is the standard PEI plate provided with the A1?


Is the calibration reliable?

It depends. There are a few cases that will make the calibration result not reliable:

  1. Using a texture plate to do the calibration ;

  2. The filament is damp, which will make the calibration result not suitable for fresh filament ;

  3. The filament is transparent ;

  4. The build plate is not sticky (please wash the build plate or apply gluestick) ;

Except for the above cases, the calibration result is reliable in our test.

how to start.

Thank you, :+1: I’ll keep that in mind for my next calibrations as soon as the high-temperature plate arrives.

I find the wiki is quite confusing. Because it’s not always clear what printer it is referring to. In my understanding the linked “Flow Dynamics Calibration” article is written for the X1/P1 series printers. They do have an optical sensor for flow analysation. This is why they are sensitive for the surface of the print plate and also for transparent filaments.
The A1 series printers introduce a new eddy current sensor for dynamic flow rate calibration. Reading the display info string while the printer is in preparation I got the impression, that the flow rate measurement is performed by extruding filament in the waste tray.
Anyway, I assume those tips above are not relevant. Except for the damp filament.

flow dynamics
Manual mode:** the user needs to judge which parameter to use by observing the quality of the calibration line on the printed board.
flow rate
By observing the calibration block, select the number corresponding to the calibration block with the smoothest top surface. After selecting, the corresponding flow ratio value will be displayed below.
Again another very interesting read.

i believe you are confusing manual and auto calibration (that little paragraph in bambu studio )