X2D Ironing Calibration Report
Introduction:
I started 3D printing with a Bambu Lab A1 more than a year ago. Everything went very well and I was able to achieve perfect ironing. Recently I sold my A1 to upgrade to an X2D. I deeply regret that decision, mainly because of the ironing quality.
I have tried every possible way to configure it but I cannot get there. So far I have used about 500g of filament trying to configure a setting that seems impossible to configure.
I am frustrated not to get the same perfect result I had with the A1, especially since this printer is supposed to outperform it in every respect.
1 My current setup
Printer: Bambu Lab X2D
Nozzle: 0.4mm standard
Plate: Cool Plate SuperTack Pro
Layer height: 0.2mm
Filament: Bambu PLA Basic
Firmware: up to date
Regarding filament, I always use Bambu Lab PLA, dried using the AMS 2 Pro.
Note that all calibrations were done with Black PLA Basic.
2 My ironing on my Bambu Lab A1 and how I calibrated it
For this test, back to the stock Bambu Lab filament profile (without the personal adjustments accumulated so far), in order to get a neutral reference.
Test done with the MakerWorld model “Ironing Calibration Speed & Flow 15-40mm/s, 10-50%”.
Result : 35mm/s at 30% flow — excellent, reproducible result, regardless of the surface size tested.
The lines are barely visible to the naked eye, and the surface feels “mirror”/smooth to the touch.
1 Result of the same calibration on my X2D
To calibrate the X2D I used this model: Ultimate IRONING Calibration Test - Free 3D Print Model - MakerWorld
As well as this model: Ironing calibration - Free 3D Print Model - MakerWorld
And here are the results
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Result: no surface is truly smooth. The areas that look correct in the photo actually show the underlying solid top layer pattern “showing through” the ironing pass — the ironing does not fully cover the existing surface texture, even on the combinations judged best in this test.
2nd test (printed in black filament)
Result: many areas show noticeable under-extrusion.
2 My filament calibration
2.1 Temperature
Determined using a temperature tower, within the filament’s recommended range (190-240°C per manufacturer specs); value retained: 220°C.
2.2 Flow ratio
Calibrated with the MakerWorld model “Improved Flow Ratio Calibration v3” (jimcorner).
2-pass method:
Rough pass: 7 values tested (1.12 / 1.08 / 1.04 / 1.00 / 0.96 / 0.92 / 0.88), filament flow ratio set to 1.0 during the test, identifying the threshold where the “raised half-circle” artifact appears
Fine pass: 7 values tested around the rough value (multipliers ×1.03 to ×0.97), filament flow ratio set to the rough value found, final value retained = the 2nd raised half-circle identified (from lowest to highest)
Result: 0.97x1.03= 0.9991
2.3 Pressure Advance (dynamic flow)
Calibrated with Bambu Studio’s built-in test pattern, step of 0.001, selecting the value giving the sharpest corners with no bulging or under-extrusion at direction changes.
Result: 0.027
2.4 Top surface
Refined with the MakerWorld model “Advanced Top Surface Guide”.
Here are the settings used for the other tests, as well as in my regular practice:
Top surface line width: 0.32 mm
Top surface pattern: Monotonic line
Top shell layers: 6
Bottom shell layers: 3
Solid infill pattern: Monotonic line
Top surface flow ratio: 1.01
Top surface speed: 65 mm/s
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Result: great look and very smooth to the touch.
3 Calibration on the X2D with calibrated filament
I used the same model so the results would be comparable.
Result: uniformity improves somewhat, but this is clearly still not it.
The best result appeared to be 30mm/s 10%, despite a slight under-extrusion mark.
4 Calibration refinement protocol
Methodology used: one parameter changed at a time, 4 values tested around a starting point, then refined ±0.5 step around the best value found.
Order followed: line spacing → speed → flow.
We start from the slicer’s default settings, which are also my best result so far: 30mm/s 10% 0.15mm.
4.1 Line spacing
4.1.1 1st pass
We will test: 0.11/0.13/0.15/0.17/0.19 (0.15 serving as a reference)
0.11
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0.13
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0.15
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0.17
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0.19
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4.1.2 2nd pass
The best value appeared to be 0.15mm, so I continued the protocol with: 0.14/0.16
(Unfortunately I lost the 0.16 result)
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4.2 Speed
For speed as well, we proceed in 2 passes
So with 10% flow and 0.16 mm spacing. We will test: 20/30/50/60 mm/s
Yes, I made a mistake — it should have been 40 mm/s tested, not 30 mm/s.
20
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30
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50
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60
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Result: the best rendering was at 30mm/s; at 20 mm/s the result was not acceptable, so for the second pass I chose to start from 30 mm/s with a step increase of 2 mm/s.
4.2.1 2nd pass
So 32/34/36/38 mm/s, still with 10% and 0.16 mm spacing.
32
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34
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36
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38
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Result: 32 mm/s appeared to be the best (dust is visible here since this part was used extensively across several environments to compare results — “it has lived a life”).
Important point: there are lines, like shadows, that are consistently present in the same locations on the model.
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This is the main issue with my ironing.
On the surfaces circled in green, I get very good ironing — smooth and glossy — but on the surface hatched in red it is matte and rough.
Regardless of the settings used, the lines are always in the same places, and the surfaces are also consistently degraded in the same places.
The goal now is to eliminate these lines and fix the center surface.
4.3 Ironing Flow
Only 1 pass, since the other results were clearly not good.
So keeping 32 mm/s and 0.16mm spacing, testing: 11/13/17/19%.
11
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13
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17
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19
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Result: 13% is the best — the result is the most uniform, the surface of the top triangles is smooth/mirror-like, and the shadows are the most subdued.
(19% looks better in the photo, but its surface is much rougher, the shadows are much more pronounced, and I did not get a good surface on the top triangles.)
4.4 Temperature
At this point I was looking for solutions and thought there might be a fusion defect in the ironing because the temperature was too low. I read on forums that there can be a temperature difference between the sensor, positioned upstream, and the nozzle, which would be downstream.
So I ran a test increasing the temperature by +5°C and +10°C (i.e. 225°C and 230°C), keeping the same ironing parameters: 32mm/s, 13%, and 0.16 spacing.
+5
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+10
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Result: no clear improvement, and even the appearance of small defects: grains on the side near the top of the triangle. Probably related to the filament being too fluid.
I ran a test without ironing at 225°C
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Result : the rectangle looks similar to the one at 220°C. However, for the complex shape, the higher temperature slightly improves the top surface.
4.5 Shape
In my test series I also printed a rectangle with 2 fillets of 5mm.
T 225°C, 13%, and 0.16mm line spacing, speed: 12/20/32/50/70 mm/s
12
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20
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32
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50
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70
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Result: 50 and 70 mm/s show the best results. However, these shadow-like marks are still present. The best result seems to be 50 mm/s.
4.6 New MakerWorld calibration
I ran another MakerWorld calibration Ironing calibration: larger, speed & flow - Free 3D Print Model - MakerWorld
I calibrated with speed from 50 to 80 mm/s in steps of 5, and flow from 10 to 50% in steps of 5. T 220°C
The results of these tests are excellent and really match what I was looking for. I thought I had found the solution. They were so good that it was hard to decide on a value, but I chose 55 mm/s 15% and therefore 0.15mm spacing.
This confirmed another theory from the forum stating that this type of extruder struggles to handle low speeds. So I ran another series on the complex shape at 220°C, 55mm/s, 0.15mm, with flow increasing from 15 to 25% in steps of 1, then 30% to 50% in steps of 5%.
Why test flow? Because I noticed under-extrusion in the ironing layer.
15
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16
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17
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18
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19
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20
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21
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22
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23
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24
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25
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30
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35
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40
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45
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50
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Result: still no good results. My best results are around 20%, but still with under-extrusion and shadows constantly present.
5 Conclusion and request
5.1 Conclusion
Since acquiring my X2D, I have carried out an extremely thorough and methodical calibration effort to try to recover the ironing quality I obtained simply and reproducibly on my previous A1:
Full filament calibration (temperature, flow ratio, pressure advance) confirmed correct
Top surface separately refined, giving a near-mirror result without even using ironing
Rigorous single-variable refinement protocol on ironing (line spacing → speed → flow), with dozens of iterations tested and documented
Several community MakerWorld calibration models used as reference
Speed range tested: 12 to 70mm/s
Flow range tested: 10% to 50%
Several temperatures tested (220°C to 230°C)
Test with the pure stock filament profile, without any personal adjustment, to rule out any calibration bias
Despite this extensive testing, no combination of parameters has produced a satisfactory, reproducible result on normal-sized surfaces. The best results obtained still show visible under-extrusion, shadows, or a grainy texture — never the mirror finish I simply obtained on the A1 with standard calibration.
The fact that my top surface (without ironing) is already excellent, combined with the fact that no ironing setting across such a wide range comes close to matching the A1’s quality, leads me to believe the problem goes beyond a simple user parameter adjustment.
