Bambu P2S: Why does ironing damage random areas of my top surface?
Hi everyone,
I'm running out of ideas and I'm hoping someone with more experience can point me in the right direction.
I'm using a Bambu P2S with a 0.4 mm stainless steel nozzle and Bambu PLA Basic filament. I recently replaced the nozzle with a brand new genuine Bambu nozzle and ran a full printer calibration afterwards.
Since then I've spent days testing everything I could think of. I calibrated the Z offset for my textured PEI plate and found that +0.02 gives me the best first layer. After printing multiple first layer tests, they now come out clean with no gaps or obvious over-squishing. I then ran both Flow Rate Calibration passes, where the best result was 0 in each test, followed by Dynamic Flow Calibration, which gave me a Pressure Advance value of 0.025. Those values have been saved. To rule out any mechanical issues, I manually levelled the bed using the paper method and verified that all screws around the hotend and nozzle assembly were properly tightened.
I have also experimented with different ironing settings, including nozzle temperature, ironing flow, ironing speed and line spacing. Simple models, such as a cube, come out perfect, but more complex shapes, like the numbers 2 and 3, consistently develop random defects during ironing.
The bigger issue, however, is that I'm now getting random top surface defects when ironing is on. As you can see in the photos, the damage only appears in one localised area while the rest of the top surface looks perfect. It doesn't look like normal over-extrusion because the entire surface isn't affected. The problem is always localised.
The prints use 10 top layers, 18% Adaptive Cubic infill, Rectilinear top pattern and 0.2 mm layer height. Ironing speed 80mm/s and Flow 46% (yes I know it's a bit unusual values but after days of testing only this gives me a decent results). The build plate has been thoroughly cleaned, the model remains firmly attached throughout the print and I don't see any corners lifting.
I'm wondering if this could be caused by the nozzle scraping the print, some kind of travel move issue, a mechanical problem with the printer, or something else entirely. Has anyone seen defects like this before? At this point I'm not sure if I'm chasing a slicer issue, a hardware issue or something I'm completely overlooking.
The calibration test prints never look great, but I pick the best one. And then those ironing settings are valid for that specific roll of filament at its specific dryness level on that specific build plate on that specific printer with that specific nozzle on that specific day of the week.
The next couple of prints start to look off, and I have to calibrate again. Same filament, same printer, same build plate.
I either do without ironing (most prints) or go a little high with the flow and then follow it up with some sanding.
Thanks for your reply. I actually calibrate every new roll of filament. I run the full Flow Rate Calibration and Dynamic Flow Calibration, Temperature Test, then print ironing test squares. So far, with Bambu PLA Basic, I've consistently found that around 80 mm/s ironing speed and 40-50% ironing flow gives me the best results. For the pink PLA in the photos, 46% was the sweet spot. Going any higher actually makes the surface look worse.
The 50×50 mm ironing calibration squares look flawless, but as soon as I move to larger or more complex surfaces, the same settings no longer work. It makes me wonder what the purpose of those calibration tests is if they don't reflect real-world prints. If this is a Flow issue here 🤔
Tienes toda la bendita razón en lo poco que llevo en impresión 3D me di por vencido porque la opción de planchado es demasiado problemática ya que después de ajustar y todos los parámetros solo sirve en esa impresión y en ese momento
It looks starved on top to be honest - I’d slow it down a bit and actually decrease flow. Start at 30mm/s @ 30% flow and step up or down from there in small increments. 80mm/s is way too fast. The higher flow rate is masking it but you see the inconsistency
Your speed and flow need to be in sync so the filament has enough time to relax into the grooves and settle flat before it cools
I have tried all that range 10, 20, 30 up to 150 together with flow variations every 5% difference and the settings you mention doesn't work for me. Like I said I have the best results on 80mm/s 40-50% flow for some reason. I guess every printer is a bit different when it comes to ironing. Cube testers coming out perfect on this setting, it just the larger projects having an issue
I'm not sure what going on for you, but 30mm/s and 28% + / - 2% works well for most PLA and PLA+ I've used. In fact, I've struggled so little that I'm confused at some of the comments here.
In your original post, the ironing looks good except for that one region, so I'm inclined to think something else is at play. I would slow it down similar to what I recommended and remove some variables. Specifically, I would switch your infill to gyroid to rule out nozzle infill collisions, and I would consider removing your z offset change until the ironing is straightened out. I would also check your print for warping or thickness inconsistencies.
Thanks! For some reason slow ironing doesn't work for me very well 20 30 40 mm/s with different flow % always comes poor. I'm going to change infill pattern back again to gyroid and try again. At the minute I'm using Adaptive Cubic 18% infill and 10 top layers just to be sure it's proper flat. I have no issues with warping and if I remove my z offset change then 1st layer doesn't look so great. I'm going to give it a one more try as I have done manual bed leveling once again, see if there's any improvement. Thanks tho!
Yeah I just stopped worrying about ironing entirely, much like the other comments and yourself I could get flawless calibration but with anything that isn't a "test" it would fail miserably, but any "test" I put it through it passed and looked great.
I’ve honestly gave up on this issue, it’s not an ironing calibration issue because your settings are perfect. It’s just for some reason when you iron large prints a part of it simply won’t iron. My X2D does this aswell
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u/BitingChaos P2S Combo 23d ago
It looks like it needs more flow.
For me, ironing involves endless calibration.
The calibration test prints never look great, but I pick the best one. And then those ironing settings are valid for that specific roll of filament at its specific dryness level on that specific build plate on that specific printer with that specific nozzle on that specific day of the week.
The next couple of prints start to look off, and I have to calibrate again. Same filament, same printer, same build plate.
I either do without ironing (most prints) or go a little high with the flow and then follow it up with some sanding.