It happens that after a smooth piece with the final polishing option, and therefore the print ends with polishing the surface, the unloading of the filament is difficult and blocked, with the consequence that I have to force it and carry it out manually
You mean after ironing? I may have had that problem as well, without realizing it was related to ironing: I’ve had a number of strange retraction problems, seemingly for no reason. I had a look at my cutter but it looks like brand new after 1150h.
I’ll keep my eyes open for the possible relation to ironing.
Hi Raz,
Yes, I have done several tests and I can assure you that the problem exists.
You should think about adding a mini purge to the G-code at the end of the print, especially if the ironing option is enabled.
Keine Probleme bei meinen 3 P1S nach dem glätten. Vielleicht liegt es am Filament?
Uso il filamento PLA+ Sunlu
When I had problems and managed to force pull it out of the extruder, I saw signs of too high temperature above the cutter. Perhaps we should suggest to the firmware people that whenever a retract to AMS fails, it should try purging 10 mm before trying again.
Same problem here, I have to iron for 10-15minutes and after that when it try to resume adding layers its clogged.
Hi Luca, do you have a gcode for purging after ironing? when i print 2 objects (by object) on my buildplate, after ironing, the second objects first layer is really bad because of heat creep or something. i have tried to copy the initial purge gcode in text editor, and paste it just before it moves to the second object, but it will not purge. it is like it dosn’t read it at all and just skips it as if it wasn’t there.
Thanks alot!
Anyone found a fix for this? I’m printing something with multiple ironing layers, and I’m getting clogs after the first ironing layer is done. I’ve checked my nozzle and it’s fine, it seems to be caused by heat creep during the ironing layer. My print always fails after the first ironing layer and when I pull out the filament it’s bunched.
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I never really used the ironing as I am happy with my top layer quality as it is.
Just for the fun of it I did some tests though and can confirm that the ironing does not always work as advertised.
While this very tiny amount of added filament is great so smooth the surface, it is really bad for the hotend - or to be precise, the molten filament inside.
Two things happen here:
The heat creeps upwards in the hotend - not a big deal as it can handle it.
The filament also transfers heat, resulting the the filament getting soft higher up in the hotend.
Result is that the filament is compressed and increasing in diameter.
In my tests the issue was most annoying with a high print temperature while printing at a temp just high enough to give good layer adhesion reduced the effect.
The only thing we really need is enough heat to soften the top layer to allow whatever little is added to bond.
So I did some manual labour and edited the G-code to include a slight temp drop after the last layer.
Had the print temp at 228 and dropped it to 218.
Still a smooth surface and the next object had no clogging issues, first layer came out fine as well.
I have to say so that I used a brim and that for this there WAS a slight extrusion issues for the first 2 loops.
Adding a good purge after ironing if there is more to print would certainly be beneficial to have as an option in the slicer…
Have you already found a solution to the problem? I would hate to experiment with the G-code as I have absolutely no idea. But it seems to me that ironing causes heat to build up because the nozzle moves so slowly. Does anyone have any ideas about this?
I’m also having the same problem, everytime i ise ironing, i jave to unmount the entire head to clean, is all new and looking good, if I don’t use ironing goes everything well. I need to check but seems that this started after my last update, can be just a coincidence but I’ll check the release notes to see if they changed something related.
Maybe this can help:
How fast are you printing the model itself?
COULD you LOWER the extrusion temp without loosing layer adhesion? 
The problem is that Bambu did provide an option to set a nozzle temp for the ironing.
I like properly calibrated filament and have no real need for ironing.
But if I do I face the problem that even for a flow rate of 10% there just isn’t enough gaps on the surface for the extruded filament - it builds up!
Not just that: As the flow is so low the filament gets overcooked, totally ruining a shiny filament…
The only half working solution is to edit the G-code to include a lower extrusion temp for the last and the ironing layer.
Sadly we can even do this through the slicer 
Same for the fan control.
IF we could crank up the fans to max for the ironing layer the heat creep issues could be minimised.
The mess and clogging AFTER the ironing could also be avoided.
All we would need is a little purge run before doing the shutdown procedure for the head.
A cm or 3 would probably be enough to push the cooked filament out so extruder and heatbreak have COLD filament…
Since I swapped for the E3D I no longer suffer from those issues.
But that’s what I did with the Bambu hotend:
Reduce the overall print speed for models with large ironing surfaces - like plates or such.
Not ideal for large models that already need a few hours but there is always those speed buttons.
The key here is to have a nozzle temp just high enough to let you print without problems.
Simply hit the speed button for the ironing layer and you might be surprised to see that faster ironing often produces a better surface.
The hardcore way:
Slice the model…
Then for the layer with the ironing do a right click on the green dot and select add custom g-code.
Here you can add the code to reduce the nozzle temp and even add a pause (don’t forget the z-lift).
The Wiki and Marlin references should get you the codes you might want to try and play with.
Ok but how the heck do I find the right syntax and such?
Ever noticed the bottom slider in the preview ?
Try it…
Most of the G-code is commented to get a clue of what it does.
G29.1 Z-0.04 - for example sets things for the textured Pei plate…
M104 S225 sets the nozzle temp to 225 degrees…
The preview is not always ideal to find the codes so try a normal editor like Notepad++ on some exported G-code to note down what you want to play with.
i had this issue to and with ironing set to top surfaces not just topmost surfaces it clogs the hotend mid print , it only does this for long ironing surfaces like 15cm size of object or something , had not luck to fix it somehow , the ironing is so much better ugh but had to disable it for big objects
Perhaps too much filament is being extruded. And the nozzle temperature also plays a role, as the previous speakers have already mentioned. You can insert a G-code after the model is ready to print. And lower the nozzle temperature from the ironing layers onwards.
Right-click on the green “+” dot and select Custom G-Code. M104 sets the new temperature with “S”. Here in the picture it is 280°C. You could add a break, but it’s not so nice because it can leave blobs on the print.
You can also set the speed and flow for ironing. If necessary, reduce the flow slightly or increase the speed.
You should be able to find a setting that works for you. However, reducing the flow (standard 10% when ironing) will result in the filament being extruded more slowly. A higher speed helps to extrude the filament faster, which counteracts clogging due to heat creep. So if the flow is reduced, the speed could be increased at the same time. So that the extrusion speed is maintained.
Best regards!