P1S ironing issue

Bambu Lab P Series Troubleshooting
1

When asking for help, please provide as much information as possible about your inquiry.
This will help everyone to better understand your problem, and provide you with the best solution.

  • Detailed description of the problem
  • Printer model used
  • Slicer settings used
  • Type of filament used
  • Photos that clearly show the problem
  • .3mf file (if the file can be shared)
  • Any potentially useful information that is related to the problem

What could be causing this ironing issue?

P1S w/AMS

Top surface ironing, rectilinear

Speed 30mm

Flow 10%

line spacing .15

inset .21

Using a .4 hotend with Bambu PLA

At first I thought the hotend was clogged so I paused the print and purged it. It purged fine, but when I hit play, it started printing the same way. Sorry for the grainy pic, it was still printing when I took it. It’s almost like the filament was skipping? I’m fairly new to 3d printing and have never seen this before. Unfortunately this happened at the end of a 7 hour print. 200+ grams of filament wasted.

iron issue
iron issue513×513 32.7 KB

2

Some general thoughts on ironing: Did you calibrate the flow rate beforehand? That’s almost essential. For every filament, every color.

Then you have to calibrate the ironing, which is also important. Again, for every filament, every color.

And make sure that the filament is dry, and also select a high-quality profile as a basis, for example.

Screenshot 2026-02-16 183540
Screenshot 2026-02-16 1835401590×636 45.6 KB

Now specifically regarding your case: You should also make sure that your nozzle is clean. This is difficult, of course, with such a long print. You could insert a pause before ironing and check and clean the nozzle again. The printer then pauses and moves to the park position until you confirm on the printer that it should continue. Normally, this isn’t necessary, but it could help in your case if the previous tips above don’t help.

Screenshot 2026-02-23 174527
Screenshot 2026-02-23 174527802×524 33.5 KB

3

Thanks for the info. I had no idea about calibrations so I’ll look into that right now. I really do appreciate the help. At my age, I don’t have years to learn all this stuff.