Clogs on multicolor prints

Bambu Lab P1 Series Troubleshooting
1

I have a P1S with an AMS. The printer is only 2 or 3 months old. Most of the prints I have done have been single color but I have done a few multicolor prints. Over that past couple of weeks, every multicolor print I have done, the printer will print fine, cut the filament, retract it in to the AMS, bring the next one in, and tell me it’s jammed. Typically, I just tell it the problem is solved and it will try it again, repeat a few times, then it continues. Might get a couple more layers, might work for an hour or two, but then same thing.

It’s a P1S with AMS.

Bambu, Sunlu, Inslogic, Ziro brands of filament (does it on them all) PLA

Stock .4 nozzle that I have cleaned more times than I can count with the whole heat up the allen key, insert it from the back, heat up the nozzle, pull it out method that is on the Bambu wiki.

I’ve taken the extruder apart, it looks pristine still.

I have the AMS on a riser and the lid off, it does this with the door open and closed. It’s in the basement and I live in Michigan, there is a dehumidifier less than 10 feet from the printer. And this has been going on during end of winter and beginning of spring, so it’s pretty cool in the basement. It’s not an ambient heat issue but everything I read keeps saying “It’s heat creep because the area is too hot.” I even printed some spacers someone made to give better air flow over the heatsink specifically to eliminate heat creep. I’m so certain that it’s not an ambient heat issue as is evident from the side of my last print curling up on a brand new supertack plate, even while the extruder was getting jammed.

I did have a guide on top that the PTFE tube went through that was supposed to help prevent clogs and such, but then I see others talking about how that can actually cause them, so I removed it.

I have not changed the nozzle yet, that’s my next step, nor have I changed the PTFE tube yet, but I have checked both. I just switched off the printer during the latest clog mid print and am letting it cool so I can pull the hotend off and change the nozzle, but honestly I don’t think I have printed nearly enough to justify the nozzle having gone bad yet. I will then let it resume and see what happens with a brand new nozzle. But this is driving me crazy.

I am using Bambu Studio, all settings default from the people who make these models and such.

I’m not sure what other information I can provide.

Edit: Let me add that when it’s printing, and not clogging with a filament change, it prints great. It’s just when it changes filament during a multicolor print.

Edit 2: I thoroughly cleaned the nozzle, same thing on the very first layer. I replaced the nozzle with the spare that was sent with my printer, clogged on the second layer.

Edit 3: Replaced the PTFE tube inside the printer, it finished the rest of the print I had been working on. About 3 hours of printing, no problems. Started a new print this morning, clogged on the second layer during filament change.

1 Like
2

Hi, I had this same problem. I noticed that it did not happen with Hatchbox PLA. I am curious to hear what others have to say.

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Well my issue is happening not so randomly with several different brands, including Bambu, which is the primary brand I have. I would think their own filament should have the least issues.

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It may be nothing, but I would check the filament cutting blade. There’s a spare in the box the printer shipped with so it should be a quick and easy fix if it looks beat up or damaged. Equally, you might get a confirmation of a problem if you pull one of the other filaments out of the AMS and check the end. It should be very uniformly cut and clean.

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I actually looked at the blade when I removed the extruder yesterday and it looked fine, cuts look clean.

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I guess you can’t edit the message after a day or two. So I printed the second print. After all of this it did print significantly better, but it still had multiple clogs on color changes in a 12 hour print, it had to be told to try again on clogs probably 10 or so times in several hundred layers. So yeah, changing the tube helped, but it’s still having a problem.