Hi,
I am printing parts with only one filament, located in my AMS pro2. Sometimes the printer is cutting and reloading the filament, but a cannot see any reason for that, because the spool is running freely. Its not that big issue, but it is time consuming and filament waste. Sometimes there also is coming a “AMS motor overIoad” error, which must be confirmed manually - which is useless, because everything is working fine after confirming. I would love to find out what to do to avoid this behaviour. Any idea? And how can i switch off this annoying warning?
I am working on resolving this same issue. Shorten your PTFE tubes as much as possible. Install printable bend guides, rerun the AMS setup. These three things helped some.
I have found that on slot 3, in the back there are two spool guides, the right guide was creating a lot of dust, grinding away at the spool. I cut the guide out. Next point of contact when the AMS reports motor overload, appears to be the spool rubbing the side of the slot. I have mounted a bearing so the spool rubs the bearing. Big reduction in rolling friction after those two changes.
Bearing against the side of the spool is still being developed, I have tested it, hope to finish the mod soon.
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Thanks, MiamiJerry. I am not sure if the reloading is triggered by a resistance inside the PTFE tube because of the following observations:
The filament mostly is reloaded without any warning or error. Sometimes there comes this “overload” message - in this case you are obviously right that its the high resistance. But what, if the spool turns really freely?
That’s a very characteristic behavior of ptfe tubes, usual once it’s through, the friction suddenly reduces a lot. It’s caused by pressure points inside the tube, so it would be pretty “ghostly” to diagnose.
I’m sorry, but i don’t understand what you mean: Of course there can me a lot of resistant during the initial feeding of a filament, but during printing i observed a very freely gliding and rotating of the spools. I have a complete standard setup and standard materials, so i do’nt see a lot of space for optimisation (besides the things you mentioned, but i don’t like to start changing the hardware of my AMS and printer at that point of time. Let me tell you why: I worked with a horrible Raise 3D printer for a long time and installed every mod that you can think about (thik al-plate, water cooling for hotend and motors,…). After being not really satisfied i switched to QIDI. Lots of errors and interrrupted prints there. Now i decided to give Bambulab a try, because lots of people told me, its “Like Apple”, a closed, but therefore working system. Now i must realize that its not as plug and play like people told me. That said: Before i start tweaking again i want to be sure that i didn’t miss any more simple solutions. Maybe i will take a support ticket and see what Bambulab says. Did you do that?
I don’t understand your problem because you say sometimes the printer is cutting and reloading the filament and you can’t see any reason for it. Do you mean that the printer will be printing then suddenly out of nowhere it just goes and cuts the filament? Then it reloads it?
Watch the buffer, is it getting stuck compressing? Have you checked that the buffers are working properly and there is no resistance there? Make sure to take the tubes off and check for broken piece of filament.
The buffer is going left and right, using most of its range. First of all let me ask: Do you know which sensors or cirumstances are causing the printer to reload the filament? Is it the sensor at the buffer? Or is it e.g when the printer detects too less flow inside the extruder? I am quite new to the bambu world and don’t know exactly how these machines are „thinking“…
It’s when the printer detects that it’s using too much force to extrude. Either from the extruder or from the extruder motor on AMS.
In my opinion it does not take much added friction for the printer to warn motor overload. I only note little things like the spool guide rubbing. After I cut the spool guide as show above, I have complete two 5 hour prints, whereas before it warned motor overload 3 to 5 times a 4 hour print.
Spool side roller bearing mod
TBH it’s more of a spool compatibility issue. Which isn’t new ever since AMS become a thing.
faulty buffer? If I print in the front left corner of the bed I will get unloads constantly, says the spool is stuck but it isnt. you can hear the buffer click when it breaks free, there isnt enough PTFE tube to reach that front corner but it already rubs against the roof of the printer so adding a longer tube is not an option as its already showing signs of wear. bambu claimed the buffer was fine but you can see it getting stuck while printing in the front left corner
I have a similar problem. At first, while printing in the middle and on the left side at the front, the printing suddenly stopped and the filament was winding and unwinding back and forth. This caused printing errors. I cut half of the PTFE tube, the one between the AMS and the printer. This improved things so that it was printing continuously without interruptions, but when the print head was in the same position, the buffer spring would snap and make noise. Something is still not right. I think I probably need to slightly extend the PTFE tube. The one inside
Yes, buffer bangin’ is caused by internal PTFE too short