I own other dual nozzle printers and have learned that using cleaning filament is essential. Its broad temperature range helps protect the nozzle from damage when mixing different filament types, including TPU.
When loading new filament with the AMS, some old filament remains in the nozzle until the printer purges it at the beginning of the next print. If your last filament was PLA in the right nozzle and you’re now printing with a 320°C filament in the left nozzle, the right nozzle might not react well next time you go to use it.
To simplify the process, I first use the AMS to load cleaning filament, then manually set the nozzle temperature and purge it until all traces of the previous filament are cleared. For convenience, I keep the cleaning filament on a dedicated spool.
I highly doubt if a cleaning filament is really necessary. It is only needed for printers that cannot remember the last filament in nozzle. Or if you’re replacing a nozzle with PPS/PPA inside.
If your last filament was PLA in the right nozzle and you’re now printing with a 320°C filament in the left nozzle, the right nozzle might not react well next time you go to use it.
Are you sure this is the behavior? AFAIK the H2D remembers the last loaded filament for each nozzle. The problem should only happen with switching from higher temp to lower temp materials.
If I use same type of filament often, it’s not a problem. However, human mistakes are unavoidable, and that’s when you might find yourself dealing with a jammed $20 or $50 nozzle, or shredded TPU inside the extruder, and unexpected downtime.
Whether it happens depends on the level of risk you’re willing to take. Personally, I don’t like dealing with nozzle replacements or losing print time, so I play it safe.
If you don’t have cleaning filament, try testing with some clear filament you might be surprised by how much old residue remains in the H2D nozzle.
Cheapest way to get some cleaning/flushing filament is to buy some “Ziro” brand filament, they all come with a bag of 5M cleaning filament. Ziro is pretty good filament and has some colors no one else has like translucent fluorescent PLA etc.
Also as other have mentioned H2D remembers the last filament used and adjust the flushing temp. After I learned it does that I only use the cleaning fialment before I print TPU from external spool. Just pop out the PTFE tube from hot end and manually extrude a strand.
Yes I also switch nozzle sizes. Maybe I’m a bit old fashioned but I learned my lesson back in 2018 using dual nozzles on Raise3d printers. It’s just now part of my 3d printer routine.
Just be careful - I also use cleaning filament to purge any leftover material whenever I remove and store the nozzles.
Thats not ideal as it would require you to rerun high-precision nozzle offset calibration each time you swap hot ends for best print accuracy. I print a lot of TPU and that would be very tedious, flushing the hot end its much faster a few minutes. If you dont do the high-precision calibration than it does not matter.
Is that really necessary though? I’ve swapped hotends multiple times now and never did that calibration again. I can not see any issues when using both nozzles in the same print.
Have you ever tried starting a PLA print after previously printing with PPA-CF? It doesn’t work out too well. PPA-CF will not completely purge out at 250°c and heating pla up to 300°c+ is kind of idiotic.
Cleaning filament can handle the entire temp range and the machine makes cold pulls effortless. This isn’t about whether it can be done a different way, this is about convenience.
It’s not about assuming the nozzle is damaged it’s more about maintaining optimal performance, especially when you’re switching between materials like TPU and others. While purging at the start of a print can help, over time, the buildup of residues can still affect the print quality, with different filament types.
Bambu might not “require” a cleaning filament yet, but it’s a helpful tool for ensuring consistent results, especially for users who switch filaments often or want to avoid clogs and under extrusion. Some users don’t need it, but others find it useful as an extra layer of precaution for longevity and print quality.
Just sharing another perspective everyone has their own workflow that works for them!
Yup, when I flush with clear cleaning filament after PPA or PPS you can see the black pieces of filament and CF for a long while. It stays like that for much longer than the standard auto flush volume. PPS also has a tendency of crystallizing in the hot end when cooled so not a good idea to leave it in there.
I dont flush often just after PPA and PPS and sometimes before feeding TPU if I previously printed a high temp material like nylon from that hot end.
As other have mentioned it stay solid at high temps and does not liquify like PLA, and can be extruded at 320c or 150c. You dont have to do it, but its useful in those situations. If you dont print high temp materials or TPU then its not needed.
Also as I mention I dont buy it, it comes free with Ziro filament that I already use.
economically