H2C + Filament Track Switch + 1 AMS & fixed slot-to-hotend - avoid purging?

Bambu Lab H2 Series Bambu Lab H2C
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Hi everyone,

I’m planning to buy a H2C with a single AMS 2 Pro and I’m planning to install the Filament Track Switch. My use case is small-batch production of 2-3 color logos/lettering.

My question is about a specific configuration, not the general “can 1 AMS feed both nozzles” case (which I’ve seen discussed already):

If I permanently dedicate AMS slots to specific hotends — e.g. always route Slot 1 → left nozzle, and always route Slot 2, 3, 4 → three specific, separate right-side Vortek hotends (never mixing which slot feeds which hotend) — would this avoid the purge/prime tower entirely, since each hotend would always retain the same single material, the same way it works with multiple AMS units?

In other words: is the “zero purge” benefit tied to each hotend staying dedicated to one material (regardless of how many AMS units feed it), or does using the Filament Track Switch with only one AMS force a purge cycle even with this kind of fixed, permanent mapping?

Does Bambu Studio / the firmware actually support locking a specific AMS slot to a specific right-side hotend permanently (not just “left vs. right” as a general side), or does it only support left/right routing without slot-level pinning?

Any insight from someone who’s tested this, or from the Bambu team, would be much appreciated!

THX,
Sven

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I can’t answer the filament track switch questions, since I don’t have one, but I can say that no matter what configuration you have, if you are switching between filaments or nozzles, there will always be a need to “prime” the nozzle, which necessitates the prime tower. You can disable the prime tower for prints, but that potentially introduces quality issues. So if you are printing with multiple filaments in one print, you can expect some amount of filament wastage.

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You can assign slot 1 to left nozzle and slot 2,3,4 to right nozzle with a track switch.

But, the AMS only has one output PTFE tube, it can only supply filament to one nozzle at a time.
Therefore, every time the printer switch between nozzles, the filament must be cut and retracted to make space for the next filament. So it will take a lot longer to print multi colour compared to either 1 AMS on each nozzle or AMS on right nozzle and external spool on left.

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THX for the replies.

yes and to have a faster and constant print - separate AMS or Spool only for left will be the better idea :wink:

So that means, if left nozzle is always slot 1 and 3 right nozzles using constant always asssigned their slots - the cutting topic I understand but why flusching?

Ah because maybe of the small rest between cutting blade and nozzle or is that a fallacy?

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There is no flushing when changing colours or nozzles on H2C. The little “poop” is only generated once at the start of loading each nozzle.

There will always be a prime tower (some people call it a purge tower) when switching colours or nozzles, regardless if filament needs to be cut or not. This is required to balance the pressure in the nozzle before printing (to “prime” the nozzle). It’s for improving print quality.

You can switch off the prime tower in the slicer, but it’s not recommended.

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Perfect — now I understand the process, especially with the H2C (of course, the same principle applies to other printers as well).
With the P2S, I’ve often skipped the Prime Tower, but then realized that it would have made sense to use it — switching between red and white :zany_face: