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Choosing the left or right nozzle on a Bambu Lab H2D or H2C

Choosing the left or right nozzle on a Bambu Lab H2D or H2C


On a two-nozzle Bambu Lab printer like the H2D or H2C, each filament prints from one specific nozzle, and that choice is made when the file is sliced, not when the print starts. This guide shows how to pick the left or right nozzle in the Cloud Slicer, how the nozzle shows up when you map AMS slots before a print, and what to do when SimplyPrint "won't let you" use the nozzle your AMS is connected to.


The two nozzles sit side by side at a fixed distance, so a file sliced for the left nozzle can't simply be printed with the right one. If you can only pick spools from one nozzle when starting a print, the file was sliced for that nozzle. Re-slice it with the filament on the other nozzle.


In this guide


Pick the nozzle in the Cloud Slicer

  1. Open the file in the Cloud Slicer and select your H2D or H2C as the printer. Use the Bambu Studio or OrcaSlicer engine; the other engines slice for one nozzle only.
    • Check: the Filaments section in the sidebar shows two columns, Left nozzle and Right nozzle.
  3. Next to the Filaments heading, click the nozzle assignment icon and choose Manual ("Assign filaments to nozzles yourself"). Manual is the default.
    • Why: in Filament-saving mode the slicer engine picks the nozzle for each filament to waste as little as possible, and the two columns are hidden.
  5. Add each filament to the nozzle it should print from: click + at the top of the Left nozzle or Right nozzle column. To move a filament you already added, drag its card into the other column.
    • Check: each filament card sits in the column of the nozzle whose AMS (or external spool) holds that filament.
  7. Assign the filaments to your objects as usual, then slice.
    • Check: hover the Slice button. The Nozzle assignment card says "Filaments are sliced with the nozzles you've assigned them to."
  9. Save or send the sliced file to the printer or queue.


Map AMS slots when you start the print

When you start a multi-color print, SimplyPrint shows the AMS mapping step. On a two-nozzle printer the file's filaments are grouped by nozzle: Nozzle 1 is the left nozzle and Nozzle 2 is the right nozzle.


  1. Click each filament in the mapping step.
    • Check: the list only offers slots that feed the nozzle the file was sliced for. Slots on the other nozzle are not listed.
  3. Pick the slot holding that filament. SimplyPrint pre-selects the best match it finds.
  4. When every filament is mapped, the "Must select/map materials" note disappears and you can start the print.


The external spool of a nozzle is used only when it's loaded and that nozzle prints a single color in this file. With several colors on the same nozzle, the print needs the AMS slots.


Why the start dialog only shows one nozzle

If the queue or the start checks say "It's loaded on nozzle 1, but this file prints it with nozzle 2" (or the other way round), the filament is loaded on the other nozzle than the one the file was sliced for. Two ways to fix it:


  1. Re-slice the file with that filament in the other nozzle's column (see Pick the nozzle in the Cloud Slicer).
    • Check: start the print again. The filament can now be mapped to the slot you wanted.
  3. Or move the spool to an AMS (or the external spool) on the nozzle the file was sliced for, then refresh the spools in the mapping step.
    • Check: the slot shows the spool on the expected nozzle.


If the message is "It's on the external spool, which a print with several colors on this nozzle can't use", load that filament in an AMS slot on the same nozzle instead.


Files sliced in Bambu Studio or OrcaSlicer

The same rule applies to files you slice on your computer: the nozzle is set per filament in that slicer before you slice. Upload the sliced file to SimplyPrint, and the mapping step offers slots on the nozzle each filament was sliced for.


Fixed issues: custom profiles and the missing nozzle picker

Two bugs made it look like the nozzle couldn't be chosen. Both are fixed; reload the Cloud Slicer page to get the fix.


  • Saved custom machine profiles became single-nozzle (fixed 22 September 2026). Saving or duplicating an H2D machine profile stored one nozzle instead of two, so every filament landed on one nozzle. Profiles saved before the fix were not repaired, and saving such a profile again keeps it single-nozzle. If a custom profile shows only one nozzle column, select the printer's system profile, check that both columns show, make your changes and save them as a new custom profile.
  • No left and right columns without the printer on your account (fixed 12 October 2026). Picking an H2D or H2C model from the catalog, instead of a printer added to your account, showed a single nozzle.


H2C and Filament Track Switch: current limits

  • H2C nozzle rack: not supported yet. The Cloud Slicer slices the H2C as two nozzles, left and right, and SimplyPrint doesn't tell the printer which rack nozzle to use when it starts a print, so print files that only use the left and right nozzles. In the printer's settings you can still set the size and type of each nozzle on the H2C.
  • Filament Track Switch: SimplyPrint doesn't fully support Bambu Lab's Filament Track Switch yet. With a track switch fitted, SimplyPrint can assign every slot to one nozzle, and slots you move by hand can jump back after a print or a sync. There's no setting to work around this; printing without the track switch avoids it.


You can follow H2C progress on the suggestion board.


Updated on: 27/10/2026

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