2.4 Support material, and the X2D's second nozzle
Module 2 · Lesson 4 of 10 · about 7 min
The problem: supports printed in the same material as your model stick to it, and you spend twenty minutes with pliers making scars.
How breakaway support works. Breakaway support filament is designed so that the layer where the support meets your model, the support interface, bonds only weakly. The support peels off cleanly and leaves a smooth surface behind. The filament itself is not fragile. You handle it and store it like any other filament.
Soluble supports, the other common method, are not allowed on our printers (2.1 What you may print: the allow-list).
A test part held in two hands, with its support pulled away from an overhang: the white support interface comes off as one clean layer, with the grey support base behind it
Which support filament to use
For PLA, use Bambu Support for PLA. It is the recommended choice. It costs about half as much as Bambu's combined Support for PLA/PETG, and it is less likely to stick too hard on a SuperTack plate. On the upper row it is the only support material allowed, and it is fine on SuperTack plates. The member shop sells it.
For PETG, use Bambu Support for PLA/PETG, which is made for it. It works with PLA too, but for PLA, Support for PLA is the better choice. It is not allowed on the upper row, and Bambu warns that it can damage SuperTack plates.
For ABS or ASA, use Bambu Support for ABS.
For any other material on that printer's list, use a breakaway support filament that its maker states is compatible with that material. It doesn't have to be the same brand as your model filament.
Other brands' breakaway support is allowed on the lower row and the H2S. Bambu's own support filaments are tested on these printers, and others are not. So if you use another brand:
Set the material type by hand every time you load it. It has no RFID tag.
Dry it at its maker's temperature, not a figure from Bambu's table (2.7 Drying filament, and the two dryers).
Watch the first few support layers. If it bends, grinds or feeds unevenly, it may not suit the AMS feed path. Stop the print and ask in Slack.
A free trick: PLA and PETG don't stick to each other
Because they don't bond, you can print a PETG model with PLA supports, or a PLA model with PETG supports, and the supports come off cleanly.
Two limits.
The room: you need PETG, so this only works on a lower-row X2D or an H2S, never the upper row.
The filaments: Bambu says it works with Bambu PLA Basic together with Bambu PETG HF or PETG Basic. It does not work with PLA Matte, PLA Silk, PLA-CF, PETG Translucent, PETG-CF or unknown filament. With other combinations, expect the supports to stick.
Recommended: use support material only for the interface
A supported overhang: the support body underneath, and the thin support interface where it touches the model
We recommend putting support material only on the support interface, the thin layer that actually touches the model, and printing the rest of the support in your model filament. Only the interface needs to come off cleanly. Printing the rest in your model filament means:
Far fewer filament changes, so much less purge waste and a much shorter print.
Much less of the expensive support filament used up.
The same clean surface on your model.
Bambu's own test makes the point. For a PETG model with supports printed entirely in PLA, the print took 5 h 3 min. With a PETG support base and only a PLA interface, it took 1 h 20 min less and used about half the prime tower, with the same finish. (These are Bambu's figures, quoted as an example.)
Bambu's test: the same PETG dinosaur with PETG supports (2 h 15 min), with supports entirely in PLA (5 h 3 min), and with a PETG base and a PLA interface (3 h 43 min)
Setting it up in Bambu Studio
Bambu Studio's support settings for an X2D, marked with steps 2, 4 and 5: Enable support, the base and interface filaments, Top Z distance and the interface pattern
Load your filaments and sync Bambu Studio with the printer.
Support tab → Enable support.
Choose the support type that suits the shape of your model. If you are unsure, keep the default.
Set support/raft base to your model filament and support/raft interface to the support filament.
Set Top Z distance = 0 mm and the interface pattern to Rectilinear Interlaced. That gives the model a solid surface to print on that still comes away cleanly.
With support painting, you can paint support only where it is needed instead of letting the slicer support everything. Overhangs beyond about 45–50° from vertical usually need support (1.1 How a 3D printer works, and the words for it).
Which nozzle does what on an X2D
An X2D in the rack, with its four-spool AMS 2 Pro on top and its one-spool AMS HT to the right
The usual setup: your model in the AMS 2 Pro (left nozzle), support material in the AMS HT (right nozzle). That is what Bambu designed the X2D for, and the setup this course teaches:
The left nozzle gives the best control, so it prints the surfaces you will actually see.
The right nozzle is slightly less precise, which doesn't matter for support that you snap off.
The model and the support each have their own nozzle, so switching between them doesn't need a full purge.
Things to know about the right nozzle:
The AMS HT holds one spool, so you can use only one support material per print.
The right nozzle is slower. Its Bowden drive pushes the filament through a long tube, which gives less precise control than the left nozzle's direct drive, so it cannot print as fast. The installed profiles are already set for that, so don't increase its speed. For thin support interfaces the difference hardly matters. If you use the right nozzle for a larger share of the print, such as a second material or colour, it can make the print noticeably longer.
The print volume is slightly smaller when the right nozzle is used (see below). If your part is close to the size limit, check it in the slicer.
Its print quality is a little lower, because it moves up and down often and is fed by a Bowden drive, through a long tube. If surface finish matters, use the left nozzle.
Print volume on an X2D
Manufacturer figures, width × depth × height:
Which nozzles the print uses | Print volume |
|---|---|
Left nozzle only | 256 × 256 × 260 mm |
Right nozzle only | 235.5 × 256 × 256 mm |
Both nozzles, such as model plus support | 235.5 × 256 × 256 mm |
So as soon as a print uses the right nozzle at all, you lose a little width and height.
Other filaments in the AMS HT
Anything other than one of Bambu's own support filaments in the AMS HT, including another brand's support? Check Bambu's list first. Bambu grades every filament for each X2D nozzle in its X2D Filament Compatibility Guide, and the grades change as Bambu tests more materials and updates its firmware and profiles. Bambu's support materials that are allowed here (Support for PLA, Support for PLA/PETG and Support for ABS) are all rated good for the right nozzle. For anything else, look it up before you load it. Many filaments work on the right nozzle but fail more often there than on the left.
⛔ Hard rule. Never load a filament in the AMS HT that Bambu's X2D Filament Compatibility Guide rates highly not recommended or unavailable for the auxiliary (right) nozzle. The ratings change over time, so check the guide rather than relying on memory.
Support material on an H2S
On an H2S, support material goes in the same AMS 2 Pro and shares the single nozzle. That is allowed, but every switch between model and support is a full filament change with purging. The print takes longer and wastes more, so keeping support material to the interface matters even more there.
Image sources: support being peeled off, Support for PLA, Bambu Lab product photo; support diagram and support test, from Bambu Lab's Printing guide for using PLA and PETG for support.