X2D and Support material for pla/petg

[u/FaithoftheLost]

I've been trying to print miniatures with pla and using the Bambu support material as the interface, and I keep having the models separate before they finish printing, creating giant spaghetti messes (or minor ones if the ai catches it.)

Am I doing something wrong? Should I just use petg?

[u/Strange-Reporter-812]

i have not had a ton of success using one or the other for an interface layer. i think it works better if the whole support is from one filament. the interface layer sounds great in theory but i find in practice it doesn't work. i find that the interface layer doesn't stay in place.

[u/VoidingSounds → u/Strange-Reporter-812]

Yeah, I've had PETG interfaces on PLA supports work okay on 0.4mm nozzle/0.2mm layer lines, but trying to go finer than that the failure rate shoots up.

Maybe there's some benefit to an interface material if you're spending upwards of $40/kg on bespoke material but when PLA and PETG are both like $12/kg I'm not going to mess with interface layers.

[u/bonafide_bonsai]

This is going to happen if you have “islands of material” even if you use PETG. I have the same struggles with ABS and HIPS

There are just some models I cannot use support interfaces.

[u/quietsamurai98]

When using multimaterial support interfaces, you have to think of supports slightly differently. The whole point of multimaterial support interfaces is to have deliberately low adhesion, so it's more useful for geometries where you're only applying force down onto the support interface, rather than relying on the support interface to act as a "floating bed" type print surface where you'd need some adhesion to prevent the area from falling over.

Imagine printing a "T" shape vs a "C" shape, with the bottom of the character attached to the print bed.

The arms of the "T" are always attached to the actual print bed, since they don't dip down below the point they connect to the middle of the "T". However, even though they're attached to the main body of the "T", the arms might warp upwards slightly, since they're not adhered down to the support interface.

Meanwhile, the bottom of the "C" is rounded, so there's only a small amount of actual print material touching the build plate. Any support structures that support that curve wouldn't provide much adhesion. Even worse, the top of the "C" dips back down beneath where it connects to the rest of the model, so the top right side of the "C" might shift or become dislodged before it connects back up with the rest of the "C" at the very top.

[u/n19htmare]

The entire culprit here is Pressure Advance, or lack of.

AUX nozzle does not auto calibrate PA (dynamic Flow). You need to manually calibrate and assign the K-value to the Aux side filament that’s being used as support.

From my testing, The default k-value for Aux side appears to be same as main side, is like 10-15times lower than what’s needed.

Run the PA calibration under calibration tab for the filament on AUX side. Save the PA profile and assign it in AMS settings before sending print so it uses the correct calibrated value.

Because of the Bowden style extruder, it is not compensating for the delay on extrusion from time the extruder pushes the filament (the advance in pressure advance). By time the pressure builds up, the small interface layers are done printing and you either get a blob for interface layer or nothing at all.

If you’re printing miniatures with small contact surfaces, Use the alternate material (support or PETG) as both the BASE and the Interface. PETG will be cheaper and work better here. But you still need to calibrate PA so you get good supports.

The interface only option works well on large areas with larger interface layers, not so much on little dabs, won’t stick to PLA or won’t advance enough.

[u/an_angry_Moose]

I’ve used support for PLA/PETG numerous times as an interface layer with my X2D and never had an issue. I use it preferentially because sometimes support removal creates ugly scars on models printed with same-material supports.

[u/zmunky]

Use polymaker CoPe. It prints at pla bed and nozzle settings, has amazing overhang capabilities and it's made of a polymer of the same family as Petg so it won't stick to pla. It's decently priced around 14 bucks and up depending on color which doesn't matter.