Thoughts and ideas on the dual nozzle system

I’ve already read in a few other threads about some users’ frustration with the built-in dual nozzle system featuring a single-sided Bowden extruder.

On the one hand, I understand their frustration;
on the other hand, I understand why Bambu chose this approach.

If it were up to me, I would have taken a different approach.

My idea would have been this:
when switching nozzles, simply switch the extruder’s drive mechanically to the second filament and reverse the stepper’s rotation direction. It would essentially be a dual-nozzle-single-stepper drive. And it could have been implemented using simple mechanics, since the stepper drive only needs to be moved a few millimeters. Or you could do it using the counter-rotating gear, which would essentially be decoupled, but this would likely lead to wear.

But if, as a manufacturer, I already have a nozzle lift/lower mechanism, it should be easy to implement a stepper tilt function on it as well to drive the filament being fed, and then either reverse the stepper via software or even simply reverse the motor’s polarity with a switch.

The question is, did Bambu have something like this in mind? Have you explored and tested other approaches? Was and is this there only design for the X2C?

This isn’t meant to be a rant; I’m just trying to explore a few other feasible ideas.
So let’s hear your thoughts.

As I just discovered on Bambu’s website, they use a similar technique on the H2D, but with an additional stepper motor that positions the side. To press the filament against the stepper, my idea would be to instead press the stepper against the correct filament, using the nozzle’s up/down function purely mechanically.

111_(2)

Source: HMS_07FE-8100-0002-0001: The extruder switching action is abnormal. Please check whether there is something stuck in the toolhead. | Bambu Lab Wiki

1 Like

Congratulations, you have invented the H2D.

There’s a reason why they didn’t just do that here - the H2D/C extruder head is massive, heavy, and necessitates a much beefier drivetrain that would be unsuited to the compact package of the X/P series.

1 Like