Reducing waste from Bambu Lab AMS (lite) prints

Bambu Lab 3d printers produce really clean multi-material results. However, due to a filament cutting system that prioritises reliability, there can be an excessive amount of filament and time wasted. In this video, I explore some options for clawing some efficiency back. The gains aren’t huge, but are still worthwhile.

Thanks to my patron David who inspired this video during a great discussion.

0:00 Introduction

0:50 How the Bambu Lab filament change system works

2:43 Test multi-colour print

3:20 Single colour vs multi-colour

4:40 Purge into infill and/or support

6:08 Flushing volumes

8:56 Potential g-code tweaks

9:57 Printing multiples for efficiency

10:41 Conclusion

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[AndySmallfry]

Theres a model on printables called "Bambulab Profile for up to 60% purge reduction" and it does exactly that. Pretty much it moves the filament up close to the cold end before cutting it. This reduces the physical amount the needs to be extruded.

[sambarney]

Your channel and CNC Kitchen are probably the best resources for 3D printing.

[boots]

YouTube videos that save me money are my favorite YouTube videos. Very well earned "Like".

[sonofbrun]

Layer height also makes a big difference. Fewer layers means fewer filament changes.

[hagus]

You can also purge into an object. So if you have a tool or something where you don’t care about color banding, that can be an option instead of duplicate models

[woodwaker]

I like the way you visually showed the results in the bins. I like the AMS, but I try to print with less than 20 color changes and fill the build plate with as many copies as possible. I think your results could be even better if you ran some tests to get the color swap amounts down to the bare minimum.

[gibsonsimpson]

Excellent analysis. Glad to see if you print multiple models, the waste doesn't increase and the time increased slightly. Great info to know!

[roysigurdkarlsbakk]

Just one thing… If you use flushing volumes / autocalc, IMHO that works well, also with at factor as low as 0, 3, but I guess that depends on the model. But, if you later change filaments, which you generally do a lot with a 3d printer and forget to go by flushing volumes to update the calculation, note that that will not update automatically and you'll end up with a flushing table written for a completely other world than the one you're in and if you, perchance, start a print at night and go to bed and wake up the next morning to find your flashy new print, it'll look like rubbish. Beleive me on this ;)

[ggaub]

We MMU2 users have been doing these things for ages, of course. One of my go-to methods is sacrificial waste/wipe/purge objects that can be scaled to the size of the main printed object. The four stones from The Fifth Element are my favorite, and I set the whole object as purge/wipe. These can then be quickly sprayed with stone color paint, or even left as-is. I find that people like the crazy colored stones as much as the painted ones. With purge to infill/object, and printing multiples of the multicolor model, per-print waste is greatly reduced. My new XL is putting that to shame, though. It does need some better tuning for print quality, but the only waste is the priming tower, which some people have even disabled with success.

[CrudelyMade]

Filament could be saved if they had a slicer feature that could do variable infill or use the waste material on a second model where colors don't matter. But a model with 10% infill has plenty of room to use up some of that otherwise wasted filament.

[Exodus]

I think one of the most important tuning areas for multi material solutions like the AMS is print orientation. Instead of requiring material changes for every single layer, orienting the model vertically would reduce them significantly. Of course this is not a viable solution for every application, but nevertheless very important to keep in mind while doing multi material prints.

[umakedprinting]

I use S3D for my Bambus, also for AMS prints. I’ve added a pre-toolchange gcode that makes the filament retract to about 8-5 millimeters below the cutting section before the switching filament starts. There is way less filament to purge, and has been reliable since.

[petersvideofile]

IDEA/QUESTION: Based on the extruded junk at 8:32 and also by the graphic shown at 1:27 is it fair to say that more material could and should be pushed out of the extruder and perhaps it should be cut BEFORE the transition in color takes place. Like couldn't one calculate the amount of material that was between the cutter and the nozzle tip then do a volumetric calculation to prematurely cut and exchange the filament? This almost seems to simple, like it should be being done already. The graphic shown at 1:27 doesn't indicate if it does the cut before it wants to start printing in another color or not, but I was left with the impression it is cutting and exchange at the instant it wants a color change. If the flow of filament is pretty laminar and doesn't mix too much (hard to tell from the 8:32 poop), then perhaps this technique of prematurely cutting and swapping would save even more filament (if it's not already being done). Just and idea, which seems really simple so I kind of have to assume it's already being done and I'm just never heard anyone say it.

[Prof.Polymath]

I don’t have a bamboo labs yet but if I did; this would be one of the most useful videos I’d ever seen. Great video, great process, and really well presented. Thank you for sharing. 👏🏼👏🏼👏🏼

[wktodd]

If it could cut before the colour change, using the stub of first colour until it is almost changing, then a small purge to the second colour, before returning to print the second colour.

[astropgn]

Imagine if the slicer had a "low priority print" that only prints with the flushes? It would print the main object with the correct filament, but when it is transition, instead of throwing away the filament it prints another object, something that you defined as low priority in terms of color. That second object will have an arbitrary color, but at least you wouldn't waste material.

[spencerdiniz]

Another factor that wasn’t mentioned, but I imagine would also be able to reduce waste is orienting the part to minimize filament changes. For example, the marlin model, if printed vertically, I think would require less filament changes… with the tradeoff that it would require supports.

[ChrisUG]

Orientation can also massively affect tool changes

[Cpgeekorg]

I have a p1s+ams on order that should be here next week and this experiment will be EXTREMELY helpful to guide my workflows for multicolor printing. thank you!

[mmTech]

For that particular model, I'd be curious to see you shift it to a vertical orientation with supports and see how that impacts the volumes. By having the color changes oriented to the direction the model is sliced, I'd imagine significantly fewer material changes and purges. Obviously, you would now have material in supports, but it would still be interesting to see the impact.