Hello fellow Bambu Lab owners. Do you hate all that waste that the AMS units generates? Me too. That's why I made this guide how to reduce / tune / calibrate / optimize the purge waste.

If you find this guide helpful, I'd be glad if you post a make, like this project and/or add it into your collection. If this project helped you save tons of filament, any donation via Paypal is greatly appreciated.

Version history:

V2.0 (5.2.2023)

Initial public release.

V2.1 (5.2.2023)

Previous version used 2 walls and printed the inner wall first so the color bleed could have been hidden. I changed walls count to 1, removed infill and changed object shape to cylinder (prints a little bit faster). I had to make the size difference only 0.4mm so it is printable (due to no infill and only 1 wall).

I also removed top layers and moved seam to the back.

V2.2 (6.2.2023)

Changelog:

• Sets Quality > Order of inner wall / outer wall / infill to outer/inner/infill. It's for those, that want to set wall count to 2.

How to Tune

Remember! Each material type or even the same material, the same color but from a different manufacturer can behave differently. It's a good idea to use this project if you use the same filaments all the time. If you like to experiment with different manufacturers, be on a safe side and don't ruin your large prints.

Step 1 - Download and open

Download the ams-purge-waste-calibration.up-to-8-colors.v2.2.3mf file and open it.

Step 2 - Set a number of colors

Currently this project supports only 8 colors. The 16 colors version will be added once I get through the beta testing with you guys.

It depends on how many AMS units you have. If you have less than 8 colors, go to Process > Objects and delete all groups that have higher color number than you want.

For example: You have 4 colors, delete groups 8th color, 7th color, 6th color & 5th color.

Step 3 - Arrange all objects

If you deleted any groups, rearrange objects.

Step 4 - Update colors & filament presets

Change the colors (or sync with AMS) and set correct filament presets!

Step 5 - Set flushing volumes & flushing multiplier

Now click on Filament > Flushing Volumes.

Then click on Auto-Calc button and set the initial Flushing Multiplier. I started with 0.7. Don't forget to make a note of the value set.

Step 6 - Update process preset & printer preset

If you don't use the default presets (or you have X1 / X1 Carbon), set correct Printer Preset.

If you don't use the default Process Preset, set all settings (or transfer the settings) as seen on the picture below. Otherwise the calibration won't work as intended with this project.

Step 7 - Inspect and tune the multiplier

Once the print is finished, inspect the models, especially color transitions and look for color bleed. If there is color bleed, you have to up the value. If color transitions are sharp. Move to Step 8.

What is color bleed?

Color bleed is a situation where the flushing volume was not enough to fully transition from old color to new color. A layer (or part of a layer) is printed with a mix of old color and new color.

Step 8 - If everything is fine

If everything is fine, you can lower the Flushing Multiplier and repeat the test. How much lower you can set it? It helps to inspect the poop and look how much filament there is between the transitions to get a better idea.

If you have any suggestions, leave them in the comment section. Happy calibrating!!

Appendix: Are there all color combinations?

Here is a “Math Proof” for 4 colors.

What we are looking for is variations (nowadays called k-permutations of n), where n = 4 and k = 2.

The formula is n! / (n - k)!. If we plug those variables in, we get 4! / (4 - 2)! = 4! / 2! = 4 * 3 = 12. So there are 12 different color transitions.

Group called 4th color has color transition sequence 4342414. From this sequence, we get these transitions {43, 34, 42, 24, 41, 14}.

From group called 3rd color we get 32313 → {32, 23, 31, 13}.

From group called 2nd color we get 212 → {21, 12}.

If we sum them up, we get 12 transitions, each unique.