Prime tower minimum flushing

[GalaxyRiver]

Using A1 with two filament colors. Bambu Studio. I would be grateful if anybody can help ease my confusion…

1. Under Preferences there are settings for auto-calculate flushing volumes. How do these settings affect/interact with the prepare/preview (left hand side - filament) “Flushing volumes” settings? Does the “auto-calculate” refer to auto-calculating mid-print or what? Is it just referring to whether or not you want the values in the flushing volumes box to automatically change when the filaments/color spools are changed? (Why would the calculation be different if you changed a filament but did not change color?) I am a little confused here.

2. Is there a good reason the prime tower is so far away from the print and unmovable? Would it not be sensible to have it close to the print to reduce travel distance between tower and print?

3. Is “purge” and “flush” the same thing? If so, why are both terms used within the software? It seems we also have “wipe”. Is that different?

4. This is my main question. With prime tower turned off, the flushing volumes can be set down to zero. With the prime tower on, regardless of the tower width and volume settings, there appears to be a significant minimum flushing volume (listed under “Flushed”, not “Tower” in the Color Scheme box - Filament) that cannot be avoided (unless you “flush into this object”). Regardless of reasons why you might not want to, why can the flushing volumes not be set down to zero with a prime tower?

5. Why does the software insist on a prime tower if we want to flush into support or infill (again, regardless of reasons why you would want to)? Is this the same reason why there is a minimum flush volume when tower is turned on? It all seems a bit unclear to me.

Thanks.

[ZundersHD]

BS is pretty selfexplanotary.

1a.: Black to White vs. Yellow to White bleeds not the same amount into each other, calculate does estimates the flush & therefore purge volume.
1b.: no, as you click the button.
1c.: no, the purge is stored in the program as distance extruded.
1d.: its using the default values for purge then.

2a.: regularly its placed near the poopchute, but sould be moveable.
2b.: or less travel from the purge to flush.

3a.: purge is poop, flush is the tower or the infill if selected.
3b.: wipe is scraping and shaking off the poop from the nozzle.

4.: no flushing no tower, so that doesent compute with tower active.

5a.: too little volume needed for that infill, so bleeding will occour on shell. so bs compensates that with more volume via a tower.
6a.: yes

[GalaxyRiver]

Thanks for trying to come down to my level.

Q1 I have worked out by trial and error. If you set the Preferences to auto-calculate it just means that everytime a new colour/filament is selected in the Filament area of Prepare, the flushing volumes shown and used in the Flushing volumes table change according to the new colour and the multiplier that has been selected. If you turn the Preference settings to off then you can change colour/type (accordingly) filament settings in slot 4, for example, and the previous number in the table relating to slot 4 will not change.

Q2 Thank you. It is movable; that was my mistake. As it acts as a wipe, my preference would be to have it closest to the print so that travel distance is minimised between wipe and printing to reduce the time that unwanted extrusion might occur.

Q3 Your answer makes no sense to me. When flush volumes are set high, lots of poop is produced. Therefore Flush volume can also be poop, it’s not just purge that is pooped. Without a tower, all flush is pooped. What are the definitions of purge and flush?

Q4 I didn’t understand your answer. Why can’t you have a tower and just a little bit of flushing? Why is there a minimum flush amount that does not appear to relate to the tower width, the prime volume and ignores the Flush volume setting when that setting is lower than a certain amount? What determines that threshold amount? Here I show examples:

Firstly, no tower, Flush volumes can be set down to zero - I have no problem understanding this:

Now with tower, let’s try low Flush volumes gradually increasing (Flush into object’s infill setting does not appear to change anything):

With the last settings above the reported Flush only now increases above that minimum fixed value of 46.70g. Any Flush volumes setting less than about 100 always shows Flush to be 46.70g. Why? This is not the amount needed to build the tower because that is shown under Tower. Let’s try changing the tower width and/or volume:

The Tower amount changes as expected, but there is no change to Flush amount and the above is the same Flush amount as without the tower (see first image) where Flush volumes are 105. Therefor the Flushed amount shown is independent of whether we have a tower or not. Indeed, the tower is for priming, not ‘primarily’ for flushing though my understanding is that it (and infill if selected) will be used for flushing when flushing volumes are set high enough.

As you can see, changing the tower width or Prime volume does not change the total Flushed amount. So why when having a tower at all is there a minimum fixed value of Flush of 46.70g? How is the 46.70g calculated and why is it necessary?

Q5 But BS allows us not to have a tower at all if we don’t want it, with zero flush values, so why do we have to have it just because we have selected flush into infill/support? If it were BS determining that we need a tower because there will be bleeding on the shell why does BS not insist on a tower when we have set Flush volumes to very low values which will cause bleeding, too?