Bug when skipping object?

Bambu Lab H2 Series
1

I was printing two vases on an H2D which had a tons of filament changes. I had a small and a big one on the same printbed and throughout the printing process, the large one failed. So I skipped it …

What still seem to happening though is, even though the small eventually finished, it kept changing the color and kept printing the prime tower.

Is there a setting I missed ? If this is expected I think it should either check if the prime tower after skip is actually still required or at the very least give the option to also skip the purge tower so I don’t waste filament on a prime tower needlessly …

2

Consider the following. The prime tower is built from a mix of filaments required for all objects on the plate.

The skipping is based on start and end of object numbers in the gcode, so if you decide to skip object number 1 it will basically skip the code of that object.

It currently doesn’t scan the remaining gcode to see if there are color switches expected on the remaining objects.

Simply discarding the prime tower or parts of it because that color belongs to the skipped object can result in greater issues further down.

So in my opinion this is not a bug. The primary goal of skipping an object is to save the objects that are still correct, not to save filament.

If your 2 vases are one with only one color and the other with lots of color, the first advice I would give you to print them separately anyway, because the color changes on one will have negative impact on the quality of the other due to different layer times and the shrinking of the material.

You could ask for an enhancement, but the complexity of the solution might only introduce more issues than it solves.

3

Before printing at the same time I did compare filament waste and printing time (individual Vs together).

4

Were both having multiple colors?

5

I was talking about quality when I proposed printing them separately.

If one vase has only one color, you are always better off printing that separately. The only lost time is the additional startup procedure.

6

In the case of the OP it’s not a matter of more colour changes - as all objects had finished - and all that proceeded was an unnecessary completion of the prime tower.

I guess in this situation you have to keep an eye on the print and cancel it as soon as the last object has finished printing - but I think stopping the prime tower after all still active objects have finished printing is a less complicated issue than stopping priming of individual colours - but I guess it is an even more niche requirement - so less likely to ever get developed by BL.

I do though think that they should develop a way of stopping unnecessary priming of cancelled colours - probably by just completing the structure of the prime tower with the current colour rather than switching to and out of an no longer used colour.

Or even better make the printer itself do the prime tower construction dynamically at run time - rather than doing it all in the slicer. (That’s what I am doing in my RepRapFirmware based printer).

7

Seems I misread that a bit.

I agree that this isn’t too hard to implement.

But trying to cancel out some colors from the prime tower is quite a challenge. Definitely because you can’t take any priming out of the tower.

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