[Feature Request] - Prime towers In per Object printing

PiperMakes · July 19, 2025, 12:00am

I have an interesting use case that I tried brute forcing today but to no avail.
I’m trying to print assemblies with the H2d taking advantage of the two hotends to do 2 color prints. As an example I’ve set this plate up to illustrate what I mean:

I have two object groups here, and when set to print By object, the slicer will no longer print with a prime tower. This causes under extrusion on any of the times the hot ends swap resulting in this:

This will often ruin the supports or whatever the second filament is starting on.
Versus the same print but with a prime tower:

(This however means I can’t load multiple assemblies with different dual color setups on the plate.)

So I’m requesting the ability to set a prime tower up per assembly group as shown in the initial image, or to designate an object in the assembly as a prime tower. I was almost able to brute force this, but the slicer always wants to put the supports down first, defeating the purpose of the blocks I’d added to the assembly as a prime tower. I’m honestly not sure why this isn’t a feature, but I am very much hoping this gets added to later versions of the slicer.
If anyone has a way to get it to do this, or a solution, I’d love to hear it.

Thanks,
~Pipes

hotellonely · July 19, 2025, 12:32am

I requested the same on GitHub, no response yet tho…

hotellonely · July 19, 2025, 1:27am

github.com/bambulab/BambuStudio

Allow 2 Prime Towers to be generated

opened 05:28AM - 09 May 25 UTC

hotellonely

feature

**Is your feature request related to a problem? Please describe.** For H2D, the …print area is splited into 3 zones, left nozzle only, common area, and right nozzle only. If a large print (for example, Hue Forge or Light Box prints) takes up the common area and utilizes the dual nozzles, it would be beneficial to allow us to place the prime tower in Left Only or Right Only area, so that the common area can be fully utilized for printing. However, due to the physical restriction, a single prime tower would not be good enough. Thus if the slicer can generate 2 prim towers for each nozzle, putting into each nozzle's restriction area, then it would provide lots of freedom for creation. **Describe the solution you'd like** Allowing placing 2 prime towers into each nozzle's restriction area. **Describe alternatives you've considered** Can't think of an alternative approach. At least not for H2D I think.

give me a bump here

MagicElf · April 9, 2026, 5:58pm

Since I can’t embed media or links to the direct page, here’s a copy and paste of the verbiage from a wiki on this:

2. The prime tower only supports a unidirectional increase in Z height, so even if some layers do not switch filaments, the prime tower must be printed to ensure that it is consistent with the model height. It cannot be enabled in by-object printing mode.

MaxThreeD · April 9, 2026, 10:06pm

That’s probably why this thread is labeled “feature request.”

But thanks for bumping it so I could upvote, FWIW (at GH also!). A prime tower per object [group] seems like a reasonable solution (unless I’m missing something).

-Max

Gerrit · April 10, 2026, 4:59am

Technically I don’t see any issue as long as the grouped objects with it’s included tower is collision free from the other groups.

MagicElf · April 16, 2026, 11:14am

I’m new to this, so when I read this as a problem, I went searching through Wiki to help find a reason for the prime tower not to print. My apologies for not realizing the purpose for “feature request”.