Can't move or merge primitive to a cut part with connectors

I cut a large model into multiple pieces to fit the print bed, and added connectors during the cuts.

On some of the cut objects, I now want to add a bit of filler to smooth out overhangs and reduce support needs on certain areas. So I was trying to add a primitive part into the original cut object.

I can right-click on the previously cut object and select Add Part and it adds the shape I choose as usual.

However, the only thing I can do with that added primitive part is drag it around on the X & Y axis on the plate. I can’t move it in the Z direction, and I can’t scale it. Most of the toolbar options are grayed out when I have the added part selected.

I can add a negative part and move and scale that freely. I can even change the negative part to a normal part, and it stays where it was and the scale it was as a negative part, but again, most of the toolbar items gray out when it’s changed to a normal part.

For now, I’m using that as a workaround; Add negative part, move/scale as needed, change to positive part.

I’ve also tried adding a whole separate primitive object and then merging into the other part’s assembly, but when I select the original object and the new primitive object, the merge option is missing.

(Side note, I was originally going to use negative parts to try to smooth out some of the overhangs, but parts of the model are too thin to remove material, and other parts are really tough to get in to a tight spot and get a negative part positioned exactly right. So then I thought I could add material to smooth out angles. I think the little material I add would still be less than supports in areas where I don’t need them.)

This is usually done in Blender or a CAD program, since Bambu Studio doesn’t really offer any decent options for this. One way would be to export your cut model as an .stl file and edit it in another program. But to stick with your approach:


First, click on (1) the added prim, then on (2), and then you can move it as high as you want. You can also scale it.

Make sure they’re in a group; otherwise, it won’t work. Take a close look at the picture; everything is grouped together at (3).


Edit: Added a second image.

1 Like

Thanks for the reply. Unfortunately, I’m not very well versed in CAD. I’ve dabbled, but I’ve done things like this before in Bambu Studio, so it’s what I know.

I have done this many times before for other things. Here’s my screenshot. It is a group, but see how the toolbar items are grayed out when I have the primitive item selected? I can click directly on the cube and hold down the left mouse button and move around the X & Y on the plate, but I can’t even scale it.

I can add the primitive as a negative part, and everything works as expected.

The only other thing I can think of is that it has something to do with the cut connectors. If it matters, I did dowel connectors. I do see one difference in mine from yours, is that I have a “Cut connectors” item with each of my cut objects, which are the dowel holes for that object. I see the connector pegs on yours, but don’t the “Cut connectors” item that I have.

I wonder if the dowel “Cut connector” holes are messing up the relationship with the added primitive.

In my case, my Connector-1, etc., parts are the standalone dowels.

I just went back to the original uncut model, and this all works fine. So, it must be something related to the cuts, and potentially specifically the dowel connectors. But I’m only guessing.

Okay, I was able to reproduce the problem: Bambu Studio apparently has issues with certain objects and won’t let you make changes, but there’s a simple solution:

After cutting & connectors, click “Export as one STL.”

Then you can reinsert it, preferably onto a second plate:

problem solved:


However, don’t ask me why Bambu Studio does that. Sometimes, Studio had no problems; at other times, it did. Is that the better way? I don’t know…

Thanks for the workaround. I’m getting by with using negative parts to move into position and size, and then changing type to a normal part. It’s just harder to see that it’s in the exactly right position with the shadow vs. the solid part.

If I get too frustrated, I’ll probably try your workaround.

Thanks again!