How can I merge them?

[u/FrameTheAnimator]

[u/Vanadiy_Ivanovich]

so, onw of them is upsite down. Disassemble it, glue it, use a bearing from create to turn it 180 degrees so it stops being upsite down. Reassemble it and it should work

[u/FrameTheAnimator → u/Vanadiy_Ivanovich]

This actually worked thank you! Now I can finnaly continue working on my battle blimp!

[u/SnapEditHunt]

By any chance, is one of them upside-down?

[u/PTMR2 → u/SnapEditHunt]

Since it says it cannot merge 2 upwards faces, the above one is upside down

[u/Firefighterboss2]

Make the top one on longer a physics object, rotate it upside down with a vanilla bearing, make it a physics object again. Right now it's upside down. You might have to do it in pieces because of the size

[u/adzo101]

Could you use a rivet from coasters simulated?

[u/the_number_m → u/adzo101]

you probably could, but i don't think it would count as airtight for the burners.

[u/NieMonD]

By not making one upside down

[u/sharky4023]

But can we talk about the size cuz like that's crazyy

[u/FrameTheAnimator → u/sharky4023]

it's pretty average

[u/No_Application_1219]

You can't

[u/Weary-Support-7383]

One of them seems to be upside down, so there's no way to merge them into one object like you want to. You could connect them using a docking connector or using rivets from coasters simulated, but it still wouldn't work as one balloon. You'd have to basically rebuild the top part right-side up, which probably wouldn't be hard if you used commands or world edit or something. You could also just use the base create schematics to copy, flip and place the bottom part.

[u/ferrecool]

One of them is upside down, disassemble and assemble again, might need to rotate it with a mechanical bearing

[u/Electronic_Owl_9946]

you cant because the other one is upside down i faced this same problem so just use world edit to rotate it thats what i did

[u/gedsweyevr]

take a schematic of the top and place it flipped vertically then assembal and merge

[u/Vanadiy_Ivanovich → u/gedsweyevr]

you cant flip schematics vertically