Issue description:

After upgrading to 1.15.2, it seems that Turbines can't be build anymore. After following construction steps from multiple sites (https://ftbwiki.org/Industrial_Turbine and https://wiki.aidancbrady.com/wiki/Industrial_Turbine) and trying different sizes, I am quite sure, the blocks wont combine into the turbine. I added multiple screenshots showing how I build the turbine. I also made sure, I didn't use vents instead of dispersers.
Every other structure is working properly.

Order I build the Turbine:

1. 5x5 Base of Turbine Casing
2. Shaft with 5 height and 2xRotors on every Shaft
3. Building outer frame and Rotational Complex
4. Pressure Disperser and part of upper Casing
5. Coils and Structual Glass
6. 2 Layers of Vents
7. Finished upper Casing (at this point it should build into the Turbine
8. Placed 2 Valves at the bottom

Forge: 31.1.63
Mekanism: 1.15.2-9.10.1.414

same issue 1.12.2 wasted 4 hours thinkin im the one making mistakes -.-

The top needs to be turbine casing, try adding another row on top.

I tried it, still not working (and it should work with Vents ontop)

By forming you do mean the multiblock sparkle and attempting to right click it opening a GUI right? Not the connected textures which requires the connected textures mod that doesn't have a release version for 1.15 yet.

Try making your turbine rotor stack a little shorter. It looks close to the edge- the turbine won’t form if rotor blades are touching (or almost touching) the sides.

@pupnewfster yes i mean the sparkles / hud
@aidancbrady makes no difference even at the height of 3 it won't work

So it turns out the turbine’s narrowness calculation is a bit bugged. Make your turbine either shorter or wider and it will work fine.

But even when I build a 9x9x9 Turbine (Shaft height 5) it wont build.

I've tweaked the logic of formation logic which should hopefully fix this (and similar) issues.

Just a suggestion as i ran into the same issue, i had 2 rows of vents ontop of each other. Once i made the top layer only vents it worked. May be wrong but i had to reduce my vent to the layer after saturation vents. Vents are still visible but purely 3 layers, pressure-saturation-vents