Drywall 90 degree curved/fillet ceiling support boning rib

They sell kits for this, but they are expensive, and were too thick to go around the protruding pipe in my ceiling. So I whipped up this simple support rib so I could make the curve low-profile, and re-use some of my spare drywall at the same time.

Each rib takes around an hour to print using a 0.8 nozzle and 0.32 layer height. I am using PLA+ for this.

Usage Steps: 
1. Cut a piece of drywall that is the correct length for your wall, and approximately 44cm (17.5 inches) wide. (You can also use flexible sheets to get a smoother curve and avoid having to remove the top of the existing drywall! Skip to step 3 in that case!) 

2. Score the BACK of the drywall to create an odd number of 4cm (1.5inch) segments along the length of your piece, with longer pieces on the edges.  
For a 4cm spacing, you should have 9 segments (8 cuts) with the following width pattern (cm):
8-4-4-4-4-4-4-4-8 
(The sample picture only show a piece with 4cm at each edge, but you'll want it longer (8cm) for easier attachment to the studs in step 6!) 

3. Drive a standard drywall screw through the centre of the centre segment (bolded above) and into the provided centre-hole on the printed rib. 

4. Using ‘liquid nails’ (or any other drywall glue), adhere the remainder of the segments to the inside curve of the rib. 

5. Repeat at approx 30cm (1 foot) intervals along the length of your scored drywall 

6. Using the 2 outer segments of drywall (8cm), affix your fillet/curved segment to the studs on your wall and celing. Cut away any other drywall at the edge/top of your wall and affix directly to the studs! (unless you are using a flexible sheet, in which case, just put it over the existing drywall and use drywall tape to make the transition) 

7. Using drywall mud, smooth out the segments in your segmented curve to look more gradual. Tape and mud the edges to the existing pieces of drywall.