I'm trying to install crown molding to hide a light I'm using for uplighting to provide indirect lighting in a stair well. A picture is attached. The longer side I envision against the wall, the shorter side out. The angle to get back to the wall is cut at a 45.
I'd like to attach crown molding around the outside to block the view of the light, and I need it to make the 45 degree angle as a corner. I've tried watching video's on youtube and I've tried to read the site installcrown.com but whenever I think I understand it I make some cuts and I'm left with nothing that works.
Using the calculator on the above site, I assume my wall angle is 112.5 (outside corner is 225 (180+45) and divide by 2)
spring angle of 52 (using it upside down to get a more favorable nailing edge and it still looks good
gives miter of 27.77 (28 for my sake)
bevel of 20 degrees.
I've made that cut and used up about 4 feet of cheap molding trying to figure it out and I can't.
Can someone please help me figure out what I'm doing wrong?
Thank you!

I'd like to attach crown molding around the outside to block the view of the light, and I need it to make the 45 degree angle as a corner. I've tried watching video's on youtube and I've tried to read the site installcrown.com but whenever I think I understand it I make some cuts and I'm left with nothing that works.
Using the calculator on the above site, I assume my wall angle is 112.5 (outside corner is 225 (180+45) and divide by 2)
spring angle of 52 (using it upside down to get a more favorable nailing edge and it still looks good
gives miter of 27.77 (28 for my sake)
bevel of 20 degrees.
I've made that cut and used up about 4 feet of cheap molding trying to figure it out and I can't.
Can someone please help me figure out what I'm doing wrong?
Thank you!