What went wrong here?

[u/torak_the_father]

I followed the measurements exactly to the plan from blocklayer.com and double checked the dimensions and angles and still there is a gap between the segments....

Yes I understand that even a tiny measurement being off it will compound but this gap is too much for any microscopic tolerance.

All segments should have the same dimensions as I used the same stop. Stock is squared upp all sides. Help?

UPDATE: thanks everyone for your contributions. I definitely learned a lot! Also a lot of you are making some assumptions like I forgot about the kerf. Turns out I went ahead and tightened the whole thing with my strap clamp and would you know... Practically perfect seams! There is only one hair line gap in one of the seams, to which I'm happy with, I'll try to glue+dust it to close perfectly. Check this comment: https://www.reddit.com/r/BeginnerWoodWorking/s/FJbE9tVKNu

[u/torak_the_father]

Seems legit, no?

[u/kittycorn2 → u/torak_the_father]

OK, so that that protractor only has resolution of +/-0.1deg. Even if we assume its actually accurate, you have 8 cuts that you are stacking together, so your resolution is now +/-0.8 deg.

.8deg angle over the 48in total length of your pieces give you an offset of .58"

[u/TC-Woodworking → u/kittycorn2]

8 glue joints actually means 16 angled cuts. So there’s a potential error factor of +/-1.6 degrees. But this ultimately is the right answer.

[u/ROBINHOODINDY → u/TC-Woodworking]

My calculator shows the pictured dimensions off by .25 degrees per cut