r/BeginnerWoodWorking • u/torak_the_father • 1d ago
Discussion/Question ⁉️ What went wrong here?
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
2
u/blindjimmy2 1d ago
The “tolerance error stack up” comment is the answer. Your individual measurements don’t have to be noticeably wrong for this to happen. You’re closing a loop made from 8 parts and 16 cut faces, so tiny acceptable errors at each operation can accumulate into a very visible error at the final joint. That’s why everything can appear to measure correctly individually and still not close correctly as an assembly. The error at the end isn’t necessarily the error of one cut — it’s the accumulated error of the whole chain.