jt2hunt said:
I don't see pictures of your miscalculations!
So ...
I have a small project notebook I use to write down calculations, measurements, etc. so I don't have to remember them, re-measure, etc. At some point I wrote down an incorrect measurement for the barn doors. Everything about those doors was based on that measurement. It was wrong. Very wrong. like 8-5/8 inches wrong.

What I was going to do was make them asymmetrical because a narrower right side door would overhang the edge of the building less, but after I installed the left side door, I realized it made more sense if the left door overlapped, not the right, as was in the original configuration. Having to resize the door gave me a chance to fix it, so I decided to resize both doors.
This involved removing the exterior trim, interior side sheathing, and mending plates and screws at the corners, then prying off the frame stile and cutting the frame rails and insulation. After that, I reinstalled the frame stile and interior sheathing, trimmed the sheathing on both sides and reinstalled the trim. I used a flush trim router bit for a perfect fit of the sheathing.






I still need to add door stop trim inside so the doors don't swing too far in and cane bolts to secure them, but they turned out nice. I'm still mad I lost an entire day screwing around with this. It is the first significant mistake on this project that resulted in work having to be done twice.
Adding insult to injury, I installed the ceiling fan that was originally in the cabin this evening ... and it doesn't work. Shame on me for not testing it before it was removed on the first day of the project a year ago.