Dec 15, 2021     Stabilator - (3 hours)       Category: Tail Feathers

No picture this week... I spent a few hours measuring and remeasuring the placement of the ribs on the spar. This came about as I was cutting the pieces for the trailing edges of the stabilator. I thought the easiest way to get the correct measurements (vs from the drawings) was to measure the markings I had made on the spar from the plans last time to position the ribs. WOW the two sides were not symmetrical! So I slid all the ribs off the spar and looked back at the plans and my marks. First I measured my spar - it was exactly 84 1/16 th inches - so I used my chop saw and trimmed the extra 1/16th off. The I added up all the measurements on the plans. form left to right it reads "10"+10"+10"+8 1/8"+7 1/4" +8 1/8" + 10"+ 10" + 10"... I added these up on the calculator and it came to 83 1/2 inches? So now the "head scratching" began. If I missed adding in all the 1/4 " widths of the ribs then it would add eight 1/4" widths. so definitely adding 2 inches to the spar is not right (85 1/2 "). So rereading the plans and looking very closely at the markings on the 11"x17" plan book I saw that the "7 1/4 inch" center measurement is an interior dimension vs the 10" measurements are all from the exterior of the ribs. This led me to realize the 1/2 inch difference was from the widths of the two interior ribs. Perhaps later I will add in a scan of the plans page that gave me so much "head scratching". Took a picture of the page.