RVbySDI
Well Known Member
Working on the RV14A fuselage. Page 29-06 calls for using a digital level to put a 10 DEG twist in the upper longeron.
![plans 29-06.jpg plans 29-06.jpg](https://vansairforce.net/data/attachments/15/15908-d5f50a2e30f948d4a465bb7d5d8927e6.jpg)
Well, I don't have a digital level. So how do I measure this? Let's see, what do I have that will give me a measurement? I do have a bubble level. I also have a very old carpenter's protractor that works very well. I also just so happened to have a metal shelf just laying around that happens to be perfectly square. I have tables that are perfectly level. Putting all of those tools together and securing with some clamps I came up with a system that looks like this:
![Carpenter's protractor1.jpg Carpenter's protractor1.jpg](https://vansairforce.net/data/attachments/15/15909-c4ee941ff6a8af8305ca2f62b6f4bb03.jpg)
![Carpenter's protractor2.jpg Carpenter's protractor2.jpg](https://vansairforce.net/data/attachments/15/15910-63eb7fe78c92268ee7a8111a182fe46d.jpg)
After building the small wooden blocks called out in the plans I got busy twisting the longerons. I made sure the side face of the longeron was plumb, the metal shelf was level, and my protractor was set for 10 DEG. Twist away! A few more twists! Ok, a few more twists! Finally, we get:
10 DEG!
Digital Level? WE DON'T NEED NO STINKIN' Digital Level!
![10 DEG on the firewall.jpg 10 DEG on the firewall.jpg](https://vansairforce.net/data/attachments/15/15912-eefa243f6742fcb7009c163a0a47b986.jpg)
![plans 29-06.jpg plans 29-06.jpg](https://vansairforce.net/data/attachments/15/15908-d5f50a2e30f948d4a465bb7d5d8927e6.jpg)
Well, I don't have a digital level. So how do I measure this? Let's see, what do I have that will give me a measurement? I do have a bubble level. I also have a very old carpenter's protractor that works very well. I also just so happened to have a metal shelf just laying around that happens to be perfectly square. I have tables that are perfectly level. Putting all of those tools together and securing with some clamps I came up with a system that looks like this:
![Carpenter's protractor1.jpg Carpenter's protractor1.jpg](https://vansairforce.net/data/attachments/15/15909-c4ee941ff6a8af8305ca2f62b6f4bb03.jpg)
![Carpenter's protractor2.jpg Carpenter's protractor2.jpg](https://vansairforce.net/data/attachments/15/15910-63eb7fe78c92268ee7a8111a182fe46d.jpg)
After building the small wooden blocks called out in the plans I got busy twisting the longerons. I made sure the side face of the longeron was plumb, the metal shelf was level, and my protractor was set for 10 DEG. Twist away! A few more twists! Ok, a few more twists! Finally, we get:
![10 DEG ready to go.jpg 10 DEG ready to go.jpg](https://vansairforce.net/data/attachments/15/15911-29a1cae1b4a219386a9e70e472e453af.jpg)
10 DEG!
Digital Level? WE DON'T NEED NO STINKIN' Digital Level!
![10 DEG on the firewall.jpg 10 DEG on the firewall.jpg](https://vansairforce.net/data/attachments/15/15912-eefa243f6742fcb7009c163a0a47b986.jpg)