Today the bulkhead rings I designed arrived from the waterjet. The rubber gaskets will probably arrive soon. These go on each end of the 8 foot aluminum tubes that make up the wing tanks, one tube for each wing. It cost me roughly $170 after shipping to get these 10 rings cut along with the rubber gaskets. I will make the bulkhead plates on my cnc mill out of .050 5052 when the time comes. I made the rings the same diameter of the pipe so that I could clean them up after they arrived. The waterjet process leaves a sandpaper texture, so it's always a good idea to make holes a little bit smaller and the parts a little bit bigger than required. All the holes are drilled out and tapped for #10-32 screw, 10 per ring. I used the drill to thread the holes, doing those by hand would take too long, be sure to use cutting oil. The Lathe is also useful for deburring, facing and filleting the sharp edges, not to mention shave a few thousandths off the diameter. Here I've done 2 rings, I will need to do 2 more (assuming I don't screw up!).
