Iflylower
Registered User
Memphis, TN
Here is one for the home builders....
I made all my own leading edge skins for the wings, excepting the the last wingtip skin for each side. Those compound curved skin are not easy, and Univair charges $200 per.
I used a vacuum press process I learned on Youtube. Look it up for clarification.
Anyway, I made the skins out of .020 2024t3 and that is some springy material. They turned out great. I planned all the skins based on prints. I made them the correct length and width. (a little over on width can give you some play room. Trim later on the wing.)
Get some length of 2" pvc, buy a cover for one end, and a coupler that fits your vacuum for the other. The tube length doesn't matter much. Take a section just smaller than your smallest skin width and drill 20-30 holes into it. You want air to be able to move. A roll or two of GOOD 3M duct tape. I had two kinds and the cheaper stuff would seal the plastic, but not hold the 2024 closed.
Figure your leading edge point. Make a mark on the center of what you'd call the apex of the skin where it fits the wing leading edge. Tape that mark to the 2 inch pvc. Now, lay the trailing edge of both skins (upper n lower) to where they should meet together. NOTE: The top half should always be nearly couple inches longer than bottom. Do your own math like I did. I did this eight months ago.
Tape the sides by the rear corner together as this does a better job of locking the upper and lower than a flat piece on the trailing edge. You're gonna tape that trailing edge too, but experience will show you that your tape will not hold the halves together without those "lock" pieces in place. 2024 wants desperately to stay straight. Honestly, this wasn't always easy, but it did turn out well. Start with the smallest skins first, as they are the easiest. The longest skin has the most bounce back and can be frustrating.
Now tape plastic around the sides of the pvc tube and sides of the skins. You want NO air gaps between the inside of the skin and outside. Make it air tight, cause you're gonna vacuum it.
Once you're sealed, turn on the vacuum and watch it all squeeze in on itself. The skin will form right around the 2" pvc and the rest of the skin will lay flat, upper and lower together. I flatten it, shut off the vacuum to release, turn it on and repeat a couple times to lock that form in.
After you've done it, untape. You should have a nice "L" shaped curved leading edge skin. You're ready for the brake to put spar bends and fit to wing.
Please reference Youtube for videos to clarify the procedure. You can tell this is a "clean" process as I did it in my kitchen area in February.
Somewhere, I have better pics of the process, but can't find them. Notice a couple finished skins next to the vacuum.
Enjoy! This is a money saver for the homebuilder.
I made all my own leading edge skins for the wings, excepting the the last wingtip skin for each side. Those compound curved skin are not easy, and Univair charges $200 per.
I used a vacuum press process I learned on Youtube. Look it up for clarification.
Anyway, I made the skins out of .020 2024t3 and that is some springy material. They turned out great. I planned all the skins based on prints. I made them the correct length and width. (a little over on width can give you some play room. Trim later on the wing.)
Get some length of 2" pvc, buy a cover for one end, and a coupler that fits your vacuum for the other. The tube length doesn't matter much. Take a section just smaller than your smallest skin width and drill 20-30 holes into it. You want air to be able to move. A roll or two of GOOD 3M duct tape. I had two kinds and the cheaper stuff would seal the plastic, but not hold the 2024 closed.
Figure your leading edge point. Make a mark on the center of what you'd call the apex of the skin where it fits the wing leading edge. Tape that mark to the 2 inch pvc. Now, lay the trailing edge of both skins (upper n lower) to where they should meet together. NOTE: The top half should always be nearly couple inches longer than bottom. Do your own math like I did. I did this eight months ago.
Tape the sides by the rear corner together as this does a better job of locking the upper and lower than a flat piece on the trailing edge. You're gonna tape that trailing edge too, but experience will show you that your tape will not hold the halves together without those "lock" pieces in place. 2024 wants desperately to stay straight. Honestly, this wasn't always easy, but it did turn out well. Start with the smallest skins first, as they are the easiest. The longest skin has the most bounce back and can be frustrating.
Now tape plastic around the sides of the pvc tube and sides of the skins. You want NO air gaps between the inside of the skin and outside. Make it air tight, cause you're gonna vacuum it.
Once you're sealed, turn on the vacuum and watch it all squeeze in on itself. The skin will form right around the 2" pvc and the rest of the skin will lay flat, upper and lower together. I flatten it, shut off the vacuum to release, turn it on and repeat a couple times to lock that form in.
After you've done it, untape. You should have a nice "L" shaped curved leading edge skin. You're ready for the brake to put spar bends and fit to wing.
Please reference Youtube for videos to clarify the procedure. You can tell this is a "clean" process as I did it in my kitchen area in February.
Somewhere, I have better pics of the process, but can't find them. Notice a couple finished skins next to the vacuum.
Enjoy! This is a money saver for the homebuilder.
