by stearmoth » Tue Sep 13, 2011 6:13 am
True aligning aileron trailing edge - that's what we all are looking how to achieve!
If you follow the aileron photo sequence on our website (click on the ailerons on the Hatz picture in the shop), you will find out how we tried to achieve this.
As our aluminum skins are very thin, we feared to rivet top and bottom skin as shown on the Waco pictures before. We rather made a sandwich with the angled aluminum sheet as shown on the plans and a spruce triangle stiffener. On the outer portion of the ailerons (where they are curved) we just glued in an curved aluminum sheet. We used an elastic two parts acrilic compound with better results that an epoxy glue (this is too brittle, the other is like rubber and stays elastic). The wooden triangle insert we made up to the tip (from the plans you couldn't tell where this stops).
The wooden insert was made from two parts and scarf glued flat together. We assembled then the aileron temporarily with clecos including the hinges and mounted it on the wing panel. At this stage only the top skin is accurately cut at the trailing edge. The lower skin is a bit oversize. Install a true edge (straight wooden plank) to the bottom rib flanges inboard the aileron, so that the aileron skin is supported properly (underlay some scrap between the rib flange and the edge to take care of the protruding aileron corrugations). We then put the wooden filler between the skins and shaped the triagle section of the curved wooden filler such, that there was a smooth flow up to the wing tip bow. We fixed the skins at the trailing edge with some clamps and traced the bottom skin trailing edge to follow the top skin. After this we made all the forming of the corrugation's ends (this is cosmetic and optional of course).
When all was fine we primed the inside of the skin etc. with epoxy and assembled the ailerons with this elastic compound and rivets, but no rivets yet at the trailing edge! Within the open time of the compound we installed the ailerons on the wing panel, supported it with the edge out to where the curved part of the aileron starts and attached the clamps as can be seen on the photos.
We are very happy with the result and find that way, the trailing edge is more resistant to handling (because it is as thick as the inner wooden trailing edge) , looks nicer and perfectly blends into the wing tip bow, which itself follows the wing ribs skelet line. Weight of the ailerons: top: 4.2 lbs, top: 4.4 lbs (everything installed).
We hope there is more help than confusion and good luck!
Hans & Sam, H.C. #78, Switzerland
True aligning aileron trailing edge - that's what we all are looking how to achieve!
If you follow the aileron photo sequence on our website (click on the ailerons on the Hatz picture in the shop), you will find out how we tried to achieve this.
As our aluminum skins are very thin, we feared to rivet top and bottom skin as shown on the Waco pictures before. We rather made a sandwich with the angled aluminum sheet as shown on the plans and a spruce triangle stiffener. On the outer portion of the ailerons (where they are curved) we just glued in an curved aluminum sheet. We used an elastic two parts acrilic compound with better results that an epoxy glue (this is too brittle, the other is like rubber and stays elastic). The wooden triangle insert we made up to the tip (from the plans you couldn't tell where this stops).
The wooden insert was made from two parts and scarf glued flat together. We assembled then the aileron temporarily with clecos including the hinges and mounted it on the wing panel. At this stage only the top skin is accurately cut at the trailing edge. The lower skin is a bit oversize. Install a true edge (straight wooden plank) to the bottom rib flanges inboard the aileron, so that the aileron skin is supported properly (underlay some scrap between the rib flange and the edge to take care of the protruding aileron corrugations). We then put the wooden filler between the skins and shaped the triagle section of the curved wooden filler such, that there was a smooth flow up to the wing tip bow. We fixed the skins at the trailing edge with some clamps and traced the bottom skin trailing edge to follow the top skin. After this we made all the forming of the corrugation's ends (this is cosmetic and optional of course).
When all was fine we primed the inside of the skin etc. with epoxy and assembled the ailerons with this elastic compound and rivets, but no rivets yet at the trailing edge! Within the open time of the compound we installed the ailerons on the wing panel, supported it with the edge out to where the curved part of the aileron starts and attached the clamps as can be seen on the photos.
We are very happy with the result and find that way, the trailing edge is more resistant to handling (because it is as thick as the inner wooden trailing edge) , looks nicer and perfectly blends into the wing tip bow, which itself follows the wing ribs skelet line. Weight of the ailerons: top: 4.2 lbs, top: 4.4 lbs (everything installed).
We hope there is more help than confusion and good luck!
Hans & Sam, H.C. #78, Switzerland