Hatz Biplane Association

I'm in the process of constructing my wingtip bows. Drawing 7 shows how the wingtip makes an arc if looked down the long axis of the wing. Have any of you built them this way? I have seen how some have built the bows by laminating strips in a vertical orientation and then gluing these laminations to the 1/8" wing tip bow core. Drawing 10, however, shows laminations on the 1/8 core placed in a horizontal orientation. Seems that if done this way, you could create the arc as shown in drawing 7.

Just curious if anyone has built their wingtips with that arc. I've got an idea of how I would do it, just not sure if it is the norm.

Thanks in advance. Man, is this fun or what!


Jeff Orear
Peshtigo, WI

I'll take a stab at this since there's been no replies...

I built my wing tips flat and installed them at an upward angle. So when I sight down the long axis of the wing, the tips appear to have an arc similar to what you see on drawing 7.

Remember, if you build your tips with an arc, then slant them up during installation, they may not match the spars.

I could be wrong on all this but at least I took a crack and answering the question

-Scott

I built my wing tips flat by laminating 1/8 strips together in a fixture. I later cut them down the middle and bonded them to the 1/8 plywood center piece that would fix them to the spars. I made them about 2.5 inches thick so that I could later sand the arc into them with a disk sander. It made a huge sawdust mess but I think it worked out OK, of course I am a long way from being done. I just finished the top wing last night and I hope that the two wing tips look similar.
I am debating on whether or not to add an extra rib after the last compression strut to give the wing a little more shape into the bow, it seems a little flat.
Scott, If you read this, whose lights did you use on your wing tips? I would like to do something similar.

-Ed

Thanks for the replys. Angling them up makes sense, Scott. Isn't that angle predetermined by the 1/8" slots cut into the leading edge, main, rear and aileron spars? Is there some wiggle room here?

Scott. Isn't that angle predetermined by the 1/8" slots cut into the leading edge, main, rear and aileron spars? Is there some wiggle room here?

The slots must line up, at least it seemed that way to me. In my opinion, there is very little wiggle room


Bitshifter:

Bitshifter wrote:Scott, If you read this, whose lights did you use on your wing tips? I would like to do something similar.

-Ed

The lights are available from http://www.kestrobes.com or from Aircraft Spruce at
http://www.aircraft-spruce.com/catalog/ ... kkey=27339