When you're done with the tip, is should have this cross section... Sorry the picture is kinda lousy, but it's the best of about 5 I took so... get over it...

Well, I got bored with gluing things together, so I decided to go on with carving my first tip. When I get bored, I use these kinds of challenges to keep me fresh. I had forgotten how pretty this wing can be. Mine'll be transparent orange and white with some chrome and black trim.

... about what you see on some moldies, and on most of the full-scale German stuff, if not equipped with winglets... close enough, anyway. Some have called them positive Horner tips, but I believe that's a mistake. The Horners were somewhat like this, but shorter span wise, and more for a square wing.

... and that's all for tonight. Midnight crept up on me last night... If the weather cooperates tomorrow, I'll drag out the table saw and join the other outboard set, and cut the angle for the inboard end of both intermediate panels. I'll also start laying out the center panel. If I have time, I'll cut and bend the joiners, too.

I've started working on the center section, but won't post any more stuff for about a week. We're leaving for Christmas tomorrow and I have to get ready for that.

Merry Christmas everyone...

Jack

This is important... the cross section of the shear web must be shorter at the aft edge than at the front edge. These must fit very near perfectly. There must be no voids between the shear webs and spar caps. Sorry the picture is blurry... but you get the idea.

The center portion of the panel must be built without the lower sheeting at first so it can be wrapped.

This piece of spar assembly then gets wrapped with Kevlar tow. Be sure that the corners of the carbon spar caps are slightly rounded to prevent cutting the Kevlar under stress.

The rest is pretty straight forward after that. I am trying different things in between the feathered trailing edge sheets. On this panel, I used 2 strips of the .007 X .25 cf. It's a little bit better that the .2 oz. cf tissue I used on the intermediate panels. The webs are joined and sanded, but it was too cold tonight to mess with the epoxy. Don't forget the bottom cf strip fo rthe D-tube reinforcement.

Notice the spoiler tubes. I probably stated earlier that this ship would have one spoiler servo up front like the Hawk. I had wondered how to get this done effectively. The tubes exit directly through the leading edge. I drilled the holes at an angle so they exit about 1/4" apart. The wood canopy will cover this area so it's not a problem.

Had a while this afternoon after getting back from Ft. Worth. Thought I'd catch up a bit.

Enjoy...

Merry Christmas!

Jack Womack

Oh... one more thing. If you do run spoiler tubes, be sure to use the smalll tubing and drill a SMALL hole, no bigger than 3/32", on the centerline of the shear web... Back to that no voids in the spar thing. More tomorrow while waiting for kids... if it warms up a tad...

Wow, hard to believe you are the only one posting to this thread. Just letting you know I am following it too...

Jay

Note: just saw that I wasn't supposed to post to the thread... sorry about that, if you need to delete this post please do so...

Originally Posted by schrederman

Oh... one more thing. If you do run spoiler tubes, be sure to use the smalll tubing and drill a SMALL hole, no bigger than 3/32", on the centerline of the shear web... Back to that no voids in the spar thing. More tomorrow while waiting for kids... if it warms up a tad...

I have been using this method of actuating spoilers for 30 years. On 3 piece wings, I exit the wing through the bottom just aft of the spar. Takes a little care in working around the forward bolt but not hard to do if you plan ahead.

I decided to avoid the area under the wing with the spoiler tubes in order to build a ballast box there. It'll be clear as mud when we get to that point...

JW

Your build is sure making me want one!!

Would you mind posting the details of the spoiler setup for the new builders (me) - here or the other Yardbird thread?

Thanks,

Mike

OK, here we go. As I said, we'll discuss sanding quite a bit here. I am going to show you the spar bumbs and how to know when they're gone. If you want to kill the performance of this glider, ignore this step...

Photo # 1 is of the wing section that hasn't been sanded. The section in photo # 2 has been carefully sanded with Behr 3X 150 grit sandpaper on my aluminum block. Again, the block needs to always be parallel to the spar and the strokes need to be at 45 degree angles. The only pressure needs to be the weight of the block. If you sand parallel to the spar, you may sand flat spots on the wing. If you sand straight back and forth chordwise, you'll sand grooves in the sheeting. Too much pressure and you'll sand too thin or even through at the ribs.

Let me know if there needs to be further clarification on that one. Please use patience here. This is where great covering jobs begin.