New and Improved

EAA 143 has changed its meeting time from the fourth tuesday to the fourth Saturday at 9:30 a.m. This will hopefully accommodate member schedules better, especially since many of the members are already here for the glider project work day that occurs every week from 9:30 a.m. to 12:30 p.m.  Yesterday was the first such meeting, and I took the liberty of taking a picture of the attending members, minus myself--someone had to click the shutter :-)

Also, Irene came to the meeting (the hurricane), so numerous members didn't attend because they were battening down their hatches.

These are the attending members of EAA 143, minus the photographer :-)

A rib, is a rib, is a rib--or is it?

Problem: we didn't have a drawing for one of the ribs, the rib just inboard the aileron.  Joe Miller has a CD with lots of drawings on it, so he spent this past week looking at ribs.  Guess what, he found the missing drawing.  The photo above shows the necessary details, albeit a bit too small.  So, his next task is to send it out for enlargement.  

On a broader note: I hope you survived the hurricane with minimal inconvenience, and no damage to family or property.  Take care, and see you next week.

Interchangeable parts

Eli Whitney would have been proud.  

Using a pattern, these nose pieces have been marked, cut, and sanded.  They are ready for assembly into a wing rib.  Doesn't it give you a sense of satisfaction to see these precision made parts, each exactly the same (within engineering tolerances), so Leo and John can grab one as they need it and build a new rib.

BTW, I wanted to let everyone know, just in case you haven't heard.  Our EAA meetings are being moved from the fourth Tuesday to the fourth Saturday (at 9:30 a.m.)  So, if you want to come out and visit, you will be able to attend the meeting, and then watch the guys in action as they work on the glider.

A holey calling, gusset technology

The circular gussets were cut from thin plywood.

Some times the gussets are simply rectangular in shape, but in this case they are circular (same strength, but less weight).

Leo is cutting a circle from the plywood.

Leo found that the suggested method of stacking and clamping multiple layers of thin plywood did not work well.  The method he found the most success with was clamping one sheet of plywood and drilling a single gusset at a time.  Two sized hole saws are used: 3 1/5 inch for the large gussets, and 2 1/8 inch for the small gussets.

Leo is cutting the features in the gusset.

Each gusset must be trimmed to the application.  Many are simply cut in half, but some must have  notches for spars, etc.  The jig saw saves a lot of time.

Leo is showing John how to sand the rough edges that the jig saw left,

or is John supervising Leo?

Finished gussets, nice job Leo!

Tip rib with tubing cutout (cont.)

Tip rib with master nose piece

As you can see, the hole for the tubing is clearly marked on the master nose piece.  When taking this picture, I accidentally placed this rib nose piece against another, and guess what...

Ops, they don't match...huh?

Well . . . Joe, Leo, John, and Dick are not likely to make a mistake of this magnitude.  It makes sense that the wing tapers at the tip rib.  Thinking about it, it makes a lot of sense when realizing that the goal is to taper the wing to the thickness of a pipe that fits the little hole in the front of the rib nose piece.  Speaking of that hole, how do it get there?

Dick is marking the position of the hole in the nose piece.

Dick is drilling the hole, and will sand the rest of the hole to make it a slot.

So it seems that quite a bit of work is involved in tapering the wing.  Is it worth it?  Let's just say that the vortices gremlins are not nice guys, and drag is a gliders worst enemy.