Composite Leading Edge

[HighWing]

Another idea on the cutting, the Lancair guys used diamond discs for their dremel tools. Also available at Harbor freight. Then a possible touch up with a sanding drum.
Lowell

[jrevens]

How are people handling rib-lacing with the Laker leading edge? Are you starting the lacing where the fiberglass ends? Since the fabric will be glued to that large surface area on the top, would lacing still be desired over the Laker leading edge (by drilling holes in the fiberglass)? My guess is that it might negate some of the aerodynamic improvement by doing that... true? If starting the lacing after the fiberglass, would you still lace the bottom all the way forward, catching only the bottom section of the rib in that area? Thanks in advance for any comments.

[HighWing]

John,
I don't think lacing would be necessary. It would be similar to how the fabric is handled on the top of the fuel tank. That said, though, I put aluminum on top of the leading edge essentially a poor man's LLE. I just used the two coats of Polybrush on the leading edge, then shrunk the fabric and applied the fill coat of Polybrush over the wing. I did pick up the lacing about two inches behind the aluminum skin.

[Av8r3400]

Lowell - Are you getting any oil-canning from the flexing of the wing with this setup?

[HighWing]

Lowell - Are you getting any oil-canning from the flexing of the wing with this setup?

Larry,
I guess the short answer is - I don't know. When we were thinking of this, I remembered Hal who at the time flew an early Rans S-7. He would often get oil canning while on the ground. When it was pointed out to him, he would grab the wing tip and with a big grin, shake the tip and the wing would pop straight.

I decided I needed it straight on the ground to void people pointing out my crooked wing. When building, I supported the wing at the root end and at the lift strut brackets so it would be in it's typical unloaded ground geometry and hopefully lie straight when people could see it. I riveted a "Z" channel at the trailing edge of the aluminum as a stiffener there and the Z loosely captures the stringer that would normally support the aft ends of the false ribs (I eliminated the false ribs entirely to help compensate for the weight of the aluminum). The one thing I overlooked in my planning was the weight of full tanks while on the ground. On rare occasions, the bay immediately outboard of the right wing tank will show a slight depression near the trailing edge of the aluminum, but not consistently and it is only visible from the vantage point of a ladder.

The "I don't know" part of the answer really refers to what it looks like in the air when it tries to flex and assume other than the at rest geometry. With that in mind, though, it does seem to fly better - but that might be akin to how much better a car feels after washing it. One definite and measurable improvement is full power stalls - much more stable, not the violent wing drop I used to get with my first Model IV. Sorry for the quality of the attached image, but it shows the general appearance while on the ground.

[jamesmil]

would like to post my 2ct, worth on the instalation of the laker leading edge.
we used avation snips to do all the cutting as the fiberglass is very thin and we just made a stright cut top and bottom with no scallop. also we started the rib stiching after the l/e.
to lay out a stright line we slid the l/e on the wing then got a mark at each end and used masking tape to lay the line stright, if you use this method to get your stright line make sure to mark the tape with arrows to show which side to cut. no i didn't do it this time but it is very expensive to learn the hard way.

[Esser]

Are the scallops just for aesthetic purposes?

[mr bill]

I did not scallop my leading edges and there is not a pronounced "edge" under the fabric. Using the Stewart System adhesive was new to me, but I liked it being water based, very strong bond and easy to get off your fingers.

[jrevens]

I see that there is a water-soluble transparent coating of some sort on my Laker leading edges. It's kind of a mess getting it off. It's very thin, and some of it stripped off when removing the tape used for shipping. Anybody else notice this?

[AirFox]

Your suppossed to use soap and water to wash it off. The film just disolves.

Scott