Lincoln Log Wing

Can someone tell me which issue of Stunt New has the Lincoln Log Wing article. Tom's web site does not show the dimensions of the three piece LE, TE and jig, clearly, due to the low resolution of the JPeg.

May/June '97. A few issues later, some genius came up with the idea of 1/64" plywood "spine" in the LE & TE (instead of 1/16" x 1/2" balsa), in which he left gaps for the hinges. No hinge slots to cut...what a concept! Steve

Or you can get competely crazy like I did and come up with a variation on the theme.

Randy,

Where did you get the angle brackets for your jig and what is the base made from?

Tell us newbies all about it please?

Kirk,

The uprights are aluminum angle stock (6"x4") and the base is melenite (sp?). Basically formica sheeted particle board. Not too tough to build but tedious to insure squareness.

>Kirk,
>
>The uprights are aluminum angle stock (6"x4") and the base
>is melenite (sp?). Basically formica sheeted particle board.
>Not too tough to build but tedious to insure squareness.
>
>

Randy Powell

Randy, did you mill the aluminum angles so they are really square, or leave them as extruded? The reason I ask is that extrusions are seldom very square (or straight, for that matter). PITB. Steve

Steve,

The sides and face of each piece was milled to insure squareness. 38 pieces in all (which is where the tediousness came from). 16 for the wing, 12 for the stab and 10 for the fuse. This allows 4 base pieces to be fit together and squared up and the entire plane to be fitted in the jig to glue the parts together. In the picture, only the wing portion was set up.

I think you'll find that 1/32" plywood is a little better for the hinge gaps..

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"They will say you are on the wrong road, if it is your own." -Antonio Porchi

May/June '97. A few issues later, some genius came up with the idea of 1/64" plywood "spine" in the LE & TE (instead of 1/16" x 1/2" balsa), in which he left gaps for the hinges. No hinge slots to cut...what a concept! Steve

Steve,

I have built both stabilizers and elevators with 1/64" and 1/32" ply used as you suggest, hinge pockets cut in the ply.

While this appears to be a good idea, and I can certainly understand how some might like it, shortly after running completed parts across my gram scale they went in the scrap box.

Dan,

>>While this appears to be a good idea, and I can certainly understand how some might like it, shortly after running completed parts across my gram scale they went in the scrap box.<<

This from a guy with a 72oz. Impact.

OK, I'm ducking and running.

Randy Powell

---who owns a few 72 ouncers of his own

>>While this appears to be a good idea, and I can certainly understand how some might like it, shortly after running completed parts across my gram scale they went in the scrap box.<<

My dear blubbering Unsanitary Dan,

You need to FIX that gram scale! I can imagine it throwing lots of perfectly good stuff into the trash bin.. Try actually weighing the parts instead of running them over the scale and into the scrap pile.

Seriously though, as one who passes the complete Engineer's Test (Engineer: someone who measures with a micrometer, marks with a piece of chalk, and cuts with an axe), I place your concerns in the same category as trying to save weight by using ultra soft 1/16" balsa for ribs - I believe Gary Marchand's term for it was "measuring mouse turds": very diminished returns.

Look at the density of the balsa you had to use to get straight material for solid spars (hey, spruce works very well!), a laminated spar can actually use very light sheet wood and end up straight and strong.

Besides, an instance of tiny fractions of an ounce in the wing cannot be blamed for a ship that weighs a pound too much. Stop painting with a long-haired roller dipped in lead filings, Dan!

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"The only difference between a tax man and a taxidermist is that the taxidermist leaves the skin." -Mark Twain

I too used to be afraid to cut hinge slots, and built a few trailing edges with the slots built in. But not any more......

I bought a Great Planes hinge slot cutter.

Man, I love it.

Maybe I mis-read your request, but there's a "Revisit of the Lincoln Log Wing" in the Nov/Dec 2003 Stunt News. There are differences . . .

Dan,
>>While this appears to be a good idea, and I can certainly understand how some might like it, shortly after running completed parts across my gram scale they went in the scrap box.<<

This from a guy with a 72oz. Impact.

OK, I'm ducking and running.

Randy Powell

Randy,

As well you should. My latest Impact came from the shop at 70.12 ounces.

While still a porker, there was an extra ounce of tip weight installed and I have been creatively drilling various pieces.

I'll be okay. Unless Godzilla convinces me of the wisdom in installing one of those wretched Perry fuel pumps.

And my sincere congratulations on your latest. I understand it to be nearly a pound lighter than my most recent efforts. Dang it...

Dan,

It was before I started finihing it. About 50 oz. complete without finish. We'll see when it's done (should be in the next couple of days). I'm almost afraid to put it on the scale for fear that the weight elves came in the night and filled the belly with magic led or something.

The Tom Morris Linclon Log wing leading edge uses
Two - 1/2" x 1/4" balsa stock pieces
One - 1/16" x 1/2" Balsa Center piece.

The trailing edge is comprised of
Two 1/4" x 1/4" pieces.
One 1/16" x 1/2" center piece.

This is one of the best ways I have found to build a warp free, leading and trailing edge. I have built and flown several of Tom's
airplanes and at the present I am building a new Profile Cavalier.

I believe the plywood thing is just that a thing. For what it is worth, build your wing as shown by Tom. The ply or Bass wood will only add weight.

Any strenght derived from the plywood will be negated by the weight gain. The Lincoln Log wing will build very light and if all of directions are followed you will not have a stronger wing.

In the original article, the TE piece was 1/4 x 3/32. In the Revisted article, he changed it to 1/4 X 1/4. If I were to get the current jig from Tom Morris, which one will it support.

>>If I were to get the current jig from Tom Morris, which one will it support.<<

I suspect whatever you want. Tom's a great guy. Just call or email him and ask.

I believe they come with slots for the 1/4" x 1/4" pieces, unless you ask for something different. Therefore the slot will be 1/4" (deep) x 9/16" (high). These are the opening dimensions in the blocks he sold when I bought mine at VSC or Brodak's (forgot which).

Serge,

Very cool; a wing in a box. Bet it's straight.

Randy-

Thanks. It was as close to perfectly straight as possible, UNTIL I got to this stage and had my first run-in with l.e. sheeting. Then it got badly warped. That's all on a previous thread, but after considerable wrestling with it, it seems pretty straight (except - see below).

The gadget surrounding it is one of Tom Morris' building tables. It is more keyed to single tapered wings (straight flap hinge line); so blocks on only one pair of swept edges were ever mechanically braced - not a problem. That's one reason for the iron weights (also from Tom). Unfortunately, while I struggled with the warps, the building table sagged (over straighter bench top), and when I next inverted the wing, I discovered over 1/16" of dihedral! It seems otherwise to be pretty "straight" (untwisted), and the dihedral probably won't hurt things, since the c.g. is high. It's been an adventure...of sorts.

By the way, the t.e. spar shown is not really at the t.e. of this flapless wing. There are stub ribs and t.e. sheeting. The wing is incredibly rigid and now porky - 6 3/4 oz with tips, slider, and central sheeting still to go. I have learned a lot. One thing is that if one uses a lot (!!) of parts to save weight, he can gain it all back in glue. Still, the jig blocks were a good inexpensive low-tech method, and I'll probably use them again. Definitely not as nice as your set-up, but pretty dependable. I probably would have avoided the warps with yours or Al's methods though.

Serge

Serge,

The advantage of the adjustable system I'm using is that you can insure that the jig is dead straight regardless of weather the base if flat. Certainly an absolutely flat base makes it easier to insure the jig is straight, but you don't have to have one. I use a laser alignment widget to shoot down the jig blocks to set up the lower part of the chocking. The only part that is critical is insuring that the base you set the laser widget on is absolutely flat and that it is the same for both LE and TE. I use a set of fine levels to adjust the base the laser level sits on. Do that and the rest can be set up flat and level.

Sure has made a difference in my ability to generate a flat, square structure.

Tom's new wing jig blocks accept the new measurements of
Leading edge of 1/2" + 1/16" + 1/2" = 1 1/16 inches.
Trailing edge of 1/4" + 1/16" + 1/4" = 9/16"

This is a very easy way to build a warp free wing and one heck of a way to build it straight.

I have one of Tom's new building boards and a couple sets of the jig blocks. I have also cut jig blocks for other wing configurations like Brodak. Sig and others.

I suggest that you give Tom a call he will glad to talk with you about any of his products.

Serge,

What's the plane you're building in the photo?

Kim-

It's an original profile design that I drew up last year, when I decided I wanted a sharp turning plane that wasn't a combat plane. It is a short coupled, highly tapered, high aspect ratio (~6.3 - 6.5), flapless design for an LA .25. Airfoil blends from 19%-20% and has max thickness at about .24c - generated using Profili. 56" span and about 480-495 in^2, depending on final trailing edge treatment. Similar to an old "Whipsaw" in planview, it may be a handful to fly, but I'm looking forward to it.

Serge, I'd love to se a pic when it's done. I've got a half built, semi-profile that is high aspect and flapless with an interesting configuration. I'll probably finish it up when I get the current PA plane finished; probably this weekend. It is about 600 sq inches with a slightly different layout of the tail moment and tail plane along with a somewhat different airfoil concept. Just a weird idea I had that I wanted to try. Not a competition plane at all. It will have a PA .40 and pipe. I've got a couple of these "proof of concept" (or lack thereof) planes kicking around the shop. Sure can be fun...and, uh, exciting to fly.

I'm looking forward to seeing that one!

Serge,

Here's a sneak peak at the new PA plane. Still rubbing it out and fixing some minor screwups. I did weigh everything and, surprise, it's actually fairly light.

Randy Powell

Sorry, didn't mean to hijack the thread. But the thing was built with a Lincoln Log sort of wing structure. Even got in the elliptical taper.

Magnificent..

I like the appearance of the large stylized stationary root and tip flaps, and the diagonal cuts on the flaps. (I don't know what they mean aerodynamically, but they certainly are attractive!)

Paint scheme design is also excellent.

Looking forward to the flight report.

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"Twenty years fron now you will be more disappointed by the things you didn't do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover." -Mark Twain

Me too! Great!

>It's an original profile design that I drew up last year,
>when I decided I wanted a sharp turning plane that wasn't a
>combat plane. It is a short coupled, highly tapered, high
>aspect ratio (~6.3 - 6.5), flapless design for an LA .25.
>Airfoil blends from 19%-20% and has max thickness at about
>.24c - generated using Profili. 56" span and about 480-495
>in^2, depending on final trailing edge treatment. Similar to
>an old "Whipsaw" in planview, it may be a handful to fly,
>but I'm looking forward to it.
>
>SK

Serge,

Very interesting. Pls do give us pix and a flight report when the time comes.

Thx,
Kim Mortimore

Larry,

>>(I don't know what they mean aerodynamically, but they certainly are attractive!)<<

Well, I had a thought about containing diagonal air flow, but in reality, they just look cool and probably don't do anything.

But they DO something! They lift the soul.

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"I do not have much patience with a thing of beauty that must be explained to be understood. If it does need additional interpretation by someone other than the creator, then I question whether it has fulfilled its purpose." -Charlie Chaplin

Randy mentioned using a laser to align the jig supports in the Lincoln Log System. Another very easy method is to use a taut straight line of sewing thread stretched between the end supports then align up the middle supports just to the thread. Thread is very light and the cantanary (sp) curve is slight or imperceptable in this configuration. I used this method to align the bearing supports for the flaps and elvators on my Lancair with great success.

Bob Smiley
A Lancair 360 builder/pilot trying to be a modeler