Make Your Own Fanfold Flanker - Page 2 - RC Groups
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Jan 16, 2004, 02:51 PM
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Thomas Nelson's Avatar
So I wasn't imagining things. I really DID hear a "bump" at 6:30 in the morning!

Here's a start. Open this file in MS Paint and print (and tape together) two copies. One for your wall, and one to cut apart.

Update 2004-01-31 ... tn (new link to drawing - no bandwidth limit. Thanks Dru!)
To work with the templates this drawing should be scaled such that the ws is 23 - 15/16" from outside of missile rail to outside of missile rail. And the length is 35 - 1/4" right up the datum line (top view) but NOT including the antenna. Don't worry if your drawing is a little different. This construction technique is very tolerant of this, and let's face it ... this plane isn't about to compete in Scale Masters!

By the way:
This file is an enlarged copy of one that is all over the internet. I've no idea of its originator, and so do not have permission to use it. I "doubt" that posting it here is likely to cause a problem, but if someone feels (or knows!) differently, I'd appreciate a 'heads-up'. If necessary, I'll use it as the basis for my "own" drawing and post that one.
Last edited by Thomas Nelson; Feb 01, 2004 at 12:12 AM.
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Jan 16, 2004, 04:16 PM
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The attention to detail is fantastic! Let me also say that when I found the RCGroups site and stumbled on your Flanker, i was instantly struck with amazement. After years of building balsa models, I never heard of fan fold, or even believed that anyone could build a plane as detailed as yours.

I'm really going to enjoy this

Jan 16, 2004, 04:24 PM
U.City Flyer
bmizes's Avatar

Your flanker looks amazing. Jets are one of the few planes I don't own, but I'm hoping your plans will rectify that shortly.

Jan 16, 2004, 06:47 PM
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Thomas Nelson's Avatar
Thanks for the kind words, guys!

Next step is to download this drawing and print it in color. You'll see 4 layers, each represented in a different color. Cut 'em out of fanfold. These layers will be stacked on top of each other as shown on this drawing, and sanded to form the concave fuse-to-wing blend.

Note that this drawing is not to scale, and really doesn't need to be. Just use it as a guide to hand draw each layer - no need to even print it, really. Don't worry about being too precise. Just get each layer close. There isn't really a need to go through another print/tape/cut exercise for this step.
Edited 2004-01-31 ... tn (removed link to my webpage and posted the file here).
Last edited by Thomas Nelson; Feb 01, 2004 at 12:06 AM.
Jan 16, 2004, 06:55 PM
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Thomas Nelson's Avatar
Before gluing any layers, reinforce Layer 1 with carbon fiber. Feel free to rely on your experience and judgment. I made a CF spar with balsa shear web for the loads the wing would see. And I used a CF tube as a support for the motor. Don't skimp on your motor support; between the weight of a Mega and the loads seen while landing, you want this area to be solid.

A word on the location of the wing spar:
This wing will bend torsionally. If it is allowed to bend such that washin is introduced - say when pulling out of a dive - you're in for a nasty tip stall. I tried to locate the spar such that under positive G's the rear of the wing will deflect more than the front. Resulting in washout. Proof's in the puddin ... my previous fanfold Flankers had no problems with tip stalls.

Again, use your own experience here. Some may opt to glass the wing (on the bias) and will thereby minimize wing-twist. Wouldn't need a spar at all in that case.
Last edited by Thomas Nelson; Jan 17, 2004 at 12:35 AM.
Jan 16, 2004, 07:08 PM
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NOW you can glue on the other three layers. Use spray-on adhesive that sands easily. I like old formula 3M-77 for this.

I really regretted that I couldn't find a way to form the concave portions of the fuselage from a single sheet of fanfold. But, in my experience, the only way to get acceptable results was to build up the layers required, and then sand back to the compound-complex curves. Don't worry, though. This isn't especially hard with the right tools.

But I'm getting ahead of myself.
Last edited by Thomas Nelson; Jan 16, 2004 at 07:46 PM.
Jan 16, 2004, 07:20 PM
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I WAS going to the shop after supper and work on my DC-3, but then I can do that another day... I feel an F-15 coming on...

Thanks for the inspiration......BEAUTIFUL WORK>>>>
Jan 16, 2004, 07:21 PM
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Thomas Nelson's Avatar
Now you can begin shaping the fuse-to-wing filet. This is done in two steps;

1. The profile. In essence, you are sanding a flat-bottomed airfoil into these layers.

2. The concave portion. I mention it now so you know where we're headed. But we'll get to this step a little later.

For now, concentrate on sanding away the layers such that you are left with an "airfoil" shape. Remember the drawing in post 19? Notice that each layer's color is shown in profile.

This step (1) is not particularly critical. Might seem so, but it isn't. The turtledeck will conform to whatever shape you end up with. So once you've got the gist of the shape in your mind, grab a sanding block and have at 'er.

Oh - it will help if you place masking tape directly adjacent to where you are sanding. At the wing roots and tail, for instance. This will prevent errant sanding strokes from scuffing those areas.
Updated 2004-02-02 ... tn (added the 'tape' comment)

This thread - from my second fanfold Flanker - might help some too.
Last edited by Thomas Nelson; Feb 03, 2004 at 01:24 AM.
Jan 16, 2004, 07:28 PM
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Thomas Nelson's Avatar
Glad your enjoying it, Jerry!

Here's another pic showing where you're headed. Maybe it looks hard to do, but it's not.

BUT don't start sanding the concave part yet! You need to make the forward fuse/turtledeck first. This will serve as a guide, allowing you to trace the lines TO WHICH you will sand the concave part. You can just make out the white lines above.
Edited 2004-01-27 ... tn (clarified that the concave part is sanded later)

I see that I need to take some pics of the sanding tools needed. I'll pick things up in another hour or so.
Last edited by Thomas Nelson; Jan 27, 2004 at 11:39 AM.
Jan 16, 2004, 11:27 PM
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Have been waiting for this thread a long time!


The second model, the red white and blue, did you build it with the high point of the 4 fuse layers moved back 2" ?
Jan 16, 2004, 11:30 PM
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Absolutley amazing! Can't wait until I develop some skill so I can do it.
Good show!!
Jan 17, 2004, 12:13 AM
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Thomas Nelson's Avatar
Thanks, guys!

All pictures were taken while constructing the red, white and blue model. So this model does not incorporate the extra two inches mentioned.

As this picture illustrates, the extra length WOULD help with scale fidelity, and I will incorporate it into the next one. And I wouldn't hesitate to do it with the existing templates, but just keep in mind that the turtledeck template MAY need some custom trimming to pull it off.
Jan 17, 2004, 12:59 AM
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Thomas what an AWESOME job you have done! That's just incredible.
Jan 17, 2004, 01:24 AM
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Thomas Nelson's Avatar
Gracias, Hawker!

Earlier I mentioned that the fuse-to-wing filet isn't that hard to make - given the right tools.

Besides basic sanding blocks that all foam builders already have, I've found three key sanding tools make short work of this particular part of the build.

1. Sponge sanding blocks. These can be squeezed into convex shapes allowing me to sand concave shapes with ease. Get Very Abraisive sponges! I'd estimate the equivalent of 40 grit is my most abraisive. You want to use a very light touch when using these - minimal pressure deforms them less, and lessens the likelihood of tearing any foam ... especially when sanding through glued layers.

2. Dowel wrapped with sandpaper of various grits. Self explanitory.

3. A 'magic' little gem made of spring steel. It's what I've attached here. It has dimples all over it, making it the equivalent of (say) 100 grit. When squeezed, it forms a very consistent radius. Further, it works well when sanding through glued layers. It's especially effective at removing the hard, high spots without digging into adjacent softer foam.

Other tools work too. Rasps, and files all have their place. But these three make the biggest difference with the concave areas.
Last edited by Thomas Nelson; Jan 17, 2004 at 10:44 AM.
Jan 17, 2004, 01:25 AM
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Here's what you can do with an abraisive sponge;

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