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maya.ayoub.32

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A detachable rudder and tail would be a good idea IMHO, for when you have to do repairs or fabric replacement in the future. There is a concept in engineering design that seems to be ignored a lot. That is "Design for Maintenance"---make it easy to do repairs and routine work (I had a car once where you had to take the center dash board apart to replace a backlight fuse!!!)
Amazing!! With this green light on the detachable tail, the Airdome hinges perfectly match our needs and we wouldn't even have to create our own hinges. Thank you for the consideration for maintenance too - that's the main reason we were concerned with the rib stitching, but taking it into consideration for the body of the plane as well is great advice!
 

maya.ayoub.32

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No use the piano hinge as a hinge....all of the concepts shown will work ....if you keep the tubes true/straight/parallel you should not get binding.
Thank you so much for the clarification! I completely understand now and I appreciate the drawing. Because we're now moving to a detachable tail for maintenance + logistical reasons, we can stick with the IArdome hinges we already bought. However, knowing we can use hinges for the tail control systems is very useful information nevertheless and would be a good backup. Thank you again!
 

maya.ayoub.32

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Yes, I can’t recall Ray ever approving a wing cover without rub stitching.
...
I’ve heard estimates around $4K, but I am not sure if that is the entire plane of the wing alone.
Gotcha! Okay sounds like rib stitching is a necessity for safety concerns. We haven't glued our fabric yet which is probably a pro at this point considering this forum has so many great suggestions for other fabric attachment brands. Also, thank you for confirming the PolyFiber manual! Do you have any recommendations on where to get the rib stitching material?

We were thinking of using the poly-fiber rib lacing cord: POLY-FIBER RIB LACING CORD | Aircraft Spruce
And some pretty standard needles: RIB LACING & SEWING NEEDLES | Aircraft Spruce

As for fabric, we got our off Aircraft Spruce that PolyFiber recommended for uncertified planes: POLY-FIBER FABRIC UNCERTIFIED LIGHT | Aircraft Spruce

We've done a bit of testing with attachment (oh lord bare foam with their products was NOT a good idea):
1616871280681.png
It worked pretty well! We haven't tried rib stitching yet but we'll let this forum know as soon as we do!

And thank you for the tips on saving money/ time with UV protection! We're not sure where we're going to store the plane yet since hangers near us are quite expensive, but we can't keep operating out of a garage for longevity issues. Looks like that's the first step haha

Thank you!
 

maya.ayoub.32

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I can't remember the details of your rib construction so this may not apply:

Yes, it is a great time saver, but it isn't an option for some types of rib construction.
The ultralight type foam ribs with a glued on cap-strip of aluminum or composite may be limited by the strength of the foam/bond line when placed in tension.

Internal rib stitching - wrapping the ribs with the equivalent of rib stitching before covering may be an option.
When we tested our ribs the failure came from the fiberglass caps reaching their ultimate tensile strength when in compression. We haven't tested the rib in tension, but I would assume the same as you that the fiberglass/foam attachment will probably be the weak point. On top of bmcj's concern with the fabric itself sticking to our ribs, I agree that rib stitching is the safest method. We'll have to test out internal rib stitching, but that might not fix the fabric itself separating?
 

maya.ayoub.32

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A small piece of cotton sheet draped over the top of the rib at 30% will allow using a hook needle to stich through the cotton . This puts everything in shear.
Gotcha! We'll test it out thank you!

Just sent you a link to our Oratex folder which contains all of the information we were able to assemble on the subject. Let us know if you have any questions.
Yes got it! Thank you so much!
 

maya.ayoub.32

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using the ultra-lite method and one of two colors of Poly-tone that already has the silver in it......you should save weight and cost......If you decide to use the Polyfiber method.......Use non certified fabric. ....for example.....remember a yard of this fabric is 72" x 36" when figuring square ft.....(18 sq ft).....to further cut down on cost there is always Latex house paint .......
Ceconite Fabric - Wicks Aircraft Supply Company
This is amazing! If we don't need to pay for paint, there's basically no down-side to using Poly-Fiber. We did end up using their non-certified fabric bought off Aircraft Spruce < POLY-FIBER FABRIC UNCERTIFIED LIGHT | Aircraft Spruce > , and thank you for letting us know about this trick before buying all our glues!
 

proppastie

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no down-side to using Poly-Fiber.
the two colors of the Poly-Tone with the silver in them are Poly Fiber Paint......But I understand what you meant. I believe the MEK in the Polyfiber PolyBrush and PolyTone will dissolve your foam ribs unless I missed a post on how you will handle that.....You might add 2 coats of PolyBrush to the existing test fabric panels post 323 and see what it does to the ribs.
 
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Rudy Lee

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Apr 26, 2020
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One more fabric covering question: I've just finished reading through the poly-systems covering manual and the only thing I still don't understand is exactly where/what we should be gluing the fabric to. In the manual, it says to only glue it down to the trailing edge, leading edge, butt rib, and wingtips (ie no gluing to ribs themselves, other than the ones on the ends of the wings). The main problem with this for us is that we don't have a leading edge :fear: (well at least not one that we can glue to). I know that a reinforced leading edge is not necessary, as scallops aren't a bad thing, and that other aircraft (like the affordaplane and more) get away with fabric covering and no leading edge. How should we go about gluing our fabric? Should we just glue it to all of the ribcaps? or?
 

Aerowerx

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....The main problem with this for us is that we don't have a leading edge :fear: (well at least not one that we can glue to)....
You have to have a leading edge. Isn't there a rounded part at the front of the airfoil? You could just run a strip of something spanwise at this point, then glue your fabric to it.
 

Rudy Lee

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You have to have a leading edge. Isn't there a rounded part at the front of the airfoil? You could just run a strip of something spanwise at this point, then glue your fabric to it.
Yeah, I think this might have to be our solution. We read that leading edges weren't necessary as scalloping wasn't an issue. But I suppose it would be necessary for the fabric attachment. Do you have any recommendations about leading-edge material? We tried our super-thin (can't remember exact thickness, sorry) aluminum sheets but they just didn't want to adhere at the proper arc.
 

Rudy Lee

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Apr 26, 2020
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Would it work to have our fabric overlap around mid-chord instead of on leading and trailing edge? That would solve our problems
 

Rudy Lee

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Apr 26, 2020
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Awesome! That makes sense. Now we can seam it in three points - trailing edge, and both the top and bottom of our rib support blocks around 40% chord
 

bmcj

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One reason for not gluing to ribs is that you want the fabric to be able to shift and equalize the tension across the entire surface when you begin heat shrinking it. If you glue it to the ribs, then bay tensions may differ and it will start pulling your ribs out of straight alignment. Once the fabric is taught from shrinking, then your paint application will soak into the weave and provide light adhesion to the ribs and skins.
 

TFF

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Ok in a previous drawing there is a thin leading edge; is that gone now? If you removed that, I think you will have an airplane that does not fly well. It takes the impact of the air. I’m not saying it will not fly, but the airfoil will be changing constantly with the air hitting it. It will take a lot of skill to fly it. A leading edge is also first line of defense to hitting a bird. You don’t want all the ribs to be broken and loose shape. It will not fly enough to make an emergency landing. Glueing at the the spar is fine as long as it is a secure spot. Plenty of real covering jobs do this to hide a leading edge seam for looks, but they still glue to the leading edge.
 
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