Flight Club - Ultralight Build Log

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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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