Repairing ribs and switching from cable to aluminum trailing edge

[1avidflyer 2025]

Hi all,  I'm in the process of rebuilding an Avid C model.  It had the cable trailing edge on the wing, and a couple of rib tails were broken as well.  As the previous owner had bought aluminum trailing edge from aircraft spruce, I decided to put it to good use.  I ended up using some 5 ply 1/4" plywood for the reinforcements, basically added another rib tail on each side of the existing ones. I also laid in 5 layers of fiber glass cloth and resin on each side between the layers except where the flaperon hinge bolts on, and that left a gap between the original rib tail and the added ones.  The flaperon will bolt on just as it did before, but longer bolts will go through all 3 rib tails and sandwich everything together.  I would have used the 12 ply plywood, but the 5 ply was available and with the added layers, should be much stronger then the original, especially with the fiber glass added.  Added a wedge shaped piece that lined up with the bottom cap strip for the trailing edge to push up against and hold in place.  Also it gives some support to the fabric where it goes from the cap strip to aluminum trailing edge.  I trimmed down the bottom of the intermediate ribs between the long tailed ribs to where the bottom cap strip is.  (part of the 1/4" plywood protrudes through to hold the cable with the old system)    Anyway, this repair/remodel is hopefully of interest to some in the future who are wondering how to make the switch to aluminum trailing edge.   Here are some pictures that hopefully show how I did it.  I fastened the flaperon in place before I cut and fit the aluminum trailing edge.  That way the ribs didn't some how get bent to the side and not line up with the flaperon hinges after everything was glued in place.   JImChuk

PS  fabric is not shrunk, and the wrinkles will go away with a bit of iron work

Edited 29 Dec 2024 by 1avidflyer

[1avidflyer 2025]

In the event that anyone is wondering how the C model Avid is doing, One wing is almost ready for spray coats and the other wing will go in the rotisserie shortly.  JImChuk 

[ChrisBolkan 151]

Clever. That looks PLENTY strong!

[Vmx136 2]

Jim been waiting for days for an update. Seems you and Chris are the only ones getting anything done.  Thanks for keeping some excitement flowing on this site.

Scott in wv.