Functional Cowl Flaps Mod

This is a test or prototype for a later CARF Corsair build so I thought Id post some photos. Ive had a lot of problems with the stock TF cowl in the way its attached and the poor hardware. The cowl has come loose several times even with thread lock. It has interfered with the prop and was damaged as well as the prop so being fed up Im redesigning the set up.

Similar to how others have done this before I spaced the main cowl 1/4 ply ring out further from the mounting blocks. I went to Ace Hardware and found #6 hole nylon 1 inch spacers. These were cut down to 3/4in simply by chucking each one up in a basic drill press and using a Zona razor saw against the chucks face you get a nice square clean cut. See photo. I also purchased 3in 6-32 all thread rods and used red thread lock to bond them into the stock mounts.
With the threaded studs at full length I assembled the cowl ring with washers and locknuts before cutting off the extra length. I left a short amount of threads exposed so there is still an adjustment range.

I sanded the outer edge of the cowl ring a bit to adjust the ring to fit further in the owl because its tappered. The cowl was prepared by cutting off the cowl flaps at the panel line. The new edge is aliged to the cowl ring back face. Since the ring is 1/4in thick I decided to use it to thread button head wood screws into it to hold the cowl. See photo.

Now the fun begins, the cowl flaps are not accurate on the stock cowl so you must decide now if this matters. I decided to move on. There should be a "small" flap at 3/6/9 oclock positions so the bottom one is missing as they alternate around.
I used wide nylon hinges and sanded off the dubro logo on each tab. I used 1/64 plywood sheet to space off the hinge from each surface. The geometry is tricky when your trying to keep the leading edge tight to the cowl panel. I put the hinge pin center on the egde of the flap. When it pivots out the flap leading edge will touch the cowl trailing edge.
Between each flap I used 0.010in G10 fiberglass to make the secondary surface.
Im also going to use the super thin and flexible Sullivan cable with the plastic yellow tube. I have some small laser cut wire guides we use for directing remote antena wires that happen to fit the tubing. See photo. I slotted the hinge and glued the guide to the plywood.

Last night I was able to build out the left side and check that the cable works and it did very well. On the bottom 3 flaps I used 1/8in plywood triangles set to 10deg to make the flaps open. I used a plywood sheet and a hardwood block to take advantage of a natural pocket in front of the firewall where I located all the lead weights. Its removable so now these three flaps are attached to this panel and the flaps go completely around the cowl uninterrupted.