A tinkerers Toys

[Dave S]

Although I have never achieved the status of "tinkeringhood" that Lowell has, wanted to take Lowell's invitation to share a very small effort in that direction.

Back a while this year I decided to add a rudder trim....probably no big deal except that some of the more elegant designs that were done by builders on this list who made their modification before the fabric was on......too late for that in my case so it had to be an add on.

Here's some photos and a description of my thought processes.

1) Our friend from Oz on the list was kind enough to share what tab size and position on the rudder worked for him. Both measurements worked out perfectly.

2) Checking how simple add on rudder trim tabs are done on other aircraft, with one observation that normal certificated tube and fabric aircraft which have thick trailing edges due to the tube frame often have the tab on the right side, bent around behind the trailing edge so I decided to try that. I figure the tab is "lifting" the rudder to the right anyway and this installation allowed for less of the tab sticking out in the airstream on the left side.

3) Rather than having a sharp bend in the tab, decided to go with a curved bend which theoretically might allow for a smoother air flow over the tab.

4) In fastening the tab to the rudder I decided to go with the 3M double sided high strength trim tape....since it comes in 1/2" wide strips, it was necessary to use two strips to account for the one inch wide contact. One caveat with the adhesive method is the paint must have been prepared and applied correctly so there is no delamination of the paint layers....thought about that and it has not been a problem. Considered the traditional drill the tube and use screws; but, I like to stay away from that to avoid potential moisture penetration of the tubing.

5) The two holes in the corner of the tab are not some super-secret-vortex-generators....just a practical way to support the tab for painting before it was stuck on the plane

The last photo is looking up from the bottom to show the amount of curvature which resulted in a hands and feet off cruise.