Rudder Trailing Edge

[Anitech]

Hi to all,

I am about to build the rudder and all is understood so
Far. However, if anyone could elaborate on how you put
The slight bend in the trailing edge of the skins I would like to
Learn from your experiences. Also, how you clamped down
The TE during the sealant cure time.

Thanks in advance,
Steve

 

[flion]

I used the 'puck' edge roller. You just want to put a very slight curve in the edge, not a visible crease. Whatever edge rolling tool or method you use, practice on scrap first; it's really easy to overbend.

Once I had prosealed the wedge in place and secured it with clecos, I draped it over the edge of a flat panel (I use a door blank as a worktable) so the protruding end of the cleco (not the barrel, the clamping end) was up against the edge of the panel. I then laid a straight piece of 4x4 on top of it (the barrels of the clecos kept it from sliding off) with a little extra weight to keep everything firmly in place.

Once the proseal set, I cleaned out the dimples with a countersink bit spun by hand. Then I set the rivets as described in the instructions.

 

[paul330]

Good advice. The puck tool is useful but easy to screw up - ask me how I know this Not only can you overbend, but with too much pressure, it deforms the metal and you end up with a wavy edge. Also, you can run off the edge and distort it.

Another way is to clamp the skin to the table with a piece of timber to sandwich it with the table edge and just use a piece of scrap wood to run along the edge and put a slight crease. Oh, and do it BEFORE you dimple

 

[Ron B.]

Like others on here, I used a straight alum. angle. I think mine was 1 1/2" X 1 1/2" X 1/8" thick. I drilled the angle to match the holes in the TE. The clecos go right through the TE and through the alum angle. The angle now holds the TE straight during the cure. All our TE came out very true this way. The angle was re-used for the other TE also.
Ron

 

[Wayne Gillispie]

I used 8' alum level...

works on your elevators, flaps, ailerons too. You will have holes of different spacing on each side. Cover level with syran wrap before clecoing proseal covered trailing edge assembly or your level may get stuck and messy. Use clecos in every hole and then lay over a straight work bench edge. Weight down with 1/4" steel angle or 4x4 padded first. Don't worry about proseal squeezing out, just cut it with a razor blade when cured 3 days. Sand remaining down smooth with 180 grit. Ensure your avex wedge and skin mating surfaces are not primed. Roughen them up with 180 grit and then use alodine alum etch kit 860 if you have it otherwise apply sealant and assemble. Alodine will be used later on your winshield base fairing to skin joint. It increases bond strength as it prevents corrosion at the bond line. Very little is needed. I got a small aluminum etch kit #860 from Jamestown Distributors.

 

[Anitech]

Rudder TE

Thanks to all for your ideas!

How far back from the TE should the slight
Bend be? Before the hole line or after?

Has anyone tried prep and priming skins prior to
Dimpling? I am using AKZO so I think it
Is tough enough to dimple after it is applied...

Any thoughts?

Thx

 

[paul330]

The bend is outboard of the rivet holes. The idea is to counter the flaring effect on the edges caused by the pressure of riveting.

 

[Ralph Inkster]

Do the slight bend before you dimple the skin. If already dimpled, too late, will be very hard to get that nice edge.
As an aside, throw the edge puck away! The perfect edge roller is sold by Cleveland Tools, it has two bearings attached to a modified vice grip plyers.

 

[flion]

Whatever works for you, Ralph. I can't get good results with that 'perfect' vise grip tool; others have a horrible time with the puck. My problem with the vise grip tool is two-fold: I can't seem to keep it from wandering off the sheet unless I use two hands - one at the roller end pressing toward the sheet - and then I need a partner or clamps to hold the sheet. The other is that I tend to over bend thanks to the leverage advantage of the plier handles. But that's just me; I tend to not have a deft touch.