Trim tab - Lower leading edge

[Lorin Dueck]

All -

Okay.... this is one of those extreme emotion days!!

I got home tonight and immediately went to work on the HS trim tab.
Everything was done (and it was lookin' good) - except bending the lower skin to miss the adjacent skin on the HS.

Using a block of hardwood - I started to bend up the lower skin by rubbing the block along the spar at a slight angle.
First attempt (trying to go slow and not pressing too hard) - not much hapened.
Next time - pressing a little harder - I got a few sections (near the rivets) to take a set.
Third time pressing even a little harder - and moving as smoothly as possible - I got a fairly consistent crease in the lower skin along the spar.... but the forward edge of the lower had HUGE waves.

Apparently - the aluminum stretched in some places but not others.
I would not have thought the skin would stretch as much as it did!!
It was awful!!!

Thinking back - I should have "pressed down & bent" as opposed to "pushed along & bent".
Bottom line is "time to build another trim tab".

I guess this is the "education" part of amateur built "for recreation & education".

Given the family oriented nature of this site - all I can say is " Rats.... I realy wished I hadn't done that".

Lorin D.
emp and wings....... and that darn trim tab!!
(N194LD Reserved)

[jim_geo]

I did the same thing tonight except I used a pair of hand seamers. The same pair I used to do this



Turns out to be a useful tool for me. I still don't quite know what you're REALLY supposed to use them for. Kind of a wide pair of pliers maybe I could use them on stained glass projects. Anyway, It only took a very slight bend and was finished. I feel your pain, the trim tab is one of the more difficult parts to build if only for the rivets being so hard to get at.

[cjensen]

i decided to say "screw it" on those rivets on the bottom of the trim tab! i don't have a longeron yoke, and in hindsight, i should have backriveted them before i ever bent the skin. i just used CS4-4 blind rivets. it's on the bottom, so don't tell anyone else...ok!?

[tshort]

Jim-

Where'd ya get those seamers? They look like a particularly nice pair. I could use a good set ... mine are from the Yard and are great, but yours look a little better (never can have too many tools.... )

Thomas
-8 flaps

[jim_geo]

Those seamers are from Cleveland. Hey am I usen those things right? They are cool lookin though.


Chad, Tomorrow I'm taken a picture for you of the way I got at those #%$@ bottom leading edge rivets. It may make you laugh. Worse than that though, for me, was the rivets holding the control horns on. I finally discovered that I could use the corner of the table on the band saw to buck the rivets without having to open the ol trim tab taco up to far. Only had to redo one.

[Spike]

Just consider it part of the learning curve Lorin Rebuilding a trim tab is better than rebuilding oh say, a hole blessed HS half because of a trashed spar. Been there done that. Remember, this is fun!!

[jim_geo]

So as promised here are some pictures for Chad. Nice work by the way Chad. Your parts are coming out real nice. Anyway this might make you laugh at what a Mickey Mouse set up it is but it worked well. This bucking bar reaches right around the trim tab leading edge spar. Hint use some tape to hold the rivets in place, Your hands get pretty full.




Next is my favorite bucking bar. The bandsaw.
most of the bucking was done right up close to the corner there (I've also used my table saw as a back rivet table, worked well ).




The bandsaw bucked the rivets for the control horn. Sorry I don't have pictures of actually doing the work. If anyone wants to send me thier parts I would gladly do a photo essay for them. Hmmm well maybe.

[cjensen]

those are actually great ideas jim! doesn't matter how mickey mouse they are...if it works, it works!