Trailing edge bend

[epapa]

I have not been successful in searching for anything on the trailing edge fancy bend. I do not really have a method of doing that. Has anyone done it any differently?

[Chris In Milwaukee]

Is the problem that you're not able to bend the trailing edge far enough? I presume that this is the trailing edge for your ailerons/flaps?

Aside from buying pre-made trailing edge material like this:

http://www.aircraftspruce.com/catalog/mepages/trailedge.php

If you're bending you're own, you'll probably have to take the aluminum that's been initially bent *under* the foot of the brake and place it in *front* of the foot so that you can bent it further. Under the foot, you'll probably not be able to bend it that far. Sorry I can't find a photo that describes what I'm talking about here, but it's basically "squishing" the bend so that that sides are closer together.

[BTAZ]

At the time I was building my wing I used hand seamers and very carefully made the joggle. Worked but wasn't much fun.

Later on, I purchased a bead roller set like this one(http://www.eastwood.com/bead-roller-...-mandrels.html) and modified it to be "useful". If you do a web search, you will find lots of different threads on upgrading it. One of the most important is to carefully rework/polish the dies so that they don't leave a mark on the material.

I would guess if I needed to do it again it would be my tool of choice. It definitely came in handy for a lot of tasks and I wish I would have gotten it earlier in the build.

[epapa]

I have had one of those in my shop gathering dust for 25 years. I even forget what I bought it for but is was no fun to use and the results were not pretty. Thanks.

[BTAZ]

I expect I probably should have asked which "trailing edge" you were asking about.

Since the LSA doesn't have flaps, there is a "joggle" in the lower trailing edge wing skin. Forming this joggle is what I was talking about in my earlier post

For the aileron trailing edge, I bent up the general form at the same time I bent my spars. I closed the bend further by putting it in between a heavy door and the door jam on the hinge side and carefully closed the door as required.

Otherwise, I suspect you could adopt what Aircraft Spruce sells here http://www.aircraftspruce.com/catalo.../trailedge.php

[Chris In Milwaukee]

Ah yes, that didn't even click in my brain, the lack of flaps on the LSA. I hadn't considered a joggle at all, on those surfaces. Makes sense, looking back.

[BTAZ]

As delivered, it isn't terribly useful.

With a bit of work to stiffen it, mount it, provide a fence, provide an easier way to turn the rollers instead of the crank provided, and polishing the dies, I found it quite useful.

I find that the case with a lot of the HF tools. They are a decent start but are a project unto themselves before they are useful.

[epapa]

I have decided to do this for my trailing edge. Please comment on that you think as far as riveting the wing skins and closing them up. I do not like #4 because water could get between the skins. I also have a second question....do you overlap the skins at the same point? It seems to me it would make a layer of 4 skins on the corners. Thanks.

[BTAZ]

I would be curious as to why you wish to do this differently than the plans? It doesn't look easier to fabricate and definitely will need a lot more blind instead of solid rivets.

I can see where It may be more cosmetically pleasing and certainly less likely to cut you when you walk into it. The plans method will leave you with a nice straight scar on your forehead instead of the more traditional "Cessna diamond".

So if Bob is OK with it, I would vote for number 4. Any of these will need to be finished out by blind rivets. It is the only one where the blind rivets would both be on the bottom as well as be logical from an airflow point of view. I would think would be the cleanest look and also the most water tight, Sitting in the three point attitude on the ground, water would need to flow uphill to be able to flow in.

[epapa]

I didn't think about sitting in a 3-point attitude. Good point. Check out the screenshot of flaps and ailerons from my RV in the pictures below. It may have contributed to my decision.

[epapa]

Very similar.

[BTAZ]

Unlike the RV,(which I assume runs the skin from spar, around the rib tail, and then back to the spar), you will need rivets in between the ribs for the seam. My guess is these would need to be blind rivets as I don't know how you would buck them.

I had thought that perhaps you could use a single skin in a similar fashion but I'm not sure how you can buck the rivets. I would guess that is one of the reasons Bob approached it like he did. It minimizes the number of pull rivets.

[stinger]

Different Strokes. Maybe you are talking about something like this. I had no means of bending a long section of metal , so this is the way I approached the problem good or bad. Stinger