Rolling leading edges

Here is my 2 cents worth.
After searching the forum on how to roll the leading edges on the elevators and rudder and finding a lot of useful info I thought I might publish my method.
I decided to go with 2 techniques I found here. One is clamping down the pipe with wooden blocks and the other is using a plastic sheet under your work to allow the part to slide while rolling. After finding varying thicknesses of pipe or broomstick here I decided to use the closest I could find to the recommended vans thickness of one half inch, in my case 3/5 inch conduit.
While looking through my shop to find something to use as a t-bar I ran into these. Pipe wrenches.



How easy is that. Stuck one of these in the end of the pipe and turned it with a socket wrench to bend the ends up just past 45 degrees. I started to bend the sections separately on the one side but seeing as though it went so smooth I decided to bend all three at once on the other side. That worked just fine.







Hope it helps..

Nice Idea

It's been years and years since I bent mine, but I still remember struggling with it. Wish I'd thought of this....

Heh heh, plus one for me too!

Mark Dickens said:

It's been years and years since I bent mine, but I still remember struggling with it. Wish I'd thought of this....

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One thing is for certain, just when you think you have found the latest and greatest "best" way to do something, somebody else comes up with an even better, easier way to do it. I love this site! Thanks to the OP for posting this.

Initially bending then edges to only a 45 degree angle is also an important detail about this process that should not be overlooked. Now I want to find out how the "rest of the bend" went? Nobody seems to post much about the additional effort it takes to finish the bend process by hand to finish closing the edges to their final position. I found that this largely needed tobe done by hand to get it just right. I am curious if he has also found an easier way to do that as well.

45 degrees?

Why would you only bend to 45 degrees first ? I assume its to reset the pipe

Why only 45 degrees?

Arie said:

Why would you only bend to 45 degrees first ? I assume its to reset the pipe

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Vans states in the manual that this is an initial bend only. It will not close up the ends to their final position, nor is it intended to do so. You still need to finish the rest of the bend by hand or by some other method to place the LEs in the correct overlapping position so they can be riveted together. This final bending process results in about another 40+ degrees or so of movement. If you "overbend" the LEs initially, they will end up curling inward too far when you close them up, making the riveting of the two skins a bit difficult, if not impossible. They won't lie flat against each other by the time the rivet holes of the inner and outer skins are aligned.

I learned about this the hard way with the rudder, but had much better results with my elevators when I only bent them initially to about 45 degrees as stated by the OP. This allowed the edges of the overlapping skins to line up flush with each other with no inward curl.

Maybe others are re-setting the pipe as you suggest for an additional bend, but my experience and research from other builders was that you bend once, and finish the rest of it by hand.

Thank you Bryan, that makes sense. One more question , when you use your hands to do the final bending, do you place a shorter piece of pipe inside the bend, and bend over that ,or do you actually only use your bare hands?

Finishing the LE bend

Arie said:

Thank you Bryan, that makes sense. One more question , when you use your hands to do the final bending, do you place a shorter piece of pipe inside the bend, and bend over that ,or do you actually only use your bare hands?

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Again I will speak from my own experience. For me this is actually a bit difficult to put into words. It is easier to demonstrate it than to explain it. I did not use anything other than my hands to finish bending and closing the LEs. It turned out to be more of an art or a skill rather than a science.

My "method" was as follows:

1. Start with the shorter sections first, since they tend to go together easier, with less resistance than the longer sections.

2. I did all of my final bending/rolling by positioning the skin-to-be-bent on the top side, so that I could apply firm but gentle downward pressure with both hands in a downward direction. (Something about gravity maybe helping this process - yeah right!) Actually it is simply easier to push down on something that to pull or push upward.

3. The technique with the hands is the difficult part to describe. One concern at this point is the potential forcreasing the LE skin where the spar flange lies underneath, which can still happen if you apply too much downward pressure. To prevent this, I basically used the tips of my fingers and the upper palms of my hands to apply a downward pressure on the edges of the skin while trying maintain enough counter-pressure on the skin near the spar flange to keep it from creasing at that point. Perhaps the best analogy I can provide of this action is similar to gripping the handle bars of a bike or motor cycle, and then applying additional force with your fingertips similar to reaching for the hand brake lever on the handle bar. Not the best analogy but there you have it.

4. I too had pondered if I could put another radius near the spar flange during the final bend/roll to try to prevent the skin from creasing, but then I realized that the skin near the spar flange does actually have to bend slightly inward to allow the ends of LE skins to align and overlap. If you try to place any type of radius under the skin near the spar flange it will not allow the skin to close up enough - at least that is my experience.

5. My experience during all of this is that you would try to coax and push and form the LEs into position several times, and it would seem like they would not budge at all. And then suddenly you apply the right amount of force and pressure in the right spot at the right time and you would feel the skin "give" a little and start to come down down a little more. Then you check the fit and keep going until everything is properly overlapped and the rivet holes are aligned.

So your hands have to get used to the feel of the tension of each LE skin, and you just have to keep at it until you find the right amount and direction of pressure from your fingers and upper palms that will start to move them closer together. Once you have completed one section you will understand what it will take to finish the rest of them.

I have several comments and posts in my builders blog (link is in the signature line). Just click on the Rudder and Elevator category links at the top and you can review my comments about this process.

I hope this helps.

Indeed

As Bryan describes is indeed the way I did it too. No fancy method either. I think describing it as gripping a bike handle and then reaching for the brake lever nails it. Unless you have never ridden a bike. If you indeed start with the smaller sections first you do get a feel for the process. Only thing I might add is have the piece lying down with the leading edge furthest away from you. Massage the top leading edge a few times, flip it over and repeat. It seems to go slow at first but be patient, don't try to get it in one go. Eventually it will come together. When finished I was able to hold the pieces together in one hand while inserting cleco's with the other.

I done mine as per the manual but what needs to be remembered is the pipe is only to get the bend started (not over bent) and the rest is worked by hand.